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That's why the belly-radiator didn't work on all aircraft?The P-40 did not need a boundary layer splitter - there was little or no boundary layer at that point, as the radiator intake was right behind the spinner.
I never saw the radiator up close like this before, but I get it.The P-38 did, albeit a duct rather than a splitter.
I'm curious if it would have been possible to extend the radiator a bit forward like the XP-40Q?[/QUOTE]And the P-39 had flaps to control the mass flow through the radiator
I'm curious if it would have been possible to extend the radiator a bit forward like the XP-40Q?
The P-63 or F4U arrangement could work. Something like the De Havilland Mosquito or Hornet could work as well.Like on the P-63?
Those didn't seem to work out too good, though I do remember seeing three movable doors on the underside of your model, and a small radiator could cover that.Or would you rather some underwing radiators like on the Aeobonita?
I am not sure the problem was heat transfer from the turbine section to the compressor section.
P-47 turbo:
There seems to be a heat shield / cooling duct between the Turbine casing and the compressor casing. Granted some heat could still get through and some be conducted along the shaft.
Only gone through a couple of websites in the Mercedes F1 so I may be reading something wrong but it appears the Turbine drives a generator that feeds a battery pack. The supercharger is electric powered? Battery pack also feeds power to electric motors in rear wheels upon demand (under braking wheel motors act as generators to feed electricity back into the battery)
Haven't found the boost level yet but would bet dollars to donuts that the F1 engine is running higher pressure than the P-47 turbo alone.
In the case of the Mercedes F1 engines of today, the compressor is far removed from exhaust heat and the cooling is much superior to regular turbochargers. They rather obviously haven't made public how much less intercooling is required, but that engine is making an easy 50 - 80 Hp more than others. Most of the non-Mercedes F1 engines are making some 820 Hp while the Mercedes, with the same displacement, is making 870+ HP, and quite reliably. That's 6 to 7.9% more power with no other obvious technology changes. In a 2,000 HP engine, that might give 120 - 158 more HP for free. While not exactly earth-shaking, more it is better.
Somewhere along the way, it was mentioned that the intakes had issues flowing around the tight kinks produced by the landing-gear door positions. So I figured...shortround said:I am not sure what you are trying to accomplish?
Of course, there was no secondary stage of supercharging and no cooler needed as a result.The cooling problems were fixed on the XB-39B and YP-39As.
Okay, so the center was the oil-cooler, and the left and right were the radiators?There were two radiators and one oil cooler.
I never realized friction would have been factored seperately, I figure anything needed to drive the supercharger would be weighted against the extra horsepower produced...P-63 needed bigger ducts, more cooling for several reasons. One is that while the P-39 set up not only worked for the initial 1090hp engine it was able to work for the later 1200-1325hp engines, of course they only made big power down low where the air is dense so mass airflow through the system wasn't too big a problem. Also the single stage engines only used up about 100hp in friction and about 200hp to drive the supercharger so total cooling load was about 1500-1600hp in the cylinders.
What reduces the cooling-air requirements and space requirements?Please note that for inter-coolers to be effective they need 2-3 (or more) times the amount of cooling air as intake for the engine. In other words, even a a well designed system is going to need a scoop 2-3 times the size of the scoop behind the canopy of the of the P-39 or P-63.
How did they get around it?Turbos had their own cooling problems which is why every production installation except the P-47 had them hanging part way out of the airplane.
I understand that, admittedly it's mostly from a knowledge of jet-engines, but...You have to keep the turbine blades from getting so hot that they fail.
I thought that was simply so the exhaust would be reasonably smooth through the turbine, but I had no idea of the use of armor plates to catch the turbine so the pilot wouldn't get skewered.There was a reason that they were placed a number of feet from the engine (exhaust could cool a little) and still had pieces of steel plate to catch/deflect thrown turbine blades from hitting aircrew.
Somewhere along the way, it was mentioned that the intakes had issues flowing around the tight kinks produced by the landing-gear door positions. So I figured...
Of course, there was no secondary stage of supercharging and no cooler needed as a result.
I was in error, Tomo is correct. One square or rectangular radiator in the center and a round oil cooler to either side in their own ducts.Okay, so the center was the oil-cooler, and the left and right were the radiators?
I never realized friction would have been factored seperately, I figure anything needed to drive the supercharger would be weighted against the extra horsepower produced...
Nothing unless you can repeal the laws of physics. You can sometimes do a better job of packaging but please remember that every bend in the ducts and every change in the cross section of the ducts can bring their own losses so you can't just jam everything in tighter. B-17s actually had slightly different full throttle heights on inner and outer engines due to differences in the duct work. Same engines, same turbo, same intercooler.What reduces the cooling-air requirements and space requirements?
How did they get around it?
Which was due to thee more powerful engine?tomo pauk said:The P-39 have had two oil coolers/radiators, and one coolant radiator. P-63 was with two oil coolers/radiators and two coolant radiators.
What about surface evaporative cooling for the engine and a normal radiator for the intercoolerWell you can't have everything
How much drag would you say would present?You want the turbo and intercooler you accept the weight and drag and the poorer performance at 15,000 and below.
15,000 to 20,000 feet being about the same seems acceptable, and much of the performance advantages the USAAF had demonstrated over the Luftwaffe were over 22,000 feet...Turbo only shows real advantage at 20,000ft and up with the 15-20,000ft area being a toss-up/crossover.
How does the radiator size scale in proportion to these figures (i.e. hp to square or cubic inch).When figuring out the size of the radiators/oil coolers you need to find out what the power being produced in cylinders was, not the power going to the propshaft. Friction changed from about 100hp in the early C series engines (long nose) to around 200hp in the late engines that made 1600hp and up in WER mode.
I never knew that...B-17s actually had slightly different full throttle heights on inner and outer engines due to differences in the duct work. Same engines, same turbo, same intercooler.
I was thinking about the inter-cooler, and I was wondering: Did the US ever use liquid cooling for this purpose other than the Merlin 60's?P-47 used a big enough air intake to be able to split off some air to cool the turbo.
I was thinking about the inter-cooler, and I was wondering: Did the US ever use liquid cooling for this purpose other than the Merlin 60's?
Surface cooling only worked for racing planes. It generally required a lot of maintenance to deal with leaks let alone enemy fire.What about surface evaporative cooling for the engine and a normal radiator for the intercooler?
the two mock ups Bell tried with add on turbos were 30-40mph slower than standard P-39s at low altitude. Even cutting that to 20mph with a lot of attention to detail leaves the P-39 with little speed advantage at low altitude over the Zero.How much drag would you say would present?
It doesn't because not all radiators were the same depth front to back, and not all designers used the same pressure drop through the radiator.How does the radiator size scale in proportion to these figures (i.e. hp to square or cubic inch).
Not on service aircraft, not sure about prototypes. Liquid cooling helps with packaging, it is a lot easier to run a few fluid filled lines than large air ducts. It doesn't help so much with actual heat dissipation. Instead of cooling air flowing through inter-cooler with hot air in the alternate passages you replace it with water/antifreeze. Yes the intecooler may be able to be made smaller but now you need the intercooler radiator and you need XXX number of pounds per minute of cooling air to cool the inter-cooler fluid.I was thinking about the inter-cooler, and I was wondering: Did the US ever use liquid cooling for this purpose other than the Merlin 60's?
Surface cooling only worked for racing planes. It generally required a lot of maintenance to deal with leaks let alone enemy fire.
the two mock ups Bell tried with add on turbos were 30-40mph slower than standard P-39s at low altitude. Even cutting that to 20mph with a lot of attention to detail leaves the P-39 with little speed advantage at low altitude over the Zero.
It doesn't because not all radiators were the same depth front to back, and not all designers used the same pressure drop through the radiator.
Not on service aircraft, not sure about prototypes. Liquid cooling helps with packaging, it is a lot easier to run a few fluid filled lines than large air ducts. It doesn't help so much with actual heat dissipation. Instead of cooling air flowing through inter-cooler with hot air in the alternate passages you replace it with water/antifreeze. Yes the intecooler may be able to be made smaller but now you need the intercooler radiator and you need XXX number of pounds per minute of cooling air to cool the inter-cooler fluid.