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What version? What supercharger set-up?Thoughts?
Propulsion of F8F-1 and -2.What version? What supercharger set-up?
(a topic better suited for the other sub-forum, IMO)
They used different engines.Propulsion of F8F-1 and -2
All of this assumes that Ki-84 can get at least the 130 grade fuel.Propulsion of F8F-1 and -2.
How would they be compared to the respective Bearcats in flight performance?All of this assumes that Ki-84 can get at least the 130 grade fuel.
Climbing performance would've been far greater than with the Homare, despite the R-2800 being heavier and larger, but to about 5-6 km?. Speed might be better under 5 km, and similar to perhaps 6, and the original being faster above that because there power surplus is now gone, also the climb is better for the legacy Hayate. That is for the case the engine from the -1 is installed.
The engine from the -2 is the E-series R-2800s, and has a much better supercharger. With that, we'd see the performance improvement at all altitudes, and especially above 3-4 km.
Could the Ki-84 airframe have taken the R-2800 anyway?
Counter-balance weights and structural reinforcements should be doable.Installing a heavier but shorter radial engine instead of a lighter but longer V12 does not require a radical change to the airframe, as the center of gravity can be maintained. However, installing the same radial engine, only much heavier, without radically redesigning the airframe is unlikely to be possible. In addition, a more powerful engine may require a propeller with a larger diameter, which would require changing the height of the landing gear struts, which is also unlikely to be possible without a radical redesign of the airframe.
The M-71 was exactly 100 kg heavier than the M-82F, and this difference could still be compensated without significant modification of the airframe, whereas the R-2800 exceeded the weight of the Ha-45 by more than 250 kg.
In my humble opinion, redesigning the airframe for the R-2800 would result in the development of a completely new aircraft.
The first option means unnecessary weight increase, while the second results in a complete redesign of the entire airframe. The landing gear will need to be reinforced, etc. Finally, it will be easier to design a new aircraft.Counter-balance weights and structural reinforcements should be doable.
Perhaps. But apparently not always - for example, the attempt to install the M-82 on the Yak failed due to the need to use a larger diameter propeller. This required longer landing gear struts, which led to significant design changes that Yakovlev categorically refused to make. And with a smaller propeller diameter, the performance was lower than with the less powerful M-105. Perhaps this was a purely Soviet problem - the low technological level did not allow the Soviets to mass-produce propellers with broader blades during the war (propellers with broad blades were used only on a few prototypes of high-altitude fighters). It can be assumed that the Japanese aviation industry may have experienced similar difficulties.Propeller surface area can be increased with broader blades.
If weight increase of a Hayate with a 2800 would be about 500 kg as a rough estimate (someone correct me if necessary), it would weigh as much as an Fw 190D-12 but with almost 3 sqm more wing area.The first option means unnecessary weight increase, while the second results in a complete redesign of the entire airframe. The landing gear will need to be reinforced, etc. Finally, it will be easier to design a new aircraft.
Perhaps. But apparently not always - for example, the attempt to install the M-82 on the Yak failed due to the need to use a larger diameter propeller. This required longer landing gear struts, which led to significant design changes that Yakovlev categorically refused to make. And with a smaller propeller diameter, the performance was lower than with the less powerful M-105. Perhaps this was a purely Soviet problem - the low technological level did not allow the Soviets to mass-produce propellers with broader blades during the war (propellers with broad blades were used only on a few prototypes of high-altitude fighters). It can be assumed that the Japanese aviation industry may have experienced similar difficulties.
What should Pratt and Whitney charge Nakajima per engine?Thoughts?
I don't really know how much the Ki-84-N project differed from the production Ki-84, except that the wing area was 1.5 square meters larger, but the Ha219 was ~80 kg heavier than the R-2800. I might be overestimating the problems caused by the increased engine weight. However, the difference in the ratio of engine weight to airframe weight is quite significant: ~42% for the Ki-84 (810 / 1890) and ~50% for the hypothetical Ki-84-R2800 (1070 / 2130), considering that the production Ki-84 had problems with the strength of the landing gear struts, it is difficult to imagine how it would have been possible to install a much heavier engine without significantly redesigning the entire structure.If weight increase of a Hayate with a 2800 would be about 500 kg as a rough estimate (someone correct me if necessary), it would weigh as much as an Fw 190D-12 with almost 3 sqm more wing area.
This does not mean that Japan would be able to follow the same way.The Germans went the way with broader blades successfully.
An R2800 powered Ki.84 would be bigger and heavier than a Nakajima Homare powered Ki.84. It would be faster. Given Japanese design practise, it would have better acceleration and climb, and would be a bit less manoeuverable. The Ki.84 was reasonably well armed. The extra power would allow better armour protection.Thoughts?
Infrequently.Thoughts?