Displaying stream lines in downwash
Does anyone have experience on displaying stream lines in the downwash of a helicopter? I will be trying to do that late this summer on a AB-412 for stream lines study around the hoist and hoist cargo (human). Will a normal smoke grenade do the trick? Downwash is too turbulent to use a conventional smoke from wind tunnel testing, i think.
I'll be very grateful for any suggestions and tips.