Typically, the awnings I see on Travel Trailers look different than what I see on vans. Travel Trailers tend to have awnings with exposed vertical support arms that rest against the flat side of the the Travel Trailer when in the traveling or stored position. That wouldn't work well on the curved side of a van.
Vans have awnings like what is at this link: http://www.fiammausa.com/products/awnings.asp?Fam=F01
I think they're referred to as "projection" awnings. You turn a crank to wind them out.