Jet Power Comparison

[Lord_Cool]

A quick comparison and rough approximation of the power of the gas turbines in the jets we might see in IL-2 Korea. Not that it’s particularly useful, just out of interest.

 

For static, sea-level standard (SLS) conditions. Maximum dry thrust only, not with any water injection. Taking into account mass flow and exhaust velocity (derived from the specific thrust)

 

Klimov VK-1 (MiG-15bis) (assuming 2700kgf (5952lbf) thrust, 48.2kg/s (106.3lb/s) mass flow) - 9753 hp

(Another source gives 45 kg/s (99.2 lb/s) for mass flow)

 

Allison J35-A-29 (F84G) (assuming 2522kgf (5560lbf) thrust, 43.1kg/s (95lb/s) mass flow) - 9519 hp

 

General Electric J47-GE-13 (F86A) (assuming 2359kgf (5200lbf) thrust, 42 kg/s (92.6lb/s) mass flow) - 8542 hp

 

Allison J33-A-35 (F80C) (assuming 2087kgf (4600lbf) thrust, 40.8kg/s (90lb/s) mass flow) - 6877 hp

 

For reference -

 

Jumo 004-B1(Me262 A/Ar 234 B-2) (assuming 900kgf (1984lbf) thrust, 21.2kg/s (46.7lb/s) mass flow) - 2464 hp

(although the IL-2 reference gives 810kgf?)

 

Will be interested to hear how these sound in game. I’d expect them to be louder and slightly more ‘thunderous’ than the Jumo 004-B1 engines in IL-2 GB series, given the higher exhaust velocities and larger mass flow, but obviously not to the extent of the later and larger PW J57, GE J79, Allison J71 etc.

[FeuerFliegen]

I always wondered how thrust figures compared to hp in a piston engine prop plane.  Thanks for the info!

[Duckman]

Interesting. It's worth bearing in mind that most early jets are bigger and heavier than even the biggest WWII fighters. For example the F-86 and F-84 have an empty weight of 5 tons compared to 3,5 tons for the P-51 and 4,5 tons for the huge P-47.

 

Many WWII aircraft are puny in comparison, like the Spit V at 2,3 tons. The Me-262 weighed in at 3,8 tons.

Edited October 1, 2024 by Duckman

[Lord_Cool]

The J47 compared in the first post was an early variant that was in the F86A, being compared to a later, more developed version of the J35 that was in the F84G, so that's why it comes out as 'less powerful' than the J35. The General Electric J47 is a more advanced engine I believe, being a development of the earlier J35 (also originally a General Electric design but production and responsibility was transferred to Allison in 1947).

 

A later variant of the J47 that as was used in the F86F:

 

General Electric J47-GE-27 (F86F) 2708kgf (5970lbf) dry (and assuming 42kg/s (92.6lb/s) mass flow) then ~ 11250 hp

 

 

Edited October 1, 2024 by Lord_Cool

[MaxPower]

I think there's another way to do this as well.  You can use thrust and aircraft speed to get the 'power available'.  The horsepower varies with jet aircraft speed because moving the aircraft is the work that's being done.  In this way, the amount of horsepower a jet has increases as the aircraft gets faster.  By contrast, reciprocating engines have a relatively constant horsepower but varying thrust.  In this case, thrust decreases quite a bit as an aircraft with a piston engine gets faster.

Anyway, I did some cheap calculations for the General Electric J47-GE-13 as installed in the F-86A at its top seed of 607 mph and I got 9291 horsepower, not too far off from what you got with your static calculation