Long Island Junior Soccer League

An investigation into whether or not MicroElectroMechanical Systems (MEMS) would be a viable alternative to provide directional control of high-speed projectiles has been conducted. Where as conventional control systems make use of actuators to rotate canards or fins, these systems require larger, higher drag fins to counteract their aerodynamic effect, which could result in a significant loss in range, accuracy, and performance. Computational Fluid Dynamic analyses were conducted to verify that small perturbations in the flow can create macro-level forces capable of providing directional control to these projectiles. Presented herein are the results of these simulations as well as wind tunnel data validating the computational experiments. Additionally, a factorial experiment taking into account four different geometric variables defining the ramp was conducted in order to determine the key parameters affecting lift. The tests indicated that the ramp height and the distance of said ramp from the canard leading edge are the more influential parameters. With these results, an optimized configuration was developed which increased the lift coefficient by at least 36 percent.

Scramjet engines have long been considered potential propulsion systems for low­cost access to low­Earth orbit, as well as long­range intercontinental flights. For this concept to be viable, however, additional work is necessary in designing engines that can be operated using commercially­available hydrocarbon fuels. Due to the complexities of such fuels, an increased understanding of the pyrolytic nature of these fuels in the presence of various catalysts would be invaluable in the design of fuel­cooled structures for scramjet engines. In addition, it is advantageous to manipulate the specifics of the fuel reformation process, in order to generate a product stream which will ignite and burn as quickly as possible. In support of these ends, a set of experiments was conducted, investigating the use of short contact­time reactors in the endothermic reformation of important logistical fuels, such as JP­8 and others. The primary aim of this research is to prove that short­contact­time catalysts represent a feasible way to catalytically reform jet fuels into gaseous products, particularly ethene. Using a novel, short­contact­time approach, feasibility tests were done to determine the extent of conversion and selectivity to ethene and hydrogen. Preliminary results show that as space velocity increases, the conversion and selectivity actually increase. Based on the results of these studies, some chemical kinetic simulations were performed, in order to evaluate the impact of the fuel reformation on the ignition characteristics of the fuel. The results of these simulations can be used to optimize fuel reforming for engine performance.

In this paper, thermal buckling of doubly clamped microfabricated nickel beams is implemented as a passive actuation mechanism to drive temperature-regulated nonlinear micro-valves for adaptive microcooling applications. The nonlinear buckling phenomenon is combined with the nonlinear change in flow rate through parallel plates with a variable spacing. The thermal buckling mechanism and parallel plate flow are modeled analytically, and nondimensional characteristic design curves have been generated. Passive flow-control microvalves were fabricated using deep reactive ion etching and a through-mold nickel electroplating process over a thin sacrificial layer. The model is validated with experimental results from the microfabricated temperature-regulated microvalves. Experimental characterization using an integrated micromachined heat exchanger with air as the working fluid shows the desired nonlinear valving behavior with mass flow rates of up to 5 mg/s for a temperature increase of 50degC, corresponding to 0.25 W of heat removal. It is shown that temperature-induced elastic instabilities in microfabricated structures can be modeled and manipulated to create a nonlinear adaptive valving mechanism. The modeling approach, microfabrication process, and full characterization of the microvalves are presented.

not Available.

A series of Hyper-X Mach 10 flowpath ground tests are underway to obtain engine performance and operation data and to confirm and refine the flowpath design methods. The model used is a full-scale height, partial-width replica of the Hyper-X Research Vehicle propulsive flowpath with truncated forebody and aftbody. This is the fifth test entry for this model in the NASA-HYPULSE facility at GASL. For this entry the facility nozzle and model forebody were modified to better simulate the engine inflow conditions at the target flight conditions. The forebody was modified to be a wide flat plate with no flow fences, the facility nozzle Mach number was increased, and the model was positioned to be tested in a semi-direct-connect arrangement. This paper presents a review of the test conditions, model calibrations, and a description of steady flow confirmation. The test series included runs using hydrogen fuel, and a silane-in-hydrogen fuel mixture. Other test parameters included the model mounting angle (relative to the tunnel flow), and the test gas oxygen fraction to account for the presence of [NO] in the test gas at the M10 conditions.