Hawker Tempest Mk.II & Bristol Centaurus Questions

[Zipper730]

The Tempest Mk.II seemed to have greater performance than the Tempest Mk.V with seemingly greater speeds across the board and increased climb-rates: What I could use is a graph which depicts

• TAS vs Altitude with the power settings used
• Rate of Climb vs Engine Power and Altitude.

While I'm aware of the very basic details of the Bristol Centaurus in that I know the Centaurus V was used in the aircraft, it had a two-speed supercharger, and that depending on fuel, it could run on +8 to +12 yielding horsepower figures of 2300-2650 in MS, and 1950 in FS with +8: What I could use is information regarding some clarity on engine performance

• Did the RAF have sufficient resources of high-octane fuel to permit the use of +12 on a routine basis
• Could +12 be used in FS gear?

 

[AMCKen]

While I'm aware of the very basic details of the Bristol Centaurus in that I know the Centaurus V was used in the aircraft, it had a two-speed supercharger, and that depending on fuel, it could run on boost levels of +8" to +12" yielding horsepower figures of 2300-2650 in MS, and 1950 in FS with +8": What I could use is information regarding some clarity on engine performance

• Did the RAF have sufficient resources of high-octane fuel to permit the use of +12" on a routine basis
• Could +12" be used in FS gear?

[/QUOTE]

I expect you actually mean +8 or +12 psi (pounds), not inches. 8 = 46.2 inches, 12 = 54.4 inches.

 

[Zipper730]

I expect you actually mean +8 or +12 psi (pounds), not inches. 8 = 46.2 inches, 12 = 54.4 inches.

Yup!

 

[wuzak]

The Tempest Mk.II seemed to have greater performance than the Tempest Mk.V with seemingly greater speeds across the board and increased climb-rates: What I could use is a graph which depicts

• TAS vs Altitude with the power settings used
• Rate of Climb vs Engine Power and Altitude.

While I'm aware of the very basic details of the Bristol Centaurus in that I know the Centaurus V was used in the aircraft, it had a two-speed supercharger, and that depending on fuel, it could run on +8 to +12 yielding horsepower figures of 2300-2650 in MS, and 1950 in FS with +8: What I could use is information regarding some clarity on engine performance

• Did the RAF have sufficient resources of high-octane fuel to permit the use of +12 on a routine basis
• Could +12 be used in FS gear?

did you look at WWII Aircraft Performance?

 

[Shortround6]

Did the RAF have sufficient resources of high-octane fuel to permit the use of +12 on a routine basis

The Centaurus would run perfectly fine at 12lbs boost on 100/130 fuel. I have never heard of the RAF being short of 100/130 fuel near the end of the war or postwar.

 

[Zipper730]

Even in FS?

 

[Shortround6]

Even in FS?

See: http://www.wwiiaircraftperformance.org/tempest/tempestii-cfe-appd.jpg

 

[Zipper730]

See: http://www.wwiiaircraftperformance.org/tempest/tempestii-cfe-appd.jpg

The only horsepower figures I got for FS was +8...

Is there anyway to compute figures for +12

 

[Neil Stirling]

Bristol Centaurus power chart March 1945.
Public Record Office Kew. AVIA 15/2911.

Neil.

 

[Zipper730]

I'm looking in a document on the Sea Fury Mk.11 and max continuous is 6-1/2", maximum listed is 9-1/2". Did the RN:FAA have access to different octane fuel levels, or was this a peacetime setting?

What was the wartime normal power rating in pressure and horsepower?

 

[Neil Stirling]

Intended http://www.wwiiaircraftperformance.org/Fury/Sea_Fury_Flight.pdf and would of required 150 grade fuel. The Aeroplane magazine of 1946 gives 2,780hp at 3,000ft with this performance. No it doesn't give power in F.S.

Post war http://www.wwiiaircraftperformance.org/Fury/Sea_Fury_Flight.pdf

No need to thrash the engine given the lack of opposition. Many aircraft post war ran lower boost than was possible.

Neil.

 

[Zipper730]

Intended http://www.wwiiaircraftperformance.org/Fury/Sea_Fury_Flight.pdf and would of required 150 grade fuel. The Aeroplane magazine of 1946 gives 2,780hp at 3,000ft with this performance. No it doesn't give power in F.S.

Lots of power

No need to thrash the engine given the lack of opposition. Many aircraft post war ran lower boost than was possible.

But the normal setting was still +6.5 or higher?

 

[Neil Stirling]

Lots of power
But the normal setting was still +6.5 or higher?

Sorry no info, I would guess it would be 6.5 lbs boost.

Neil.

 

[Zipper730]

Sorry no info, I would guess it would be 6.5 lbs boost.

Is there anyway to correlate PSI or Inches HG to horsepower?

 

[pbehn]

Is there anyway to correlate PSI or Inches HG to horsepower?

Try it with a Merlin.

 

[Shortround6]

Is there anyway to correlate PSI or Inches HG to horsepower?

Only for one engine, and only for one supercharger gear and only for one altitude and only for one airspeed and only for........

Please note the constant rpm and constant airspeed. Below the peaks (to the left) the pressure is constant yet power varies until throttle is fully opened.
Difference between high and low gear is the power needed to run the supercharger and the fact that the air is less dense due to the higher temperature even if the pressure is the same.

 

[Zipper730]

Centaurus V,VI,VIII,IX,X & XI

Boost.....Fuel..........Horsepower (No Ram)
...............................M/S..................................F/S..............................Notes
+8-1/2....100/130....2520 bhp @ 1000'...........2225 bhp @ 11000'....
+10........100/130....2700 bhp @ 0' (+9-1/2)...,,2450 bhp @ 9250'......Water Injection
+12........100/150....2570 bhp @ 0' (+9-1/2).....2500 bhp @ 6500'......
+16........100/150....2700 bhp @ 0' (+9-1/2).....2880 bhp @ 1750'......Water Injection

Boost.....Fuel..........Horsepower (Ram)..............................................Notes
...............................M/S...................................F/S
+8-1/2....100/130....2500 bhp @ 5250'............2200 bhp @ 15250'
+10........100/130....2755 bhp @ 2750'............2415 bhp @ 13000'....Water Injection
+12........100/150....2730 bhp @ 0'..................2475 bhp @ 11750'
+16........100/150....2950 bhp @ 0' (+12-1/2)....2850 bhp @ 6000'......Water Injection

If the + 6.5" figure is the same on the wartime settings that would yield 2160 and 2100 in MS/FS gear...

 

[Tzigy]

I an having a very difficult time finding what M and S designation for the SC gear/ratios stand for...can anyone help me? Nvm, got it. Moderate and High/Supercharged