Tradeoffs among Weapon Aerodynamic Stability, Trajectory Perturbations, and F-4 Aircraft Performance.
Abstract
A series of three wind tunnel tests was conducted to determine the tradeoffs and interdependencies among weapon free stream aerodynamic characteristics, delivery aircraft performance degradation, and weapon separation trajectory perturbations. The weapon configurations tested were composed of one of three nose fairings, one of four tail assemblies, and the 800 pound general purpose warhead proposed for the Modular Weapon Series of munitions. The performance degradation was evaluated, using data from a 5% scale model of the F-4C aircraft carrying 11 weapons on inboard triple ejector racks and on a centerline multiple ejector rack, with 370 gallon fuel tanks outboard. Captive trajectories were initiated from all three positions on an inboard triple ejector rack of the F-4C model to determine the effects of nose and tail geometry on initial weapon perturbations. Limited flight test and analytically predicted trajectory data were also collected and compared to the wind tunnel results. In each wind tunnel test, data were recorded over a range of Mach numbers from 0.6 to 1.2 with Reynolds numbers on the order of 2 to 5 million per foot. Results of these tests revealed that relatively large differences in weapon free stream aerodynamic characteristics had little effect on delivery aircraft performance. The proper selection of weapon configuration did reduce perturbations in separation trajectories. However, the mutual aerodynamic interference resulting from carrrying weapons in close proximity to one another and the effects of Mach number on the strength of that interference were found to be of much greater significance than variations in the weapon geometries investigated. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1973
- Accession Number
- AD0909408
Entities
People
- John L. Holmberg