Three-dimensional droplet impingement method for propellers of arbitrary geometry

A three-dimensional droplet impingement code for aircraft propellers has been developed. The code allows the modeling of three-dimensional propellers of arbitrary geometry, but is limited to modeling axi-symmetric spinner/nacelles combinations. The code has been used to analyze several three-dimensional wind tunnel propeller-nacelle models, which were experimentally studied. The code was also used to validate a theoretical relationship between two-dimensional and three-dimensional impingement efficiencies for rotating propellers. The effects of the spinner, engine nacelle geometry, blade to blade interaction, and the propeller advance ratio on the impingement efficiency and limits of impingement were studied.; Comparison of the 3D code results with the 3D experimental data shows reasonable agreement. When single blades without a center body or a nacelle are modeled, the 3D code results exhibit good agreement with the two-dimensional code results corrected for rotational effects. The 3D code results indicate that the nacelle and spinner geometry is the most important three-dimensional flow-field factor affecting the impingement efficiency and limits of impingement on propeller blades. The results further indicate that the utilization of the classical two-dimensional strip analysis to determine the impingement characteristics of propellers does provide a first order prediction of β _Max on 3D propeller configurations. These two-dimensional methods, however, do not adequately predict the lower and upper limits of impingement on propellers with spinners and engine nacelles.