Numerical Simulations of Commercial Aircraft Wakes Subjected to Airport Surface Weather Conditions

Abstract

Using tower e yby data for validation, we have developed a two-dimensional numerical simulation of the ine uence of surface weather conditions on wake vortex motion and decay for representative commercial aircraft. Our simulations support the conjecture that the ratio of eddy viscosity to kinematic viscosity, appropriate for modeling aircraft wakes, scales linearly with circulation, which yields a nominally constant equivalent Reynolds number for all commercial aircraft sizes. We have tested the constant eddy viscosity approximation for three different aircraft types and six surface weather states, showing the utility of the approach in predicting wake vortex motion and decay. Subsequently, we have shown how data from one aircraft e ight test can be used to infer the decay behavior of another, and we have examined the ine uence of the six surface weather states on the vortex decay behavior predicted for a large commercial aircraft. Based upon these simulations, we have determined that the two-dimensional, constant eddy viscosity approach can be useful in assessing the ine uence of surface weather conditions on wake vortex decay.