ORIGINAL: davidej
Been reading this thread and saw the often-stated claim that a motor at tickover provides more drag than when deadstick.
I find this counter intuitive. It would need a change of aerodynamic regime over the prop at some point to be true.
had anyone got any real evidence to support it or a sound theoretical arguement why it should be so. I find these "you will notice when ...." statements totally lacking in any real proof.
Incidentally yachtties continually argue as to whether you shoud sail with the propeller windmilling or whether you should apply the shaft brake, so they have the same problem.
Any help would be appreciated.
David
It is a well known fact :-) amongst aeronautical engineers that under certain conditions a windmilling propeller will produce more drag than a stationary propeller. As usual things are more complicated than they appear at first glance.
I am quite certain I have some scientific articles in my archive with hard facts, but for the time I suggest you look into this thesis where there are some measurements and analysis of the drag of windmilling propellers.
[link=http://www.goshen.edu/physics/PropellerDrag/thesis.htm]Propeller Drag Thesis[/link]