A detonation driven injectant heater for pulse facility testing applications

Mixing and combustion research with the injection of room temperature (cold) light gases into a hypervelocity stream is routinely conducted in the NASA-"PULSE expansion tube facility located at GASL To obtain hated injectant data, which is desirable in certain cases to more closely replicate a flight situation, a reflected shock tunnel has been designed and built to deliver light gases at total temperatures of 800-1500 K and the necessary mass flow rates. Operation of the injectant heater is accurately synchronized with the operation of "PULSE to achieve simultaneous arrival of test flow and injectant in the model by using a -J detonation-wave driver. The detonation is initiated at the primaty diaphragm station and travels upstream into a detonable mixture of hydrogen and o v e n , while simultaneously driving a shock wave into the injectant held in the shock tube. Initiation of this process is via a double diaphragm sectioq which is itself filled p density y ratio of specific heats Subscriptskuperscnpts: u ambient CI Chapman-Jougnet conditions d properties immediately following detonation p plenum after pressure and velocity equilibration in reflected shock region. RS property immediately behind reflected shock s shock 1 injectant fill condition in driven tube 4 poStdetonation condition alter expansion to zero velocity 100 detonable mixture fill condition in driver tube * sonic with a combustible mixtnre and spark ignited. lntrnductinn The operation of a detonation-wave driven shock t u ~ e l i s described along with the mxnetn, and design of the HYPULSE iniectant To qnantlfy the effects of injecting light gases such as hydrogen and helium at elevated heater. Predictions for optimized perfoAance when driving light gases are presented as well as calibration data for the device. Included are measurements of driver gas arrival time. temperatures into hypersonic flow streams, GASL has designed and tested a detonation driven shock tunnel that provides heated light gas at temperatures of 800-1500 K and mass flow rates of up 0.03 kg/s. It is synchronized to Nomenclature u soundspeed M Machnumber p pressure R gas constant T temverature the operation of the HYPULSE expansion tube,' which is a real-gas aerothermodynamics and combustion simulation facility capable of velocity and Reynolds number duplication at conditions to flight Mach 25. Investigation of the flow structure and mixing of injectant flows in hypewelocity streams is necessary for continued development of advanced, high performance aerospace u vclocity .Senior Scicntist; Member A I M .. Senior Scientist; Member NAn Principal Scientist; Mernhcr A I M ... Copyright