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This work presents an unsteady Reynolds-Averaged Navier-Stokes simulation study of a model scramjet combustion chamber with a staged injection configuration containing a lobed strut injector. The simulations are based on a novel fluid dynamics solver for supersonic combustion embedded within the open-source software package OpenFOAM. Two combustion modes are investigated and compared. Furthermore, the computational method is utilized to simulate the combustor ignition sequence initiated by the shock train exiting the combustor towards the ambient laboratory atmosphere. Computational results are validated with experimental wall pressure data and high speed photography.

A newly developed numerical solver for supersonic flow is validated using a non-reacting, hot gas channel flow. The solver is embedded into the open-source software package Open-FOAM, thus allowing massive code parallelization. It uses a transient approach and includes the support of multi-species transport and chemical reactions. A local time stepping technique is applied to remedy the effects of the acoustic Courant number restriction and to speed up convergence. The evaluation is conducted using both experimental data and numerical results of a commercial CFD code. Different flow Mach numbers and wall resolution techniques are evaluated and compared. Two-and three-dimensional simulations with the new solver are shown to provide quasi-steady-state solutions which are comparable to those of the commercial code. In addition to the investigation of the hot gas channel flow Schlieren images obtained for cold flow conditions are compared to the numerically predicted flow field and good agreement is demonstrated. The presented work provides a supersonic channel flow test case, which establishes the basis for further enhancement of our newly created solver.

Large spacecraft represent a large investment of time and money, and are often risky ventures. The ability to visually inspect craft provides operators and engineers valuable information about on-orbit failures or salvagability. To minimize the risk of damage to the large craft, initial inspection maneuvers should be designed to maintain a safe observation distance. This paper discusses the design of such an inspection maneuver using range measurements that are directly applicable to stereo vision and are supplemented with gyroscope data to determine distance and rates in a relative frame. Using the SPHERES satellite testbed, the ultrasonic measurement system is used in place of vision hardware to test the vision-navigation algorithm in a microgravity environment. The paper discusses the error characteristics of the system and develops the control framework for the inspection maneuver. The implementation of the algorithm in simulation is compared with test results from the SPHERES satellites onboard the International Space Station.