SPECIFIC IMPULSES FOR CONTINUOUS DETONATION OF METHANE/HYDROGEN-AIR MIXTURES

Regimes of continuous spin detonation (CSD) with transverse detonation waves (TDWs) are obtained in a flow-type annular cylindrical combustor DK-500 for fuel-air mixtures (FAMs) with two compositions of the binary fuel CH4 + 8H2 and CH4 +4H2. Regimes of continuous multifront detonation (CMD) with colliding TDWs are obtained for the FAM with the CH4 + 2H2 binary fuel. These regimes are characterized by significant irregularity of the TDW structure and by a comparatively low TDW velocity. Specific impulses in continuous detonation are determined and analyzed for different compositions of the methane/hydrogen binary fuel. The maximum measured values of the specific impulse at the combustor exit are approximately 3800 s in CSD of CH4 + 8H2 and CH4 + 4H2, 3200 s in CMD of CH4 + 2H2, and 1600 s in combustion of CH4 + H2.

The Basic Results on Reinitiation Processes in Diffracting Multifront Detonations. Part I.

The basic results of experimental investigations on reinitiation processes in diffracting multifront detonation wave (DW) are discussed in connection with problem of practical application of new ecological technology for worn-out tire destruction, where the cooled worn-out tire destroys with the help of gaseous detonation. The experimental results for various fuel-oxygen and fuel-air mixtures are presented at wide range of mixture compositions, initial pressure and temperature, geometrical sizes of experimental equipment, symmetry types, dilution of inert gases, etc. Classical and nontraditional schema of DW-diffraction are investigated, such as multipointed initiation, DW-excitation by circular charge, initiation space-oriented longitudinal charges, initiation by circular charge, diffraction on concave boundary, diffraction on contact surface of different mixtures, flame diffraction, etc. The main characteristic parameters are identified for each diffraction schema. The physical processes taking place directly in the DW-front plays the governing role in reinitiation. The most important among these processes are collisions of transverse waves, which stick out as microscopic initiators. The optimization problem of DW-initiation from spatial and temporary distribution of energy is discussed carefully. This data can be used at hazard estimation also.