Accession Number : AD0906399

Title :   Effects of Variations in Triple-Ejection-Rack-Fairing Geometry on Separation Characteristics of Two Stores from the F-4C Aircraft.

Descriptive Note : Final rept.,

Corporate Author : ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFS TN

Personal Author(s) : Summers, Willard E.

Report Date : DEC 1972

Pagination or Media Count : 104

Abstract : Separation trajectory data were obtained to assess the effectiveness of triple ejection rack (TER) geometry changes in reducing the nose-down pitch motion of the SUU-51 B/B and M-117 stores during separation from the rack on the inboard wing pylon of the F-4C aircraft. Eleven different TER configurations, consisting of changes in the forward and/or aft fairing geometry, were used during the test. Effects on the trajectories resulting from changes in the SUU-51 B/B fin geometry and the addition of a stagnation plate covering one fin quadrant of the SUU-51 B/B were also obtained. In addition, pressure distribution data were obtained on an ogive-cylinder store in the carriage position on the standard TER and on a TER with a modified forward fairing. Separation trajectory data were obtained at Mach numbers of 0.66 and 0.90, and pressure data were obtained at a Mach number of 0.90. The trajectory data show that only one modification to the TER forward fairing reduced the store nose-down pitch (relative to the standard TER) at both Mach numbers. Addition of the stagnation plate covering one fin quadrant of the SUU-51 B/B reduced the nose-down pitch at M Free-Stream Mach Number = 0.90 and produced a nose-up pitch motion at M Free-Stream Mach Number = 0.66. Pressure data on the ogive-cylinder store (on TER position No. 1) show that about 75 percent of the nose-down pitching moment results from the pressure distribution on the store surface forward of the center of gravity and that the reductions in pitching moment resulting from modification to the forward fairing of the TER also are caused by pressure changes on the forward portion of the store. (Author)

Descriptors :   (*BOMB RACKS, JET FIGHTERS), (*BOMBS, EJECTION), RELEASE MECHANISMS, SEPARATION, FAIRINGS, EXTERNAL STORES, PITCH(MOTION), REDUCTION, AERODYNAMIC CONFIGURATIONS, WIND TUNNEL MODELS, DESCENT TRAJECTORIES, FINS, PRESSURE, OGIVES, CENTER OF GRAVITY, SWEPTBACK WINGS, WING BODY CONFIGURATIONS, AERODYNAMIC CHARACTERISTICS, AVIATION SAFETY, TRANSONIC FLOW.

Subject Categories : Aerodynamics
      Attack and Fighter Aircraft
      Aerial Bombs

Distribution Statement : APPROVED FOR PUBLIC RELEASE