COMPUTER SIMULATION OF TRANSIENT OPERATION OF SMALL BIPROPELLANT ENGINES

A COMPUTER CODE (SIMULTRAN) IS TO BE DEVELOPED THAT, BY SIMULATING THE TRANSIENT OPERATION OF THE PROPULSION SYSTEM,WILL CALCULATE THE CONTAMINANT PROPERTIES AT THE NOZZLE EXIT-LANE. THE INTENDED USER FOR THE SIMULATOR IS THE ENGINEER WITH A BACKGROUND IN PROPULSION. USEE INTERFACE AND OUTPUT MANAGEMENT IS PROVIDED BY AN EXPERT SYSTEM. EXISTING TRANSIENT CODES WILL BE MODIFIED, IMPROVED AND INTEGRATED; A UNIQUE FEATURE OF THE PROGRAM IS THAT THE CHAMBER PHENOMENA ARE SIMULATED FROM RAREFIED REGIME TO STEADY-STATE CONDITIONS. PRESENT TECHNIQUES TO PREDICT CONTAMINATION FROM SMALL BIPROPELLANT ENGINES ARE DEFICIENT,REQUIRE ADVANCED EXPERTISE, AND LACK EXPERIMENTAL VERIFICATION. THE SIMULATOR CAN ALSO BE EMPLOYED TO DEVELOP STABILITY RATING CRITERIA AND TRANSIENT PERFORMANCE SPECIFICATIONS. PHASE I WILL ESTABLISH THE OPERATIONAL ASPECTS OF THE SIMULATOR AND THE FEASIBILITY OF THE APPROACH WILL BE DEMONSTRATED WITH TWO SAMPLE CASES. IN PHASE II, THE CODE WILL BE UPGRADED TO SIMULATE 3-DIMENSIONAL TWO-PHASE FLOW, AND EXPERIMENTAL WORK WILL BE CONDUCTED TO VERIFY INJECTOR FLOW DYNAMICS. THE TRANSIENT BURNING OF PROPELLANT DROPLETS WILL BE VERIFIED IN A SMALL VERTICAL SHOCK TUBE FACILITY. IN PHASE III, ERGO-TECH WILL USE THE CAPABILITIES FROM THIS EFFORT TO DEVELOP THE SPECIFICATIONS FOR A TEST STANDARDIZATION TO CHARACTERIZE SMALL BIPROPELLANT ENGINES.