RD-170 JET FLOW STUDY
HISTORY
With the completion of the Enterprise, the first American space shuttle, in 1976 the Soviet Union found themselves far behind. They feared that the space shuttle would be used to deliver advanced weaponry to space. Soviet leadership determined that the USSR needed a shuttle of their own, The Buran. The Buran's Launch vehicle, Energia, would need immensely powerful engines to bring it orbit. The RD-170 would be that engine.
MESH
We generated a mesh for the converging diverging nozzle of the RD-170. The dimensions of the combustion chamber, throat, and exit were acquired from internet sources. The general shape of the nozzle was estimated from photographs. The mesh has a refinement bias that favors the wall to provide higher resolution where viscous effects will take place. I included a large field downstream of the nozzle to simulate the exhaust jet formed. The length of the rectangular field is 30x the nozzle exit radius and the height is 15x the nozzle exit radius.
SETUP
The nozzle inlet was set as a pressure inlet and the far field boundary was set as a pressure outlet. For this study tested two operating conditions for the engine: sea level and vacuum operation. I set the outlet pressure equal to 101325 Pa to simulate the sea level operation and set it equal to zero to simulate vacuum operation. The pressure inlet remained at the combustion chamber pressure of 24.7 MPa.
RESULTS
The jet flow study produced valuable results that furthered our understanding of the formation of shocks in jet flows at super and hypersonic speeds. We were able to demonstrate both over and under expanded flow in sea level and vacuum operation respectively. Simulation stability proved to be a difficult issue to overcome and we believe that the simulation has significant room for improvement to produce more usable and accurate results.
If you would like to learn about the RD-170 engine simulation project follow the links to the presentation and appendix below.