IV
Table of Contents
1 IXV: The Mission and the Vehicle ... 1
1.1 Mission Overview ... 2
1.1.1 Mission Profile ... 2
1.1.2 Mission Objectives ... 8
1.2 Intermediate Experimental Vehicle ... 9
2 Reaction Control System ... 12
2.1 RCS Function ... 12
2.2 RCS Architecture ... 13
2.3 Major RCS Components ... 20
2.3.1 Thrusters ... 20
2.3.2 Propellant Tank ... 22
2.3.3 Fill/Drain Valve and Test Port ... 23
2.3.4 Pyro Valves ... 24
2.3.5 Latch Valve ... 26
2.3.6 Filter ... 27
2.3.7 Equipped Tubing Sets ... 27
2.3.8 Calibrated Orifice in the By-Pass Line ... 28
2.3.9 By-Pass Flow Control Valve ... 28
2.4 RCS Operational Phases ... 29
2.4.1 Priming Phase ... 29
2.4.1.1 Nominal Priming Operation ... 29
2.4.1.2 Off-Nominal Priming Operation ... 30
2.4.2 Nominal Operative Phase ... 31
V
3 Hydrazine ... 33
3.1 Overview ... 33
3.2 Hydrazine and Waterhammer ... 35
3.3 Hydrazine Thermal Explosion ... 35
3.4 Safety Requirements ... 36 3.4.1 IXV-RCS Architecture ... 36 3.4.2 Temperature Limits ... 36 4 EcosimPro ... 39 4.1 Overview ... 39 4.2 ESPSS Libraries ... 41
5 Design and Simulation of Bunker & Baker Priming Test Case ... 43
5.1 Introduction ... 43
5.2 Reference Case ... 44
5.3 Sensitivity Analysis ... 60
5.3.1 Initial Pressure of the Liquid in Pipe_Liquid ... 61
5.3.2 Initial Pressure of the Gas in Pipe_NCgas ... 62
5.3.3 Initial Temperature of the System ... 64
5.3.4 Diameter of the Pipes ... 64
5.3.5 Length of the Pipes ... 66
5.3.6 Mechanical Properties of Pipe Material ... 70
5.3.7 Valve Behaviour ... 70
5.3.8 Working Fluid ... 74
5.3.9 EcosimPro Damping Factor ... 75
5.3.10 Acceleration ... 77
5.3.11 Variable Diameters in Pipe_NCgas ... 79
5.3.12 Driving Pressure ... 81
5.3.13 Pipe Rugosity ... 81
5.3.14 Heat & Momentum Transfer between Working Fluid and Wall ... 82
5.4 Fundamental Results ... 83
VI
6 IXV RCS Components: Behaviour ... 86
6.1 Introduction ... 86
6.2 Maximum error and margin of tolerance ... 87
6.3 Working Fluids ... 88 6.4 Mock-Up ... 89 6.4.1 Latch Valve ... 89 6.4.2 Filter ... 91 6.4.3 Adapters ... 93 6.4.4 Pyro Valves ... 96 6.4.5 Propellant tank ... 98 6.4.6 Tees ... 99 6.4.7 Summary ... 99 6.4.8 By-Pass Line ... 100
6.4.8.1 Solenoid Valve of the By-Pass Line ... 100 6.4.8.2 Orifice ………..……… 105
6.4.8.2 Orifice ... 101 6.5 Flight-Hardware ... 102 6.5.1 Latch Valve ... 102 6.5.2 Filter... ... 103 6.5.3 Adapters ... 104 6.5.4 Pyro Valves ... 108 6.5.5 Propellant tank ... 110 6.5.6 Tees... ... 111 6.5.7 Summary ... 112 6.5.8 By-Pass Line ... 112
6.5.8.1 Solenoid Valve of the By-Pass Line ... 113 6.5.8.2 Orifice ………..……… 117
6.5.8.2 Orifice ... 114 6.5.8.2 Orifice ………..……… 117
7 IXV RCS Components: EcosimPro Correlation ... 115
7.1 Introduction ... 115
7.2 Mock-Up ... 116
VII 7.2.2 Filter ... 121 7.2.3 Adapters ... 123 7.2.4 Pyro Valves ... 134 7.2.5 Tank Outlet ... 139 7.2.6 Tees ... 141
7.2.7 Solenoid Valve of the By-Pass Line ... 142
7.2.8 Orifice ... 144 7.3 Flight-Hardware ... 146 7.3.1 Latch Valve ... 146 7.3.2 Filter ... 148 7.3.3 Adapters ... 150 7.3.4 Pyro Valves ... 158 7.3.5 Tank Outlet ... 161 7.3.6 Tees ... 162
7.3.7 Solenoid Valve of the By-Pass Line ... 163
7.3.8 Orifice ... 164
7.4 Conclusions ... 166
8 IXV RCS: Pressure Drop ... 167
8.1 Introduction ... 167 8.2 EcosimPro Model ... 168 8.2.1 Tees ... 170 8.2.2 Lines ... 176 8.3 Pressure Drop ... 177 8.3.1 Mock-Up ... 179 8.3.2 Flight-Hardware ... 185 8.4 By-Pass Line ... 191 8.4.1 Flight-Hardware ... 193 8.4.2 Mock-Up ... 194 9 IXV RCS: Priming ... 195 9.1 Introduction ... 195
VIII 9.2 Acceptance Criterium ... 196 9.3 Nominal Priming ... 198 9.3.1 Mock-Up ... 198 9.3.2 Flight-Hardware ... 205 9.3.3 Conclusions ... 214 9.4 Off-Nominal Priming ... 214 9.4.1 Mock-Up ... 215 9.4.2 Flight-Hardware ... 223 9.4.3 Conclusions ... 230 10 Conclusions ... 231 Appendix A ... 235 Appendix B ... 237 Appendix C ... 248 Appendix D ... 253 Appendix E ... 257 Bibliography ... 258
