Arcjet rocket

About: Arcjet rocket is a research topic. Over the lifetime, 1121 publications have been published within this topic receiving 9687 citations. The topic is also known as: Arcjet.

Thermal Protection System Crack Growth Simulation Using Advanced Grid Morphing Techniques

Abstract: An extension of previous [Titov, E., Zhong, J., Levin, D., and Picetti, D., "Simulation of RCC Crack Growth Due to Carbon Oxidation in High-Temperature Gas Environments," Journal of Thermophysics and Heat Transfer, Vol. 23, No. 3, July-Sept. 2009, pp. 489-501.] modeling of crack damage growth in reinforced carbon-carbon specimens is presented in this work. The specimens were studied in an arcjet and represented a portion of the space shuttle wing [Lewis, R., "Quick Look Report," Atmospheric Reentry Materials and Structures, 2004.] and a high-velocity meteoroid impact [Curry, D. M., Pham, V. T., Norman, I., and Chao, D. C., "Oxidation of Reinforced Carbon-Carbon Subjected to Hypervelocity Impact," NASA TP 2000-209760, March 2000.]. The test geometry and flow conditions rendered the flow regime as transitional to continuum; therefore, a Navier-Stokes-based gas-dynamic approach with the temperature jump and velocity slip correction to the boundary conditions was used. The modeled mechanism for wall material loss was atomic oxygen reaction with the bare, exposed carbon surface. The purpose of this work is to improve the predictive modeling of crack growth damage assessment by developing procedures that use coupled, advanced topology-based surface and grid-meshing tools. A recessing three-dimensional surface morphing procedure was developed and tested by comparison with arcjet experimental results. A multiblock structured adaptive meshing was used to model the computational domain changes due to the wall recession. This approach made it possible to model full three-dimensional crack growth scenarios as well as to include the presence of realistic reinforced carbon-carbon material features such as delamination, both of which affect damage growth because they enable higher atomic oxygen penetration. Comparison with the arcjet data show that the inclusion of these two factors further improves the comparison between modeling and data. The predicted channel growth and shape change were found to agree with arcjet observations, and local gas flowfield results were found to affect the oxidation rate in a manner that cannot be predicted by previous mass loss correlations. The method holds promise for future modeling of materials gas-dynamic interactions for hypersonic flight.

Investigations of advanced medium power hydrogen arcjets

Abstract: The performance of thermal arcjet thrusters has to be improved sign$cantly to remain competitive and to meet the mission requirements for future application. A considerable improvement in specific impulse and thrust eficiency can be realized by recovering the thermal losses using intensive regenerative cooling and by reducing thefrozenflow losses. This paper deals with the basic experimental work which was undertaken at the Institute fiir Raumfahrtsysteme (IRS). Starting with a conventional radiation cooled thruster with a modular design, the baseline anode configuration was modified stepwise by changing the nozzle inserts. The performance and thermal behaviour of these thrusters were investigated in extensive test series operated with hydrogen at power levels of 5 to 12 kW. With the change to a regeneratively cooled nozzle, the thruster became substantially cooler at equivalent specific energy conditions. Thus the recovered energy was converted into thrust and the specific impulse and especially the thrust eficiency could be increased quite impressively. For the latest design approach, the spec$c impulse exceeded 1200 s at a specific power of 180 M J k g and 39 Yo thrust eficiency. Furthermore the comparison of surface temperature distribution provides an impressive insight into cooling processes and provides guidonce for new thruster designs. d