A Hydrodynamic Theory for Cavitating delta Wing Hydrofoils

摘要

The status of hydrodynamic theories is reviewed, and it is found that asymptotic results for limiting conditions of cavitation (i.e. large and small cavitation numbers) in earlier work by Tulin are incorrect. The mathematical problem of conical flow for cavitated delta wings of fairly wide apex angles is recast with a new 'closure' condition replacing the previous condition of no source-like flow in a transverse plane. The results obtained for lift coefficient, for apex angles up to 60 degrees, as a function of angle of attack and cavitation number are compared with available experimental data. The comparison indicates good agreement of the new theory for delta wings with apex angles up to 45 degrees. Thus, differences in results obtained using different mathematical and physical models are delineated, together with information on the respective regions of validity by virtue of comparison with experimental data. (Author)