Patent ID: 7040158

Claim:
A method for determining inner and outer boundary layer length scales of a cylindrical body, said method comprising the steps of: providing a vehicle including a tow strut extendable into a fluid medium, a load cell mounted on the tow strut for measuring strain and outputting an analog voltage signal, and a computer interface for digitizing the analog voltage signal and for transmitting the signal to a host computer; attaching the cylindrical body by a tether to the load cell of the vehicle for towing the cylindrical body through the fluid medium; towing the cylindrical body with the vehicle at a predetermined speed; measuring a total drag on the cylindrical body with the load cell; truncating the cylindrical body at a non-attached end by a fixed segment; repeating said towing, measuring and truncating steps over a majority of a length of the cylindrical body; determining a difference in total drag between consecutive measurements to derive a spatially and temporally averaged mean wall shear existing on each segment of the cylindrical body; and calculating inner and outer boundary layer length scales from said mean wall shear derivation.