1. AAE450 Spring 2009 Lunar Lander Main Engine 1.Overall system design 2.Performance Optimization 3.Jointly worked on thrust and CEA based script to allow quick and accurate engine sizing for larger payloads Thaddaeus Halsmer Thursday, February 26, 2009 Thaddaeus Halsmer, Propulsion

2. AAE450 Spring 2009 Thaddaeus Halsmer, Propulsion 1 System layout and fluid control components 1.High Pressure Helium tank – 24.13 MPa (3500 psi) Pressure for oxidizer feed system Purge system 2.Oxidizer tank – 3.103 MPa (450 psi) H 2 O 2 storage 3.Fluid lines and control devices Fig. 1: Fluid system diagram SV01 SV02 High Pressure Helium Tank HV01 REG CK01 CK02 MOV F01 H 2 O 2 Tank HV02 * Not to scale RV01

3. AAE450 Spring 2009 Thaddaeus Halsmer, Propulsion 2 Performance analysis refinement  Increase Isp from 295 to 320’s 1.Choose 98% H 2 O 2 Isp increases with concentration 2.Optimize nozzle mass/area ratio Area ratio = 100 3.Estimate average Isp O/F changes with time Isp ave = -0.036*tb + 337

4. AAE450 Spring 2009 Thaddaeus Halsmer, Propulsion 3 Nozzle area ratio and mass optimization: As area ratio, ε, increases M nozzle increases, but Isp increases also As Isp increases M prop decreases for a given thrust and burn time Wrote Matlab script that used Matlab CEA interface to compute multiple Isp’s for different area ratio’s and the corresponding M prop and M nozzle for a given thrust, and burn time Results: Area ratio for minimum mass occurred at ~150, however this nozzle would be very large and little is gained above ~100

5. AAE450 Spring 2009 Thaddaeus Halsmer, Propulsion 4 Backup slide (II)  O/F shift with burn time

6. AAE450 Spring 2009 Thaddaeus Halsmer, Propulsion Backup slide (III)  Reference Fluid control component price source: *Reid, Bryan, (personal communication, February 2009), Sr. Director, Aerospace Business Development, Marotta Controls Inc., Montville, New Jersey 5