90-518: The Kawasaki Ki-100 ( キ100 ) is a single-seat single-engine monoplane fighter aircraft used by the Imperial Japanese Army Air Service (IJAAS) during World War II . The Japanese Army designation was " Type 5 Fighter " ( 五式戦闘機 , Go-shiki sentouki , or abbreviated as Goshikisen ) . It was not assigned an Allied code name . In early 1945, 275 Ki-100s were modified from Ki-61s as an emergency measure to accept
180-519: A radiator blind (or radiator shroud ) to the radiator that can be adjusted to partially or fully block the airflow through the radiator. At its simplest the blind is a roll of material such as canvas or rubber that is unfurled along the length of the radiator to cover the desired portion. Some older vehicles, like the World War I-era Royal Aircraft Factory S.E.5 and SPAD S.XIII single-engined fighters, have
270-407: A Spitfire . This is similar to Formula 1 cars of today, when stopped on the grid with engines running they require ducted air forced into their radiator pods to prevent overheating. Reducing drag is a major goal in aircraft design, including the design of cooling systems. An early technique was to take advantage of an aircraft's abundant airflow to replace the honeycomb core (many surfaces, with
360-422: A biplane or other types of multiplanes , which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing configuration and is the simplest to build. However, during the early years of flight, these advantages were offset by its greater weight and lower manoeuvrability, making it relatively rare until the 1930s. Since then, the monoplane has been the most common form for
450-664: A 14-cylinder Mitsubishi Ha-112 -II radial engine in place of the original Kawasaki Ha-40 inverted V-12 inline engine , resulting in one of the best interceptors used by the Army during the war. It combined excellent power and maneuverability, and from the first operational missions in March 1945 until the end of the war, it performed better than most IJAAS fighters against both United States Army Air Forces B-29 Superfortress bombers and P-51 Mustang fighters, as well as U.S. Navy F6F Hellcat carrier fighters. A newly built variant,
540-536: A 14-cylinder, two-row radial engine . The need for a new engine became urgent on 19 January 1945, when a bombing raid destroyed the Ha-140 production plant, leaving 275 otherwise complete Ki-61s engineless. The Mitsubishi Ha-112-II was 54 kg (119 lb) lighter than the Ha-140 and developed the same power but with much greater reliability. Three Ki-61-II-KAIs were modified to carry this engine as prototypes. Chief engineer Takeo Doi with two other engineers redesigned
630-406: A bellows type thermostat, which has corrugated bellows containing a volatile liquid such as alcohol or acetone. These types of thermostats do not work well at cooling system pressures above about 7 psi. Modern motor vehicles typically run at around 15 psi, which precludes the use of the bellows type thermostat. On direct air-cooled engines, this is not a concern for the bellows thermostat that controls
720-540: A cut-down rear fuselage and improved canopy and 118 were produced from May through to the end of July 1945. This version also featured a modified oil cooler under the engine in a more streamlined fairing. The Ki-100-II was fitted with a turbocharged water-methanol injected engine for improved high-altitude performance, mainly to improve interception capabilities against the Boeing B-29 Superfortresses, but only three prototypes were built, and none
810-509: A few specialist types. Jet and rocket engines have even more power and all modern high-speed aircraft, especially supersonic types, have been monoplanes. Radiator (engine cooling) Radiators are heat exchangers used for cooling internal combustion engines , mainly in automobiles but also in piston-engined aircraft , railway locomotives , motorcycles , stationary generating plants or any similar use of such an engine. Internal combustion engines are often cooled by circulating
900-410: A fixed-wing aircraft. The inherent efficiency of the monoplane is best achieved in the cantilever wing, which carries all structural forces internally. However, to fly at practical speeds the wing must be made thin, which requires a heavy structure to make it strong and stiff enough. External bracing can be used to improve structural efficiency, reducing weight and cost. For a wing of a given size,
990-427: A flap valve in the air passages. Other factors influence the temperature of the engine, including radiator size and the type of radiator fan. The size of the radiator (and thus its cooling capacity ) is chosen such that it can keep the engine at the design temperature under the most extreme conditions a vehicle is likely to encounter (such as climbing a mountain whilst fully loaded on a hot day). Airflow speed through
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#17327717812251080-523: A formidable new fighter. Although far fewer Ki-100s were available than Nakajima Ki-84s, it was an important fighter in the Army's inventory. A well-handled Ki-100 was able to outmanoeuvre any American fighter, including the P-51D Mustangs and Republic P-47N Thunderbolts which escorted the B-29s over Japan, and was comparable in speed, especially at medium altitudes. The Ki-100 was a tough opponent in
1170-422: A harmfully false reading. Opening a hot radiator drops the system pressure, which may cause it to boil and eject dangerously hot liquid and steam. Therefore, radiator caps often contain a mechanism that attempts to relieve the internal pressure before the cap can be fully opened. The invention of the automobile water radiator is attributed to Karl Benz . Wilhelm Maybach designed the first honeycomb radiator for
1260-476: A high ratio of surface to volume) by a surface-mounted radiator. This uses a single surface blended into the fuselage or wing skin, with the coolant flowing through pipes at the back of this surface. Such designs were seen mostly on World War I aircraft. As they are so dependent on airspeed, surface radiators are even more prone to overheating when ground-running. Racing aircraft such as the Supermarine S.6B ,
1350-458: A less efficient but simpler construction. Radiators first used downward vertical flow, driven solely by a thermosyphon effect. Coolant is heated in the engine, becomes less dense, and so rises. As the radiator cools the fluid, the coolant becomes denser and falls. This effect is sufficient for low-power stationary engines , but inadequate for all but the earliest automobiles. All automobiles for many years have used centrifugal pumps to circulate
1440-627: A light aircraft, the configuration is significant because it offers superior visibility to the pilot. On light aircraft, shoulder-wings tend to be mounted further aft than a high wing, and so may need to be swept forward to maintain correct center of gravity . Examples of light aircraft with shoulder wings include the ARV Super2 , the Bölkow Junior , Saab Safari and the Barber Snark . A high wing has its upper surface on or above
1530-437: A liquid called engine coolant through the engine block and cylinder head where it is heated, then through a radiator where it loses heat to the atmosphere, and then returned to the engine. Engine coolant is usually water-based, but may also be oil. It is common to employ a water pump to force the engine coolant to circulate, and also for an axial fan to force air through the radiator. In automobiles and motorcycles with
1620-444: A liquid-cooled internal combustion engine , a radiator is connected to channels running through the engine and cylinder head , through which a liquid ( coolant ) is pumped by a coolant pump. This liquid may be water (in climates where water is unlikely to freeze), but is more commonly a mixture of water and antifreeze in proportions appropriate to the climate. Antifreeze itself is usually ethylene glycol or propylene glycol (with
1710-447: A major area of research. The most obvious, and common, solution to this problem was to run the entire cooling system under pressure. This maintained the specific heat capacity at a constant value, while the outside air temperature continued to drop. Such systems thus improved cooling capability as they climbed. For most uses, this solved the problem of cooling high-performance piston engines, and almost all liquid-cooled aircraft engines of
1800-472: A pair of metal or plastic header tanks, linked by a core with many narrow passageways, giving a high surface area relative to volume. This core is usually made of stacked layers of metal sheet, pressed to form channels and soldered or brazed together. For many years radiators were made from brass or copper cores soldered to brass headers. Modern radiators have aluminum cores, and often save money and weight by using plastic headers with gaskets. This construction
1890-407: A pendulous fuselage which requires no wing dihedral for stability; and, by comparison with a low-wing, a shoulder-wing's limited ground effect reduces float on landing. Compared to a low-wing, shoulder-wing and high-wing configurations give increased propeller clearance on multi-engined aircraft. On a large aircraft, there is little practical difference between a shoulder wing and a high wing; but on
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#17327717812251980-470: A popular configuration for amphibians and small homebuilt and ultralight aircraft . Although the first successful aircraft were biplanes, the first attempts at heavier-than-air flying machines were monoplanes, and many pioneers continued to develop monoplane designs. For example, the first aeroplane to be put into production was the 1907 Santos-Dumont Demoiselle , while the Blériot XI flew across
2070-408: A racing seaplane with radiators built into the upper surfaces of its floats, have been described as "being flown on the temperature gauge" as the main limit on their performance. Surface radiators have also been used by a few high-speed racing cars, such as Malcolm Campbell 's Blue Bird of 1928. It is generally a limitation of most cooling systems that the cooling fluid not be allowed to boil, as
2160-470: A radiator is a major influence on the heat it dissipates. Vehicle speed affects this, in rough proportion to the engine effort, thus giving crude self-regulatory feedback. Where an additional cooling fan is driven by the engine, this also tracks engine speed similarly. Engine-driven fans are often regulated by a fan clutch from the drivebelt, which slips and reduces the fan speed at low temperatures. This improves fuel efficiency by not wasting power on driving
2250-413: A separate small radiator to cool the engine oil . Cars with an automatic transmission often have extra connections to the radiator, allowing the transmission fluid to transfer its heat to the coolant in the radiator. These may be either oil-air radiators, as for a smaller version of the main radiator. More simply they may be oil-water coolers, where an oil pipe is inserted inside the water radiator. Though
2340-507: A series of shutters that can be adjusted from the driver's or pilot's seat to provide a degree of control. Some modern cars have a series of shutters that are automatically opened and closed by the engine control unit to provide a balance of cooling and aerodynamics as needed. Because the thermal efficiency of internal combustion engines increases with internal temperature, the coolant is kept at higher-than-atmospheric pressure to increase its boiling point . A calibrated pressure-relief valve
2430-405: A small amount of corrosion inhibitor ). A typical automotive cooling system comprises: The combustion process produces a large amount of heat. If heat were allowed to increase unchecked, detonation would occur, and components outside the engine would fail due to excessive temperature. To combat this effect, coolant is circulated through the engine where it absorbs heat. Once the coolant absorbs
2520-407: Is more difficult to build an aircraft radiator that is able to handle steam, it is by no means impossible. The key requirement is to provide a system that condenses the steam back into liquid before passing it back into the pumps and completing the cooling loop. Such a system can take advantage of the specific heat of vaporization , which in the case of water is five times the specific heat capacity in
2610-411: Is more prone to failure and less easily repaired than traditional materials. An earlier construction method was the honeycomb radiator. Round tubes were swaged into hexagons at their ends, then stacked together and soldered. As they only touched at their ends, this formed what became in effect a solid water tank with many air tubes through it. Some vintage cars use radiator cores made from coiled tube,
2700-410: Is that the fuselage is closer to the ground which eases cargo loading, especially for aircraft with a rear-fuselage cargo door. Military cargo aircraft are predominantly high-wing designs with a rear cargo door. A parasol wing is not directly attached to the fuselage but held above it, supported by either cabane struts or a pylon. Additional bracing may be provided by struts or wires extending from
2790-438: Is that the specific heat capacity changes and boiling point reduces with pressure, and this pressure changes more rapidly with altitude than the drop in temperature. Thus, generally, liquid cooling systems lose capacity as the aircraft climbs. This was a major limit on performance during the 1930s when the introduction of turbosuperchargers first allowed convenient travel at altitudes above 15,000 ft, and cooling design became
Kawasaki Ki-100 - Misplaced Pages Continue
2880-437: Is usually incorporated in the radiator's fill cap. This pressure varies between models, but typically ranges from 4 to 30 psi (30 to 200 kPa). As the coolant system pressure increases with a rise in temperature, it will reach the point where the pressure relief valve allows excess pressure to escape. This will stop when the system temperature stops rising. In the case of an over-filled radiator (or header tank) pressure
2970-434: Is vented by allowing a little liquid to escape. This may simply drain onto the ground or be collected in a vented container which remains at atmospheric pressure. When the engine is switched off, the cooling system cools and liquid level drops. In some cases where excess liquid has been collected in a bottle, this may be 'sucked' back into the main coolant circuit. In other cases, it is not. Before World War II, engine coolant
3060-571: The English Channel in 1909. Throughout 1909–1910, Hubert Latham set multiple altitude records in his Antoinette IV monoplane, eventually reaching 1,384 m (4,541 ft). The equivalent German language term is Eindecker , as in the mid-wing Fokker Eindecker fighter of 1915 which for a time dominated the skies in what became known as the " Fokker scourge ". The German military Idflieg aircraft designation system prior to 1918 prefixed monoplane type designations with an E , until
3150-693: The Fokker D.VIII and Morane-Saulnier AI in the later part of the First World War. A parasol wing also provides a high mounting point for engines and during the interwar period was popular on flying boats, which need to lift the propellers clear of spray. Examples include the Martin M-130 , Dornier Do 18 and the Consolidated PBY Catalina . Compared to a biplane , a parasol wing has less bracing and lower drag. It remains
3240-719: The Ki-61 was one of the best fighters of the Imperial Japanese Army Air Service (IJAAS). It was also the only production Japanese fighter to have an inline powerplant, the V-12 Kawasaki Ha-40 , a Japanese adaptation of the German Daimler-Benz DB 601 engine, as well as one of the first with factory-installed armor and self-sealing fuel tanks . It also had a respectable performance, in line with contemporary American designs, with speed and rate of climb emphasized instead of manoeuvrability and range. It
3330-560: The Mercedes 35hp . It is sometimes necessary for a car to be equipped with a second, or auxiliary, radiator to increase the cooling capacity, when the size of the original radiator cannot be increased. The second radiator is plumbed in series with the main radiator in the circuit. This was the case when the Audi 100 was first turbocharged creating the 200. These are not to be confused with intercoolers . Some engines have an oil cooler,
3420-554: The P-51 Mustang ) derive thrust from it. The thrust was significant enough to offset the drag of the duct the radiator was enclosed in and allowed the aircraft to achieve zero cooling drag. At one point, there were even plans to equip the Supermarine Spitfire with an afterburner , by injecting fuel into the exhaust duct after the radiator and igniting it . Afterburning is achieved by injecting additional fuel into
3510-451: The braced parasol wing became popular on fighter aircraft, although few arrived in time to see combat. It remained popular throughout the 1920s. On flying boats with a shallow hull, a parasol wing allows the engines to be mounted above the spray from the water when taking off and landing. This arrangement was popular on flying boats during the 1930s; a late example being the Consolidated PBY Catalina . It died out when taller hulls became
3600-517: The light aircraft carrier USS Belleau Wood in an air battle where the Ki-100 pilots claimed 12 victories with two losses. Claims and counter-claims for this action remain contentious. The Americans claimed two Ki-100s and admitted to losing two VF-31 F6F-5 Hellcats. These include a Ki-100 and a Hellcat which collided, killing both pilots. After the bombing of the Kagamigahara plant and
3690-725: The 1930s, the cantilever monoplane was fast becoming the standard configuration for a fixed-wing aircraft. Advanced monoplane fighter-aircraft designs were mass-produced for military services around the world in both the Soviet Union and the United States in the early–mid 1930s, with the Polikarpov I-16 and the Boeing P-26 Peashooter respectively. Most military aircraft of WWII were monoplanes, as have been virtually all aircraft since, except for
Kawasaki Ki-100 - Misplaced Pages Continue
3780-652: The Ki-100-Ib, was produced with a cut down rear fuselage during the last months of the war which equipped five home defence sentai . High-altitude performance was further improved with the final variant, the Ki-100-II, however only three of these were produced before the war ended and this final variant never saw operational service. The Ki-100 was a stressed-skin cantilever low-wing single-seat enclosed-cockpit radial engine monoplane fighter with retractable undercarriage. Control surfaces were fabric covered. In mid-1944,
3870-493: The Ki-61 airframe to accept the new engine. Their solution was to use a second skin to form a fairing riveted to the fuselage to smooth out the airflow behind the cooling flaps and multiple exhaust stubs of the new engine cowling . As this engine was lighter, they were able to remove the lead counterweight in the tail that balanced out the heavier Ha-140 engine. The new model was flown for the first time on 1 February 1945. Without
3960-525: The United States, who then shipped them back to the US for evaluation. Note: Not included: Data from Japanese Aircraft of the Pacific War General characteristics Performance Armament Aircraft of comparable role, configuration, and era Related lists Monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to
4050-473: The World War II period used this solution. However, pressurized systems were also more complex, and far more susceptible to damage - as the cooling fluid was under pressure, even minor damage in the cooling system like a single rifle-calibre bullet hole, would cause the liquid to rapidly spray out of the hole. Failures of the cooling systems were, by far, the leading cause of engine failures. Although it
4140-413: The adoption of glycol or water-glycol mixtures. These led to the adoption of glycols for their antifreeze properties. Since the development of aluminium alloy or mixed-metal engines, corrosion inhibition has become even more important than antifreeze, and in all regions and seasons. An overflow tank that runs dry may result in the coolant vaporizing, which can cause localized or general overheating of
4230-481: The aircraft more manoeuvrable, as on the Spitfire ; but aircraft that value stability over manoeuvrability may then need some dihedral . A feature of the low-wing position is its significant ground effect , giving the plane a tendency to float farther before landing. Conversely, this ground effect permits shorter takeoffs. A mid wing is mounted midway up the fuselage. The carry-through spar structure can reduce
4320-555: The aircraft wings, fuselage and even the rudder. Several aircraft were built using their design and set numerous performance records, notably the Heinkel He 119 and Heinkel He 100 . However, these systems required numerous pumps to return the liquid from the spread-out radiators and proved to be extremely difficult to keep running properly, and were much more susceptible to battle damage. Efforts to develop this system had generally been abandoned by 1940. The need for evaporative cooling
4410-525: The approval of the Fokker D.VIII fighter from its former "E.V" designation. However, the success of the Fokker was short-lived, and World War I was dominated by biplanes. Towards the end of the war, the parasol monoplane became popular and successful designs were produced into the 1920s. Nonetheless, relatively few monoplane types were built between 1914 and the late 1920s, compared with the number of biplanes. The reasons for this were primarily practical. With
4500-472: The coolant temperature as the engine warms up. Engine coolant is directed by the thermostat to the inlet of the circulating pump and is returned directly to the engine, bypassing the radiator. Directing water to circulate only through the engine allows the engine to reach optimum operating temperature as quickly as possible whilst avoiding localized "hot spots." Once the coolant reaches the thermostat's activation temperature, it opens, allowing water to flow through
4590-437: The correct clearances. Another side effect of over-cooling is reduced performance of the cabin heater, though in typical cases it still blows air at a considerably higher temperature than ambient. The thermostat is therefore constantly moving throughout its range, responding to changes in vehicle operating load, speed, and external temperature, to keep the engine at its optimum operating temperature. On vintage cars you may find
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#17327717812254680-472: The engine coolant because natural circulation has very low flow rates. A system of valves or baffles, or both, is usually incorporated to simultaneously operate a small radiator inside the vehicle. This small radiator, and the associated blower fan, is called the heater core , and serves to warm the cabin interior. Like the radiator, the heater core acts by removing heat from the engine. For this reason, automotive technicians often advise operators to turn on
4770-459: The engine is producing. Allowing too much flow of coolant to the radiator would result in the engine being over-cooled and operating at lower than optimum temperature, resulting in decreased fuel efficiency and increased exhaust emissions. Furthermore, engine durability, reliability, and longevity are sometimes compromised, if any components (such as the crankshaft bearings) are engineered to take thermal expansion into account to fit together with
4860-410: The engine. Severe damage may result if the vehicle is allowed to run over temperature. Failures such as blown head gaskets, and warped or cracked cylinder heads or cylinder blocks may be the result. Sometimes there will be no warning, because the temperature sensor that provides data for the temperature gauge (either mechanical or electrical) is exposed to water vapor, not the liquid coolant, providing
4950-405: The enormous amount of heat energy soaked up during the generation of steam, equivalent to 500 °C. In effect, the evaporative version is operating between 80 °C and 560 °C, a 480 °C effective temperature difference. Such a system can be effective even with much smaller amounts of water. The downside to the evaporative cooling system is the area of the condensers required to cool
5040-494: The fan unnecessarily. On modern vehicles, further regulation of cooling rate is provided by either variable speed or cycling radiator fans. Electric fans are controlled by a thermostatic switch or the engine control unit . Electric fans also have the advantage of giving good airflow and cooling at low engine revs or when stationary, such as in slow-moving traffic. Before the development of viscous-drive and electric fans, engines were fitted with simple fixed fans that drew air through
5130-464: The fighter relatively stationary in the sights of the bomber's defensive guns, making it an easy target. In this type of combat, the Navy's Mitsubishi J2M Raiden remained superior. 111th Sentai Ki-100s intercepted B-29 Superfortresses attacking Kobe on 5 June 1945, claiming six bombers shot down and five 'probables'. The Americans recorded a loss of nine B-29s, including those downed by Ki-100s over
5220-402: The fuselage sides. The first parasol monoplanes were adaptations of shoulder wing monoplanes, since raising a shoulder mounted wing above the fuselage greatly improved visibility downwards, which was useful for reconnaissance roles, as with the widely used Morane-Saulnier L . The parasol wing allows for an efficient design with good pilot visibility, and was adopted for some fighters such as
5310-433: The general variations in wing configuration such as tail position and use of bracing, the main distinction between types of monoplane is where the wing is mounted vertically on the fuselage . A low wing is one which is located on or near the bottom of the fuselage. Placing the wing low allows good visibility upwards and frees the central fuselage from the wing spar carry-through. By reducing pendulum stability, it makes
5400-681: The hands of an experienced pilot. The Ki-100 along with the Army's Nakajima Ki-84 and the Navy's Kawanishi N1K-J were equal to the latest Allied types in the final year of the Pacific War. Army fighter units equipped with this model included the 5th, 17th, 18th, 20th, 59th, 111th, 112th, 200th and 244th Sentai , and the 81st Independent Fighter Company. Pilots were trained at the Akeno and Hitachi (Mito) Army Flying Schools. Many Akeno and Hitachi instructors were from operational units and between training sorties they also flew combat missions, making
5490-404: The heat from the engine it continues its flow to the radiator. The radiator transfers heat from the coolant to the passing air. Radiators are also used to cool automatic transmission fluids , air conditioner refrigerant , intake air , and sometimes to cool motor oil or power steering fluid . A radiator is typically mounted in a position where it receives airflow from the forward movement of
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#17327717812255580-407: The heater and set it to high if the engine is overheating , to assist the main radiator. The engine temperature on modern cars is primarily controlled by a wax-pellet type of thermostat , a valve that opens once the engine has reached its optimum operating temperature . When the engine is cold, the thermostat is closed except for a small bypass flow so that the thermostat experiences changes to
5670-422: The incoming air charge—not to cool the engine. Aircraft with liquid-cooled piston engines (usually inline engines rather than radial) also require radiators. As airspeed is higher than for cars, these are efficiently cooled in flight, and so do not require large areas or cooling fans. Many high-performance aircraft however suffer extreme overheating problems when idling on the ground - a mere seven minutes for
5760-616: The liquid form. Additional gains may be had by allowing the steam to become superheated. Such systems, known as evaporative coolers , were the topic of considerable research in the 1930s. Consider two cooling systems that are otherwise similar, operating at an ambient air temperature of 20 °C. An all-liquid design might operate between 30 °C and 90 °C, offering 60 °C of temperature difference to carry away heat. An evaporative cooling system might operate between 80 °C and 110 °C. At first glance this appears to be much less temperature difference, but this analysis overlooks
5850-415: The low engine powers and airspeeds available, the wings of a monoplane needed to be large in order to create enough lift while a biplane could have two smaller wings and so be made smaller and lighter. Towards the end of the First World War, the inherent high drag of the biplane was beginning to restrict performance. Engines were not yet powerful enough to make the heavy cantilever-wing monoplane viable, and
5940-492: The most of the few fighters that were operational, but these wings were only partially re-equipped. During interception of high-flying B-29 Superfortresses (before the B-29s switched to low-level missions) the new fighters struggled as the engine's performance still dropped off at high altitudes. The most effective strategy against the B-29 Superfortress remained the exceedingly dangerous head-on attack, which left
6030-470: The need for the heavy coolant radiator and other fittings required for a liquid-cooled engine, the Ki-100 was 329 kg (725 lb) lighter than the Ki-61-II, reducing the wing loading from 189 kg/m (38.8 lb/ft) to 175 kg/m (35.8 lb/ft). This had a positive effect on the flight characteristics, enhancing landing and takeoff qualities as well as improving manoeuvrability and reducing
6120-433: The need to handle gas in the flow greatly complicates design. For a water cooled system, this means that the maximum amount of heat transfer is limited by the specific heat capacity of water and the difference in temperature between ambient and 100 °C. This provides more effective cooling in the winter, or at higher altitudes where the temperatures are low. Another effect that is especially important in aircraft cooling
6210-409: The new engine was much more reliable. Although its maximum speed in level flight was a bit slow for 1945, the Ki-100 could dive with North American P-51 Mustangs and maintain speed after pullout, unlike most Japanese fighters. Two remaining problems continued to hamper Japanese fighters towards the end of the war, these being unreliable electrical systems and poor radio equipment, and while the latter
6300-410: The norm during World War II, allowing a high wing to be attached directly to the hull. As ever-increasing engine powers made the weight of all-metal construction and the cantilever wing more practical — first pioneered together by the revolutionary German Junkers J 1 factory demonstrator in 1915–16 — they became common during the post–World War I period, the day of the braced wing passed, and by
6390-450: The radiator at all times. Vehicles whose design required the installation of a large radiator to cope with heavy work at high temperatures, such as commercial vehicles and tractors would often run cool in cold weather under light loads, even with the presence of a thermostat , as the large radiator and fixed fan caused a rapid and significant drop in coolant temperature as soon as the thermostat opened. This problem can be solved by fitting
6480-431: The radiator to prevent the temperature from rising higher. Once at optimum temperature, the thermostat controls the flow of engine coolant to the radiator so that the engine continues to operate at optimum temperature. Under peak load conditions, such as driving slowly up a steep hill whilst heavily laden on a hot day, the thermostat will be approaching fully open because the engine will be producing near maximum power while
6570-647: The rate of climb, general performance was improved as well. However, it never performed as expected due to continued quality control problems with the engine, while far fewer engines were produced than required. At this point of the war, the IJAAS was in desperate need of effective interceptors to stop bombing raids over the Japanese mainland, so in October 1944 a decision was made to use the 1,120 kW (1,500 hp) Mitsubishi Ha-112 -II ( Kinsei ["Venus"] 60 series),
6660-555: The slow deliveries of components by satellite plants, the production rate of the Ki-100 declined, and between May and July, only 12 were delivered. Bombing ended production with only 118 of the Army Type 5 Fighter Model 1b having been delivered. The final flights made by the Imperial Japanese Army Air Service were made by two Ki-100s ferried from Komachi to Yokosuka , where they were handed over to
6750-509: The steam back below the boiling point. As steam is much less dense than water, a correspondingly larger surface area is needed to provide enough airflow to cool the steam back down. The Rolls-Royce Goshawk design of 1933 used conventional radiator-like condensers and this design proved to be a serious problem for drag. In Germany, the Günter brothers developed an alternative design combining evaporative cooling and surface radiators spread all over
6840-453: The target area. Ki-100s of the same unit joined by 244th Sentai Ki-84s in a large-scale engagement against 21st Fighter Group and 506th Fighter Group P-51 Mustangs over Nagoya Bay on 16 July 1945. The Ki-100 pilots claimed six P-51s and in return, five Ki-100s were lost, with three pilots killed, although American records only show one loss. On 25 July 1945, 18 244th Sentai Ki-100 fighters clashed with 10 VF-31 Grumman F6F Hellcats from
6930-453: The top of the fuselage. It shares many advantages and disadvantages with the shoulder wing, but on a light aircraft, the high wing has poorer upwards visibility. On light aircraft such as the Cessna 152 , the wing is usually located above the cabin, so that the wing spar passes over the occupants' heads, leaving the wing in the ideal fore-aft position. An advantage of the high-wing configuration
7020-606: The turning radius. During March and April 1945, experienced instructors from the Akeno Army Flying School flew the Ki-100 in extensive tests against the Ki-84, which was the best IJAAS fighter then in operational service. Their conclusions were that, given pilots of equal experience, the Ki-100 would always win in combat. The flight characteristics of the plane surpassed the Hien ' s in all but maximum speed, which
7110-439: The useful fuselage volume near its centre of gravity, where space is often in most demand. A shoulder wing (a category between high-wing and mid-wing) is a configuration whereby the wing is mounted near the top of the fuselage but not on the very top. It is so called because it sits on the "shoulder" of the fuselage, rather than on the pilot's shoulder. Shoulder-wings and high-wings share some characteristics, namely: they support
7200-527: The vehicle, such as behind a front grill. Where engines are mid- or rear-mounted, it is common to mount the radiator behind a front grill to achieve sufficient airflow, even though this requires long coolant pipes. Alternatively, the radiator may draw air from the flow over the top of the vehicle or from a side-mounted grill. For long vehicles, such as buses, side airflow is most common for engine and transmission cooling and top airflow most common for air conditioner cooling. Automobile radiators are constructed of
7290-407: The velocity of airflow across the radiator is low. (Being a heat exchanger, the velocity of air flow across the radiator has a major effect on its ability to dissipate heat.) Conversely, when cruising fast downhill on a motorway on a cold night on a light throttle, the thermostat will be nearly closed because the engine is producing little power, and the radiator is able to dissipate much more heat than
7380-447: The water is hotter than the ambient air, its higher thermal conductivity offers comparable cooling (within limits) from a less complex and thus cheaper and more reliable oil cooler. Less commonly, power steering fluid, brake fluid, and other hydraulic fluids may be cooled by an auxiliary radiator on a vehicle. Turbo charged or supercharged engines may have an intercooler , which is an air-to-air or air-to-water radiator used to cool
7470-465: The weight reduction allows it to fly slower and with a lower-powered and more economical engine. For this reason, all monoplane wings in the pioneer era were braced and most were up until the early 1930s. However, the exposed struts or wires create additional drag, lowering aerodynamic efficiency and reducing the maximum speed. High-speed and long-range designs tend to be pure cantilevers, while low-speed short-range types are often given bracing. Besides
7560-518: Was an effective design, but suffered from engine shortages and reliability problems. These problems led to the development of an improved model, the Ki-61-II (later Ki-61-II-KAI ), powered by the improved 1,120 kW (1,500 hp) Kawasaki Ha-140 inverted V-12 engine, which was heavier than the Ha-40 it replaced. Maximum speed increased from 590 to 610 km/h (370 to 380 mph) and aside from
7650-531: Was cut off and a tubular steel engine mount was bolted to the firewall. Some redundant fittings from the liquid-cooled engine, such as the radiator shutter actuator, were left in place. The first 271 aircraft with the original faired rear fuselage were rolled out of the factory between March and June 1945. In contrast to the unreliable engines used by the Kawanishi N1K-J , Kawasaki Ki-61 and Nakajima Ki-84 that were keeping many of these aircraft grounded,
7740-449: Was never resolved, the Ki-100's electrical system was less of a problem than with other types. The armament remained the same as was used on the Ki-61, which was two cowl-mounted 20 mm (0.79 in) calibre Ho-5 cannons , with 200 rounds per gun complemented by two wing-mounted 12.7 mm (0.50 in) Ho-103 machine guns with 250 rounds per gun. The Ki-100-I-Otsu were newly built as such, rather than being conversions, with
7830-462: Was reduced by 29 km/h (18 mph) by the larger cross sectional area of the radial engine, and the model was ordered into production as the Goshikisen ( Go =five; shiki =type; sentoki =fighter) or Army Fighter Type 5 . The company's designation for it was Ki-100-I-Ko . All Ki-100-I-Ko were converted from existing Ki-61-II Kai and Ki-61-III airframes. The integral engine mount and cowling
7920-467: Was soon to be negated by the widespread availability of ethylene glycol based coolants, which had a lower specific heat , but a much higher boiling point than water. An aircraft radiator contained in a duct heats the air passing through, causing the air to expand and gain velocity. This is called the Meredith effect , and high-performance piston aircraft with well-designed low-drag radiators (notably
8010-469: Was used operationally. Due to a lack of space no intercooler was installed; however, performance was still enhanced above 8,000 m (26,000 ft). The Ki-100 made its combat debut on the night of 9 March 1945 and suffered its first loss a month later on the night of 7 April 1945, when a single Ki-100 of the 18th Sentai was downed by a B-29 Superfortress after "attacking the formation again and again". Allied aircrews soon realised that they were facing
8100-417: Was usually plain water. Antifreeze was used solely to control freezing, and this was often only done in cold weather. If plain water is left to freeze in the block of an engine the water can expand as it freezes. This effect can cause severe internal engine damage due to the expanding of the ice. Development in high-performance aircraft engines required improved coolants with higher boiling points, leading to
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