Propeller Slipstream & Tailplane Instability

[kevjcarvalho]

Is the effect that the propeller slipstream (i.e the helix) hits the tailplane causing much instability quite significant such that if u are using a tractor propeller a single rudder won't work creating the need for two rudders away from the slipstream path??

 

[Cyrus]

There is no easy answer to that question, as it depends on the design of the aircraft. The effect of the slipstream is to induce a sidewash factor that modifies the verticle fins angle of attack.

 

[kevjcarvalho]

Is there any way to actually find the path of the helix?...like using CFD.

 

[Cyrus]

Sure, you can run CFD and then look at a plot of the streamlines. But that is going to be a huge under taking, and require a ton of processing power.

 

[alphy]

The effect of propeller slipstream hitting the tailplane can indeed cause instability in an aircraft. This is known as propeller wash or propeller induced flow. The helical motion of the slipstream creates a swirling flow around the tailplane, which can affect its aerodynamic performance and cause the aircraft to yaw or roll.

In general, the effect of propeller slipstream on tailplane stability will depend on the design and placement of the propeller and tailplane, as well as the speed and power of the aircraft. In some cases, a single rudder may be sufficient to counteract the effects of propeller wash, while in others, additional control surfaces may be necessary.

For aircraft with a tractor propeller, the placement of the rudder in the slipstream path may not be enough to counteract the effects of propeller wash. In this case, using two rudders placed away from the slipstream path can help to provide better control and stability.

Ultimately, the design of an aircraft and its control surfaces must take into consideration the potential effects of propeller slipstream on tailplane stability. Careful consideration and testing are necessary to ensure safe and stable flight.