# Tag Info

5

On a twin with a single fin and rudder, the only significant propeller wash factor is propeller P Factor, as it offsets the thrust line to the right of the propeller axis (for a clockwise-from-behind propeller). So the right engine's net thrust line is farther away from the airplane's longitudinal axis than the left's, and more rudder is required to counter ...

4

Can prop wash from a live engine contribute a sideways force on the aircraft? Absolutely. For a twin-engine aircraft with wing-mounted engines with propellers: If the failed engine is the "critical engine", then any sideforce and yaw torque from the spiralling slipstream will increase the yaw torque and sideforce that the rudder must generate to ...

4

Forces away from the center of gravity tend to produce rotation from their torque. While technically true, I feel that this sentence can be a little misleading. If you push on the side of a body (such as an airplane), assuming there are no other forces acting on it, the body will both rotate around its center of mass, and move sideways. In other words, ...

3

As an addendum to Anonymous Physicist's answer: Car type catalytic converters consist of mesh or honeycomb structures seeking to get the majority of the molecules in the stream exposed to the catalyst. By definition this prevents optimal supersonic flow since there must be interaction between fixed parts of the cat structure and the entire flow volume, ...

2

The absolute MTOW is a limit imposed by structural considerations, not altitude limitations. At every point on earth, a max allowable TO weight must be established by the pilots based on runway length, pressure altitude, climb performance etc. The service ceiling can be reached at structural MTOW: it is defined as the altitude where the maximum rate of climb ...

2

Ignoring drag losses, the force generated by a jet engine is (mdot fuel + mdot oxidant)*exhaust velocity. (mdot is mass flow rate: mass per time) If the catalyst retards the velocity of the exhaust jet, then you are just killing the force generated by the jet engine. And when I think of a catalytic converter, I think of long, narrow channels and lots of ...

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This is a quite old post but I found the same equation on weather.gov a few days ago and I asked myself the same question: where does that formula come from? It looks like it can indeed be derived from equation (33a). For simplicity, I rewrote it with $H_b=0$ and $\frac{R}{M}=R_s$ as: $$P = P_0\left(\frac{T_0}{T_0+LH}\right)^{\frac{g}{R_sL}}\tag{1}$$ The ...

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A fluid catalyst would not make any sense. It would get ejected from the engine, defeating the point. A solid catalyst could improve efficiency, but the improvement would be minuscule. Solid catalysts work at the surface. Compared to the mass flow through a jet engine, the surface available to be coated with catalyst inside the engine is extremely small. ...

1

A large Bergen diesel will use 175 g/kWh at 85% of max load. At 600 kW per cylinder so a v16 is 10 MW or 13,000 shp. It will also weigh 150 tonnes, vs a TP400 gas turbine that weighs 2 tonnes and generates 11,000 shp at 210 g/kWh https://www.rolls-royce.com/~/media/Files/R/Rolls-Royce/documents/marine-product-finder/diesel-and-gas-engines-brochure-1216.pdf ...

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