Detonation Temperature for Hydrogen-Oxygen Mixtures Using Multi-wavelength Pyrometer

A multi-wavelength method that can be used to measure the detonation temperature for hydrogen-oxygen mixture in shock tube was described in this paper, with the entire field of view of the receiving fibers either filled by the gases or not. To calculate transverse temperature and longitudinal temperature, the continuum radiation at four wavelengths (406.4, 540, 636, 835 nm) was measured by two ways, one was that the receiving fibers were vertical to the direction of detonation wave, and the other was that the receiving fibers were parallel to the direction of detonation wave. If Planck equation is assumed to be suitable for product gases and the emissivity of the gases is assumed to be gray for the above four wavelengths, the transverse and longitudinal temperatures for six hydrogen-oxygen mixtures were calculated in the initial pressure range 0.020~0.053 MPa and the fitting errors were about 10%. The transverse temperature coincides with the longitudinal temperature in the experimental errors and the temperatures also coincide with the theoretical C-J temperature very well.