Двигатель Junkers Jumo 213: Разработка и Усовершенствования

WW2 Aircraft Engine

The Junkers Jumo 213 was a World War II era V 12 liquid cooled aircraft engine, a development of Junkers Motoren's earlier design, the Jumo 211. The design added two features, a pressurized cooling system that required considerably less cooling fluid which allowed the engine to be built smaller and lighter, and a number of improvements that allowed it to run at higher RPM. These changes boosted power by over 500 hp and made the 213 one of the most sought after Axis engine designs in the late war era.

When the Jumo 211 entered production in the late 1930s it used an unpressurized liquid cooling system based on an "open cycle". Water was pumped through the engine to keep it cool, but the system operated at atmospheric pressure, or only slightly higher. Since the boiling point of water decreases with altitude (pressure) this meant that the temperature of the cooling water had to be kept quite low to avoid boiling at high altitudes, which in turn meant that the water removed less heat from the engine before flowing into the radiator to cool it. By contrast, the 1940 Daimler Benz DB 601E used a pressurized coolant system that ran at the same pressure regardless of altitude, raising the boiling point to about 110 °C. This allowed it to use considerably less water for the same cooling effect, which remained the same at all altitudes. Although otherwise similar to the Jumo 211 in most respects, the 601 was smaller and lighter than the 211, and could be run at higher power settings at higher altitudes, making it popular in fighter designs. The 211 was relegated to "secondary" roles in bombers and transports. The Junkers Motorenwerke firm was not happy with this state of affairs, and started its own efforts to produce a pressurized cooling system as early as 1938. Experiments on the 211 proved so successful that it became clear that not only could the engine be built smaller and lighter (by reducing the water requirement), but could be run at higher power settings without overheating. Additional changes to strengthen the crankshaft and add a fully shrouded supercharger for increased boost resulted in the Jumo 211F model, which delivered 1,340 PS (1,322 hp, 986 kW) at 2,600 RPM, up from 1000 PS at 2,200 RPM in the first version 211A.

But this was only the beginning. After redesigning the engine block to a smaller external size to suit the increased cooling power – while keeping the same 150 mm x 165 mm bore/stroke figures, maintaining the 35 litre displacement of the Jumo 211 series – and then further increasing boost settings on the supercharger, the resulting 213A model was able to deliver 1,750 PS (metric hp) at 3,250 RPM. This made it considerably more powerful than the corresponding DB 601E which provided 1,350 PS, and about the same power as the much larger DB 603 of 44.52 litre displacement. Junkers decided to go after the 603's market, and placed the 213's mounting points and fluid connections in the same locations as the 603, allowing it to be "dropped in" as a replacement, with the exception of the Jumo's standard starboard side supercharger intake (Daimler Benz inverted V12 engines always had the supercharger intakes on the port side). The 213A (the main production series, with single stage two speed supercharging) first ran in 1940, but experienced lengthy delays before finally being declared "production quality" in 1943. Production was extremely slow to ramp up, in order to avoid delays in the existing Jumo 211 production. By the time the engines were available in any sort of number in 1944, Allied bombing repeatedly destroyed the production lines. Production of the A model was limited to about 400–500 a month for most of 1944/45.

A range of advanced versions were also developed during the lengthy teething period. The 213B was designed to run on 100 octane "C3" fuel, allowing the boost pressure to be increased and the take off power improved to 2,000 PS. The 213C was essentially an A model with re arranged secondary equipment (supercharger, oil pump, etc.) to allow a Motorkanone cannon to fire through the propeller shaft. The 213D added a new three speed supercharger for smoother power curves and improved altitude performance, but it was not produced. The next major production versions were the 213E and the similar 213F. These engines were equipped with a new two speed, two stage supercharger that dramatically improved altitude performance. The only difference between the two models was that the E included an intercooler Rated at take off power and at rated height. Arsenal 24H Tandem2x 24H engines in tandem driving co axial propellers. SFECMAS 12H The Arsenal 12H after SFECMAS absorbed Arsenal. SFECMAS 12K The Arsenal 12K after SFECMAS absorbed Arsenal.