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What am I missing? The contribution of zero lift drag to overall drag at high speed. L/D drops to much lower values than 10 at the top speed of piston-powered airplanes. Let's take an example: Given …

Prop takeoff calculation is a bit tricky since so much changes between standstill and flight. The most important part is propeller efficiency $\eta_P$ which theoretically would become zero at rest if …

The pictures in your question show the Ju-288 V5, the first of its type to be powered by the Jumo 222 engine. Previous Versuchsmuster (V-types) used the less powerful, but larger BMW 801 (see below, s …

First of all, any radiator thrust is limited by the amount of ram pressure which can be achieved at the radiator entry. This is just 1.4 times ambient pressure at Mach 0.8, and then very little flow s …

I can think of two reasons: The efficiency of heat machines depends on the difference between lowest and highest temperature in the cycle, relative to the highest temperature, as formulated first by …

tl;dr: L/D of the airframe and specific fuel consumption of the engines are credible but that doesn't add up to the claims made regarding fuel consumption and speed relative to jets. Laminar flow seem …

When the first couple of Supermarine Spitfire fighters were deployed on a British aircraft carrier in the late 1930s, the structure was eaten away by corrosion within 6 months. The sea water spray was …

There are several benefits: piston engines are best for driving propellers. At the same shaft horse power $P$, propeller thrust $T$ varies with the inverse of air speed $v$: ($T_{Prop} = \frac{P}{v} …

It would have a gearbox between the crankshaft and the propeller. That is certain. Other very likely details would be: overhead camshafts four valves per cylinder water cooling at least for the cyl …

You need to look at the overall picture. Yes, a diesel is cheaper, but it will weigh more and be less reliable. Also, the operating time of an APU is rather a small fraction of total airframe operatin …

The BMW 801 had such a thing, essentially a mechanical/hydraulic analog computer which allowed to automatically adjust prop pitch, mixture, supercharger settings and ignition timing, all with a single …

There are three factors which limit the possible speed of piston engines: Flame speed in the fuel-air mixture, relative speed of moving parts, here the pistons in their cylinders, and Valve inertia a …

No, stacking more propellers will reduce efficiency. The case with two is an exception because the second propeller benefits from operating in the slipstream of the first. In total, both propellers ac …

You are comparing apples to oranges. Run your car engine at full throttle and measure again. The aircraft engine will look very good in comparison. Modern car engines optimise fuel consumption with …

Your reasoning is correct if engine mass is not important. Ships use huge engines, because increasing the number of cylinders beyond 8 will have diminishing returns in terms of smoothing out the torqu …