Propeller Diameter It is observed that the speed of the shaft and the propeller diameter are very closely related. A low shaft speed (given diameter) is very beneficial from efficiency point of view. However, it leads to high shaft torque subsequently large shafts and gearboxes.

2014年9月11日 · In a fan like that if I am not wrong it is moving in the right direction (clockwise). By the shape of blades I assume they create high pressure on a side closer to you but it would mean air would travel backward to a side further away from you (from high pressure to low pressure). I don't get it (or my reasoning is wrong).

2021年3月18日 · Please define your efficiency. Normally, there is an ideal case used to normalize the computation. For props, this is usually taken as open flow case. Your restrictions in 1 don't make sense. You want to fix the power input and allow the props to evolve to their best shape, which will be significantly different in each case. $\endgroup$ –

2007年7月13日 · 3) If modern fan blade shape is really efficient, is it possible that propellor-blades should also be reversed? (Many powered boats I've driven have pathetic performance in reverse, though there are often other reasons for that -- exhaust coming out the hub of the propellor, bad boat geometry for the prop "throwing" water forwards, etc.)

2017年2月23日 · Please don't forget that a regular propeller on either a piston engine or a turbine creates its motive force (moving the plane forward/upward) by virtue of its cross-sectional shape, which in fact, is that of an airfoil; yes, just like the wings. The forward surface is slightly convex, while the rear surface is slightly concave.

2009年2月10日 · May be it will be possible to make a screw propeller form with extreme strong nanotube cables. Than apply nuclear power from submarine and hold a piece of magnetic liquid on the cables. Than engine starts to turn and magnetic liquid self form for the ideal screw propeller shape with the pressure of water.? Thats what i think of , Best ,

2016年8月3日 · The required RPM (of the propeller I assume) depends on the size and shape of the blades and how much thrust you want out of it. And yes, the properties of a ship's propeller will be very different from an aircraft's. I can't say I know much about this topic, but if you can provide a bit more information I'm sure someone here can assist you.

2023年7月5日 · But pitch is the other important parameter, you can not scale performance data for that. I don't know what the typical pitch is for the propellers you are talking about. If you have the pitch you need to find a performance curve for a propeller roughly of similar shape but most importantly of similar pitch.

2008年3月9日 · A propeller leaves a helical wake, the pitch is the pitch of the blade which is greater than the pitch of the wake, but the propeller doers not go through water like a screw through wood: circulation about the blade is necessary and is generated by the vorticity shed (as wake) by the trailing edge.

2009年4月1日 · So I'm not sure if this is the right place - and its a crazy question - but I am trying to get something to spin and/or flip when I put it in a beaker of water, just by its own weight and gravity. I have tried a maple seed shape, propeller shapes, simple …