F-111 Store Trajectory Analysis
Abstract
The analysis of store separation by computational fluid dynamics (CFD) techniques holds great promise for reducing aircraft-store certification testing. The primary concern with CFD application is the question of accuracy. This question of how much confidence should be placed on CFD generated loads data and trajectories is addressed using an uncertainty analysis technique. The process requires a formalized approach to evaluating the uncertainty associated with CFD produced loads data. This is accomplished by the use of belief function calculus to combine uncertainty estimates of fundamental metrics (grid resolution, solver complexity, accuracy of surface definitions...) into a composite uncertainty estimate for the force and moment data. This process provides the "error bars" associated with the CFD loads data. The store loads data is used in a six degree-of-freedom code to produce the nominal trajectory. The uncertainties are tracked through the process in order to provide a confidence estimate that the store will remain within a given value (e.g. 5%) of the nominal trajectory. The uncertainty analysis technique is applied to CFD force and moment data generated for the release of a Small Smart Bomb (SSB) from the forward carriage location of the F-111 aircraft at flight Mach numbers of 0.8 and 0.95.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2004
- Accession Number
- ADA468707
Entities
People
- Andrew Cary
- Rudy Johnson
Organizations
- Air Force Research Laboratory