MHD T-Burner Combustion Response Test Improvements

MHD (magnetohydrodynamic) instrumentation was installed on the 36 inch T-burner for simultaneous measurements of pressure coupled response and h@lD velocity field oscillation measurements. Tests have been done at pressures of 200,300, and 1000 psia using pellets of AP, HMX, and RDX and AP/HTPB propellants BP4, 3%HMX, 3%UFAL and PBAN/AP. Recent improvements include a 3800 gauss permanent magnet, high impedance preamps, capacitors on inputs leads as high pass filters, Autolite spark plug probes, and ceramic liner in pipe. It was hoped that these improvements would produce larger MHD electrode voltages, but apparently good electrical insulation from the wall is still required. Phenolic liners will be inserted in future tests. Probe 1, nearest the sample, generally had the highest signal levels (except when it shorted out), but not the same frequency as the pressure oscillation. Oscillation levels were strongest for the AP pellets. It was expected that the phase lags for the probes would be closer together than they were.