High Performance Computational Modeling of Unsteady Surface Loads in Complex Weapons Bays

Abstract

This paper presents high performance computing results from applications of the CRAFT CFD ® software to complex weapons bay configurations. Several flow control concepts have been developed based on past experience with smaller length-to-depth ratio (L/D) cavities with the intended application being a more complex and longer weapons bay. The goal in this paper is to document work done to build confidence in the modeling capability to evaluate flow control concepts for complex weapons bay configurations. The effects of some fundamental bay geometric changes are examined through Large Eddy Simulations. These simulations are validated against measurements and then used to understand the mechanisms involved.The results demonstrate that the extension of previous generic cavity modeling on shorter bays to the longer geometrically complex bay is not straightforward.

A Computational Study of Flow Within Cavities with Complex Geometric Features

“…Study of this canonical family of cavity flows has led to improved fundamental understanding of the origins and mechanisms of pressure fluctuations within the cavity. However, a real weapons bay geometry is often much more complex than the simple rectangular cavity, and there is evidence that geometric features such as bay doors, a ramped floor, jagged cavity lip, and others, can cause significant and important changes to the flow-field and resultant aero-acoustic environment within the bay 6 .…”