Accession Number : AD0912396

Title :   A Study of the SUU-51A/B Dispenser Munition High Speed Separation Problem and Proposed Solutions.

Descriptive Note : Final rept. Feb-Sep 72,

Corporate Author : AIR FORCE ARMAMENT LAB EGLIN AFB FL

Personal Author(s) : Holmberg, John L.

Report Date : MAY 1973

Pagination or Media Count : 54

Abstract : Several corrective modifications were proposed to alleviate the rapid nosedown pitch of SUU-51A/B dispenser munitions released from bottom triple ejector rack stations on F-4 aircraft at high subsonic speeds. These modifications were (1) adding ballast, (2) shifting the suspension points on the bottom station weapon, (3) reducing tail span and area, (4) changing the nose fairing on the weapon, (5) changing the forward fairing on the triple ejector rack, (6) adding a stagnation plate between the upper quadrant fins on the bottom station weapon, and (7) using a dual piston high impulse ejector system. An oil flow technique, carriage loads surveys, and captive trajectory simulations were employed in wind tunnel evaluations of the effectiveness of each potential solution to the pitch problem. All testing was done between Mach 0.66 and 1.1 with Reynolds numbers on the order of 2 to 4 million per foot. Each modification was tested singly and in as many combinations as were considered practical. Only two of the corrective measures (the hypothetical dual ejector system and the combination of ballast and the stagnation plate) provided sufficient relief from the pitch problem to avoid probable weapon-to-weapon contact. However, each test method and every change in trajectory resulting from one or more of the modifications provided additional insight into the nature of the interference flow field which created the separation problem. (Author)

Descriptors :   (*AIRCRAFT AMMUNITION, CONTAINERS), (*CONTAINERS, BOMBLETS), (*EXTERNAL STORES, CONTAINERS), BOMB EJECTORS, SEPARATION, JET FIGHTERS, PITCH(MOTION), SUBSONIC CHARACTERISTICS, BALLAST, AERODYNAMIC CONFIGURATIONS, FAIRINGS, FLOW FIELDS, DESCENT TRAJECTORIES, WIND TUNNEL MODELS, MODEL TESTS, EJECTION, BOMB FINS, TRANSONIC FLIGHT, COMPATIBILITY, INTERFERENCE, CENTER OF GRAVITY, BOMB RACKS, FLOW VISUALIZATION, AERODYNAMIC LOADING, LOAD DISTRIBUTION, SIMULATION.

Subject Categories : Aerodynamics
      Attack and Fighter Aircraft
      Aerial Bombs

Distribution Statement : APPROVED FOR PUBLIC RELEASE