Development of Pulsed Arc Heater for Small Hypersonic High-Enthalpy Wind Tunnel

Abstract

A pulsed arc heater was designed, manufactured, and installed in Centrospazio laboratory to equip a newly developed hypersonic, high-enthalpy, small-scale blowdown wind tunnel. The facility operates with air in the low to medium Reynolds number range (10 4 -10 6 ) and is capable of producing Mach 6 air ows, with a speci c total enthalpy up to 3 MJ/kg, on a 60-mm effective diameter test section. The heater is run in a pulsed, quasisteady mode, with test time ranging between 10 and 50 ms. The ow is directly heated by the electric arc established between two coaxial electrodes, powered by a large capacitor bank. A suitable plenum chamber placed just downstream of the discharge chamber allows the ow to reach thermochemical equilibrium before the expansion in the wind-tunnel nozzle and enhances mixing, thereby reducing radial gradients. A numerical model was developed to simulate the unsteady gasdynamic behavior of the arc heater and was used during the design phase to optimize the geometric and temporal parameters of the heater and to assess the hypersonic tunnel useful test time. Experimental results compare favorably with numerical predictions, with the plenum pressure history matching within 5% and plenum temperature within 10%. More than 600 runs have been performed so far, demonstrating the heater reliability and capabilities.

Enhancing the Supersonic Wind Tunnel Performance Based on Plenum Temperature Control

“…Obviously a heater downstream of the storage tank could be designed to yield essentially zero temperature drops, and such heaters are sometimes employed. In this regard, the controlled flow stagnation temperature in the heater output is presented as [9]…”

Exploration of a micro multi-electrode technology applied in an air arc heater

“…An arc heater can heat the air to 2000-7000 K by generating an arc between a cathode and an anode. The high enthalpy air is ejected from a nozzle to simulate the aerothermal environment of the probe reentering the atmosphere [7]. However, the main problem with arc heaters is cathode erosion.…”

Arc spot formation conditions and influencing factors of a micro multi-electrode technology

“…An arc heater can heat the air to 2000-7000 K by generating an arc between the cathode and the anode. The heated air can simulate the aerothermal environment of the probe reentering Earth's atmosphere [7]. However, in order to simulate the aerothermal environment of the probe reentering Earth's atmosphere, the arc heater usually discharges at a current of 3000 A and pressure of 4 MPa so that the cathode is seriously ablated [8,9].…”