CFD Evaluation of Mach 17 HYPULSE Scramjet Combustor Data

Three-dimensional finite rate chemistry solutions are performed on a single fuel injector configuration. The results are compared with limited experimental data obtained from the HYPULSE expansion tube facility at simulated flight Mach 17 flow conditions. All comparisons, except for wall heat flux, were in excellent agreement. Key findings from this study are useful in interpretation of the experimental measurements

Flow Enthalpy Effects On Scramjet Mixing And Combustion

The three-dimensional nature of the mixing process in a scramjet combustor is analyzed by examining the stream- wise vorticity-driven macro-mixing as well as the shear- driven small scale mixing. First, results of the numerical simulation of 15 degree downstream helium injection into a unconfined Mach 6 airstream are discussed. Details of downstream mixing and mean flow are in good agreement with experimental data. Results of the numerical simulation of similar hydrogen injection into a high enthalpy (Mach 17) confined Mach 6 airstream are then presented. The low enthalpy inflow from the unconfined case was then provided to the high enthalpy geometry in order to study the feasibility of using low enthalpy simulations of mixing for scramjet flight performance estimation. Results indicate that the mixing is substantially lower for the high enthalpy case. Production and decay of axial vorticity, cross-flow velocities, and the mean-flow velocities of these confined flows are related and discussed to illustrate the effect of residence time on jet mixing. The concept of lifting length (the effective distance an average fluid particle travels in the cross-flow direction over the combustor length) is introduced in order to explain the important contribution of axial vorticity to mixing in both high and low enthalpy flows. Scaling laws and suggestions for scaling improvements for actual three dimensional vortical scramjet combustors are discussed

Towards synthetic biological approaches to resource utilization on space missions

This paper demonstrates the significant utility of deploying non-traditional biological techniques to harness available volatiles and waste resources on manned missions to explore the Moon and Mars. Compared with anticipated non-biological approaches, it is determined that for 916 day Martian missions: 205 days of high-quality methane and oxygen Mars bioproduction with Methanobacterium thermoautotrophicum can reduce the mass of a Martian fuel-manufacture plant by 56%; 496 days of biomass generation with Arthrospira platensis and Arthrospira maxima on Mars can decrease the shipped wet-food mixed-menu mass for a Mars stay and a one-way voyage by 38%; 202 days of Mars polyhydroxybutyrate synthesis with Cupriavidus necator can lower the shipped mass to three-dimensional print a 120 m(3) six-person habitat by 85% and a few days of acetaminophen production with engineered Synechocystis sp. PCC 6803 can completely replenish expired or irradiated stocks of the pharmaceutical, thereby providing independence from unmanned resupply spacecraft that take up to 210 days to arrive. Analogous outcomes are included for lunar missions. Because of the benign assumptions involved, the results provide a glimpse of the intriguing potential of ‘space synthetic biology’, and help focus related efforts for immediate, near-term impact