Laminar Boundary Layer Stability on a Heated, Underwater Body

A large (3.05m long x 0.32m diameter) heated-surface, axisymmetric body, designed for transition research in a 1.22m diameter water tunnel is described. Boundary layer transition data are presented as functions of the heating power supplied to the body and the total concentration of free-stream particulate matter in the water. Body surface temperatures range from 0 to 25 deg C over the ambient water temperature, and the total heat supplied ranges from 0 to 93.3 kW. Transition arc length Reynolds numbers are found to vary from 4.5 million for the body operating cold to 36.4 million for the maximum heat level considered. The concentration of free-stream particles is shown to affect transition Reynolds number. These particles range in diameter from 10 to 70 micron and their concentration ranges from less than 5 to 198 particles per cm3. The decrease in transition Reynolds number due to the higher concentration of particles is of order 30 percent. Laminar, Boundary layer, Heated, Underwater, Body.