Re: Aerodynamic Theory

From: Thayer Syme <thayer_at_gryffinaero.com>
Date: Sat, 29 Mar 2014 23:00:22 -0400

Thanks for the clarification Ron.

Thayer


>". . . giving the spiral propwash effect more credit than it deserves . . ."
>
>
>There's been extensive research as per Tom Hunt and Northrop Grumman
>in recent years that the dominant force in a propeller's affect on
>the airframe is the "P" factor. The tendency to turn at an
>increasedgf or increasing angle of attack is a result of the
>relative difference in pitch between the propeller's two blades at
>increasing airframe angles of attack.
>
>There's also evidence (which I'm not inclined to substantiate - to
>lazy to do the req'd research) that the affect of propwash is gone
>within a distance less than the propeller's diameter behind the
>prop. In other words it dissipates before it reaches a flying or
>control surface. If I remember correctly, even the many, many bladed
>props one sees on such as a C130 have little effect just a short
>distance behind the prop's disc.
>
>
>On Sat, Mar 29, 2014 at 8:18 PM, Thayer Syme
><<mailto:thayer_at_gryffinaero.com>thayer_at_gryffinaero.com> wrote:
>
>
>
>Yes to which question?
>
>>Yes.
>>
>>
>>On Fri, Mar 28, 2014 at 9:59 AM,
>><<mailto:<mailto:upwind120_at_gmail.com>upwind120_at_gmail.com><mailto:upwind120_at_gmail.com>upwind120_at_gmail.com>
>>wrote:
>>
>>
>>Wouldn't a sub-rudder make a model turn right? Or am I giving the
>>spiral propwash effect more credit than it deserves?
>>a.
>
>
>
>
>
Received on Sat Mar 29 2014 - 20:00:26 CET