DIY Wind Tunnel! (build & experiments)

This is a wind tunnel (or smoke tunnel) that I built in the garage. So far I've used it to visualize lift, wake turbulence, and tip vortices. with the addition of a digital scale and windspeed meter It could be used to measure lift and drag and estimate a wing's efficiency etc. Materials used include: dollar store foam-board, straws, packing tape, cardboard shipping tube, low speed blower fan, dimmer switch for fan speed control, vaporizer filled with mineral oil & connected to shop compressor at LOW pressure, copper tubing from the hobby shop for the smoke output tree LED lights and black paper to make the model and 'smoke' easier to see straws are used as 'flow straighteners' which cancel out any turbulence in the air so it enters the test section as 'laminar' flow, all the air molecules moving in the same direction at the same speed. air is drawn through the test section by a fan on the exhaust side, rather than blowing the air in through from the front. This way pressure is more evenly distributed in the incoming air.