Arc Heater Manifold Evaluation

摘要

Arc heaters are required to provide the high pressure and temperature testconditions necessary to meet critical testing needs for propulsion, materials, and structures. Two configurations can produce the high power arc heater capability required: a single large arc or a multi-arc configuration based on manifolding a number of smaller heaters into a common plenum. Such multi-arc configurations can be a convenient route to high-power heaters (on the order of 200-300 MW), but at the cost of reduced performance because of additional wall cooling losses. A multi-arc configuration may be an effective way to improve flow uniformity of both enthalpy and pressure. The mixing of effluents of separate arc heaters in a single plenum may dampen flow-field fluctuations because oscillations in the individual arc units will probably be totally independent. Experiments were performed to assess the effect of manifolding arc heaters into a single plenum on flow quality and heater efficiency. A reduction in enthalpy of approximately 7 percent was attributed to the manifold. The reduction in enthalpy is caused by the additional wall losses in the manifold. Fluctuations in the flow were slightly better for the multi-arc configuration (compared to a single heater), primarily because of smaller fluctuations in the pressure. Heat flux fluctutations for the multi-arc system were nearly the same as for a single-arc heater.