Seems like there were at least two problems to iron out before we start blaming the propellers. And far easier to pinpoint.
Very true.
German Schenellbombers - were there any?
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Seems like there were at least two problems to iron out before we start blaming the propellers. And far easier to pinpoint.I am just an old firefighter but with water putting kinks and turns in hoses/pipes can lead to a lot of pressure/flow losses.
I imagine that air is the same. The Allison P-40 and P-51s had a really nice intake, Long and smooth with one roughly 90 degree turn into the carb.
109 used one 90 degree bend, Early Spitfire used one 90 degree bend
Some of the "using an intake in the leading edge of the wing" may look nice but how many twists and turns does it make getting to the carb?
How many 90 degree bends in the Whirlwind intake? at least two? maybe more but shallower bends?
The supercharger multiplies the inlet pressure so just a small drop is a significant change near or above critical altitude.
Whirlwind exhaust was pretty terrible also from a thrust stand point. Might have been good for flame suppression?
Very true.An improved Whirlwind, and Spitfire Mk. III's. Now THERE is a What If scenario for 1940!
German Schenellbombers - were there any?It would still struggle to intercept the German Schnellbombers
I wonder what the Blenheim would do with a pair of Peregrines or early Merlins, both with chin rads.
(my bold)A Schnell bomber can be its own worst enemy unless the speed is sufficient to protect it and it can make more effective precision attacks than the standard model bomber.
Someone should have told de Havilland that "using an intake in the leading edge of the wing" just looked nice and that the Hornet wouldn't be fast as a result. (Probably the same for Grumman with the F7F Tigercat, Vought F4U Corsair and a few others).I am just an old firefighter but with water putting kinks and turns in hoses/pipes can lead to a lot of pressure/flow losses.
I imagine that air is the same. The Allison P-40 and P-51s had a really nice intake, Long and smooth with one roughly 90 degree turn into the carb.
109 used one 90 degree bend, Early Spitfire used one 90 degree bend
Some of the "using an intake in the leading edge of the wing" may look nice but how many twists and turns does it make getting to the carb?
How many 90 degree bends in the Whirlwind intake? at least two? maybe more but shallower bends?
The supercharger multiplies the inlet pressure so just a small drop is a significant change near or above critical altitude.
Whirlwind exhaust was pretty terrible also from a thrust stand point. Might have been good for flame suppression?
I am just an old firefighter but with water putting kinks and turns in hoses/pipes can lead to a lot of pressure/flow losses.
I imagine that air is the same. The Allison P-40 and P-51s had a really nice intake, Long and smooth with one roughly 90 degree turn into the carb.
109 used one 90 degree bend, Early Spitfire used one 90 degree bend
Some of the "using an intake in the leading edge of the wing" may look nice but how many twists and turns does it make getting to the carb?
How many 90 degree bends in the Whirlwind intake? at least two? maybe more but shallower bends?
The supercharger multiplies the inlet pressure so just a small drop is a significant change near or above critical altitude.
Whirlwind exhaust was pretty terrible also from a thrust stand point. Might have been good for flame suppression?
The later C-47s (and a number of other radial engines) had sand filters installed at the rear of the inlet, the actual air inlet curved down a little earlier. The solid particles tended to go straighter and go through the curved slats at the sharp bend to the outside of the actual intake tract. There were different designs, sometimes the dirt trap was in front(?) like Martin Baltimores? Some P-38s had two inlets. The normal one on the outside of the cowl and an inner one with a filter that drew from the landing gear well. Obviously only used for take-off and landing but that is when dust/dirt was the worst.In general yes but there are some "strange" caveats. The early DC-3/C-47 series with Pratts had a nice sweeping carb inlet travelling through about 100 degrees but later ones had the top corner a sharp angle and they were more efficient. Never did see an explanation for that but I would hazard a guess it is related to Bernoulli's law and converting velocity into pressure.
Some Blenheim fighters were equipped with a 20mm fitted in the nose.An improved Whirlwind, and Spitfire Mk. III's. Now THERE is a What If scenario for 1940!
Slapping some Merlin I's with big chin radiators on a Blenheim will make it go a little faster, but it is still dragging a bomber fuselage and wings through the air. It would still struggle to intercept the German Schnellbombers, or Ki-27 and G3M's in the far east. A lot of effort to bring a 15000 lb airplane into firing range, eventually, with just 4x .303 machine guns.
Maybe the bomb aimers position could be faired off, and replaced with a battery of Hispano's?
Basically it seems like the inlet duct has to go through the triangle shape in rib just over the tube that is part of the engine mount or it somehow has to come through the circular hole in the main spar after going through the rib.
There a lot of detail about the exhausts in the model thread. It looks like the outlet is about where 2nd and 3rd (at best) exhaust ports are in the cylinder head. Unless there are interior partitions in that thing there are a lot conflicts in direction and flow. Cooling the exhaust gases may help with not setting fires and may help with less visible exhaust for night flying but it sure doesn't help with exhaust thrust.The final layout of exhausts is also kinda meh, with a good deal of exhaust stream going forward and then going back.
A recent exchange of letters published in "Aeroplane" magazine also referred to a whirlwind that was returned to Rolls Royce in an attempt to improve the power of the peregrine engines. Rolls Royce found that the air intakes to the engines were too small and followed a convoluted path , they modified the aircraft sent to them and gained a considerable increase in power. Apparently the modifications were dismissed by Westland because Rolls Royce were just car engine people and knew nothing about aeroplane construction. I think that it's great that you are building a Whirlwind and look forward to seeing it at Hawkinge.
This may be a result of tying to build flame suppression exhaust systems for night flying.As for the exhausts - they were no worse than what many Hawker and other aircraft had - it was an in thing for some reason for a while in Britain.
Some views of the RR intakeThe later C-47s (and a number of other radial engines) had sand filters installed at the rear of the inlet, the actual air inlet curved down a little earlier. The solid particles tended to go straighter and go through the curved slats at the sharp bend to the outside of the actual intake tract. There were different designs, sometimes the dirt trap was in front(?) like Martin Baltimores? Some P-38s had two inlets. The normal one on the outside of the cowl and an inner one with a filter that drew from the landing gear well. Obviously only used for take-off and landing but that is when dust/dirt was the worst.
Like a lot of other things they were learning a lot between 1936 and 1942-43 in regards to airflow and later installations that look similar from the outside may be a lot better than early installations. Larger passages and gentler bends can do a lot.
For the Whirlwind I can't find any photos of the air intake (inside the radiator bay?) or how the air gets to the top of the engine nacelle behind the oil tank.
Location of the oil tank made sure that such an air intake will stick out like a sore thumb, increasing the drag inordinately.The issue: While the RR intake allows the Peregrine to make full power, the drag of the intake makes the Whirlwind slow despite the extra power.
Hence the statement that RR should stick to designing cars.
I am just an old firefighter but with water putting kinks and turns in hoses/pipes can lead to a lot of pressure/flow losses.
I imagine that air is the same. The Allison P-40 and P-51s had a really nice intake, Long and smooth with one roughly 90 degree turn into the carb.
109 used one 90 degree bend, Early Spitfire used one 90 degree bend