An effective, low-cost mechanism for direct drag force measurement on solar concentrators

An effective technique for measuring the drag force on a solar concentrator in a subsonic wind tunnel with a simply-fabricated, low-cost force sensing mechanism is described. The measurement uncertainty was reduced by ensuring operation near full scale of the load sensor employed, and by averaging a large number of samples to reduce chance variations due to turbulent fluctuations in the system. The resulting drag coefficients from our apparatus successfully duplicated previously published experimental data from a geometrically-similar, parabolic trough style solar collector.