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Number wise (if we asume engineer estimate of XP-72 is correct), then it is the one with highest rate of climb. Even higher than XP-51GIt's heavy and can't climb like the others, any good pilot facing the Jug will go into a vertical fight and get above it, the Spitfire and Ta 152 would defiantly do a climbing turn then reverse and boom and zoom it.
It's not good to assume, I'd like to see hard evidence on the XP-72 instead of theoretical. It's a heavy aircraft.Number wise (if we asume engineer estimate of XP-72 is correct), then it is the one with highest rate of climb. Even higher than XP-51G
Spiteful: 4890 ft/min (24.8 m/s) at 2000 ft. No additional information
XP-72 with twin props: 5250 ft/min (26.67 m/s) at sea level, take 3.8 min to climb to 20,000 ft
P-51H: 5120 ft/min (26 m/s) at sea level, take 4.58 min to climb to 20,000 ft
XP-51G: take 3.58 min to climb to 20,000 ft
F4U-5: 4840 ft/min (24.58 m/s) at sea level, take 4.7 min to climb to 20,000 ft
A little OT but I never understood why the P-47 air intake was at the front of the plane requiring all that bulky ductwork underneath the pilot? The air is first "used" in the turbocharger behind the pilot so why not a scoop at rear similar to the Mustang radiator?The exhaust pipe is tiny compared to the intake air system. Look at the following diagram.
Not much space is freed
Picture a B50 nacelle with a pilot stuck on topA little OT but I never understood why the P-47 air intake was at the front of the plane requiring all that bulky ductwork underneath the pilot? The air is first "used" in the turbocharger behind the pilot so why not a scoop at rear similar to the Mustang radiator?
As shown in post #26 the intake was moved back a bit on the XP-72 but still underneath the pilot rather than behind (I don't think the mechanical 2nd stage vs the turbo should make any difference, that only replaces exhaust ducting with a driveshaft).
From this thread perhaps a rear intake would suck up too much dust etc (presumably engines are more sensitive than radiators)?
Not at all! Highly compact and weight efficient turbo installations (the V-1710H or Bell's turbosupercharged P-63 are good examples) that could fit a Spitfire or P-51 were very feasible even in 1940. The problem was no one firm had all the knowledge or resources necessary to accomplish this at that time. The USAAF had far to few eggs in far to many baskets nor was the US procurement system really set up to deal with component R&D.Basically the argument is that the USAAF was barking up the wrong tree with turbochargers particularly for fighters. The USN certainly preferred mechanically driven 2 stage superchargers and I think the success of the 2 stage Merlin opened up a lot of eyes. I find it ironic that the P 47 found its niche at low level where a turbocharger is less effective
Picture a B50 nacelle with a pilot stuck on top
I would Republic had learned more about boundary/ram air. There's a progression from P-43 Lancer have slightly ovoid cowl with intake at bottom, to P-47B thru D enlarged ovoid with both intake and intercooler air. Then for the XP-47H, you have the air intakes on the rear fuselage* and the cooling air intake slightly back from propeller.View attachment 796286
The intake position looks fairly similar to the XP-72 but not sure what point you are trying to make?
What I'm wondering is, seeing as the pilot on both P-47 and XP-72 was in between the engine and 2nd stage turbo/supercharger + intercooler, why the intake was not moved back (relative to the engine) along with those accessories? Only reason I can think of is it would ingest too much crud on takeoff? (Probably less of a problem on a B-50 since it's operating on paved runways and the engine is further off the ground.)
Really? Where? It looks very similar to the XP-72 to me. Уголок неба ¦ Republic P-47H Thunderbolt... Then for the XP-47H, you have the air intakes on the rear fuselage*
Slower compared to what? Not having scoops and just having holes flush with the skin in the same place (less drag but less power)? Sort of like the exhausts below the scoops but turned around?*P-47H is interesting: When Republic installed the intake scoops, the engine could get enough air to make full power; but the drag of the scoop resulted in plane being slower...
The 2 "little" scoops are larger combined than single one on say Bf.109 which powered ~1,500 DB engine..Really? Where? It looks very similar to the XP-72 to me. Уголок неба ¦ Republic P-47H Thunderbolt
Do you mean those two little scoops on the upper rear fuselage either side of the "razorback" behind the canopy? They seem so small.
Slower compared to what? Not having scoops and just having holes flush with the skin in the same place (less drag but less power)? Sort of like the exhausts below the scoops but turned around?
Two factors.A little OT but I never understood why the P-47 air intake was at the front of the plane requiring all that bulky ductwork underneath the pilot? The air is first "used" in the turbocharger behind the pilot so why not a scoop at rear similar to the Mustang radiator?
As shown in post #26 the intake was moved back a bit on the XP-72 but still underneath the pilot rather than behind (I don't think the mechanical 2nd stage vs the turbo should make any difference, that only replaces exhaust ducting with a driveshaft).
From this thread perhaps a rear intake would suck up too much dust etc (presumably engines are more sensitive than radiators)?
I would like to learn more about the V-1710H, as well as about the turbocharged P-63, as well as how that was feasible in 1940.Not at all! Highly compact and weight efficient turbo installations (the V-1710H or Bell's turbosupercharged P-63 are good examples) that could fit a Spitfire or P-51 were very feasible even in 1940.
Even before the 60 series Merlin was a success P&W had the same arrangement on the XH-2600 and XH-3130. There really wasn't anything novel or eye opening about it. It was the fastest, simplest and cheapest way to improve performance and given the situation at the time it was unquestionably the right call.
Time machine.I would like to learn more about the V-1710H, as well as about the turbocharged P-63, as well as how that was feasible in 1940.
Bell couldn't come up with a compact and highly efficient turbo installation in 1940 that actually worked.Not at all! Highly compact and weight efficient turbo installations (the V-1710H or Bell's turbosupercharged P-63 are good examples) that could fit a Spitfire or P-51 were very feasible even in 1940.
To visualize what substituting a turbocharger for a mechanical drive would due to the installationView attachment 796286
The intake position looks fairly similar to the XP-72 but not sure what point you are trying to make?
What I'm wondering is, seeing as the pilot on both P-47 and XP-72 was in between the engine and 2nd stage turbo/supercharger + intercooler, why the intake was not moved back (relative to the engine) along with those accessories? Only reason I can think of is it would ingest too much crud on takeoff? (Probably less of a problem on a B-50 since it's operating on paved runways and the engine is further off the ground.)
Shortround6 described the V-1710H. Bell had a P-63 proposal for Wright turbo mounted behind the engine at ~60° from horizontal. Both of these fit in the same space as the regular V-1710 two stage.I would like to learn more about the V-1710H, as well as about the turbocharged P-63, as well as how that was feasible in 1940.
The XH-2600 engine X-95 This engine had two 13in diameter impellers. The first stage had an eye diameter of 9.625 and a van height of 3in. 8.25in and 1.25 for the second stage.Care to elaborate about the 2-stage superchargers as designed for these P&W engines?