Experimental evaluation of pressurant gas injectors during the pressurized discharge of liquid hydrogen
Year: 1966
Type: article
Abstract: An experimental investigation was conducted to determine the effect of pressurant gas injector geometry on the pressurant gas (hydrogen) required during discharge of liquid hydrogen from a 29-cubic-foot cylindrical tank. of expulsion times at a nominal operating pressure level of 160 pounds per square inch absolute and with inlet pressurant gas temperatures between 508' and 558' R. Data were obtained using six injector geometries (cone, hemisphere, disk, radial, multiple screen, and straight pipe).The first five injectors, which gave some degree of distribution or diffusion of pressurant gas into the top of the tank, were found to have similar pressurant gas requirements (within 10 percent) during the expulsion period.The straight pipe injector, which introduced the pressurant gas in a concentrated stream towards the liquid surface, showed a significant decrease in pressurant gas required for comparable propellant outflow rates.Tests were conducted for a rangeThe experimental results for the multiple screen, cone, and 1-inch-diameter straight pipe injectors were compared with results predicted by a previously developed analytical method.This comparison indicated that good agreement existed between the analysis and experimental data for the diffuser -type injectors.However, an altered analysisone which would incorporate a mixing theory to account for the radial and axial temperature gradients in the tank ullagewould be required for prediction of pressurant gas requirements when using straight pipe injectors.It was experimentally determined that the use of a floating insulation layer at the liquid-gas interface had little effect on overall gas requirements for expulsion.In fact, the use of the b a r r i e r increased pressurant gas requirements slightly.I 7 111.1.111111111111I 1 1 1 1 1 I 1
Authors: R. L. De Witt, W. R. Johnson, R. J. Stochl
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W810404303