Results of both experimental and three-dimensional numerical studies on H 2 /air continuous rotating detonation are presented. Tangentially injected H 2 /O 2 hotshot jet was used to ignite the engine successfully. Under the condition of air and hydrogen mass flow rates of 265 and 7.7 g/s and the ambient pressure of 11 kPa, H 2 /air continuous rotating detonation has been realized for about 300 ms. Time-frequency characteristics of the measured results were analyzed by different methods, and the results agreed well with each other. The detonation wave propagated stably during the test, with the propagation frequency variation of 5.35-5.85 kHz. The mean propagation velocity was 1674.3 m/s, which was about 85.0% of the theoretical value. Corresponding three-dimensional numerical simulation was carried out. Flow field structure of the rotating detonation wave was analyzed, and the curvature effect was also considered. Propagation processes of both the experiment and simulation results were compared. The variation of detonation wave propagation frequency of the simulation case was 6.262-6.27 kHz, with the mean propagation velocity of 1870.1 m/s, which was larger than the experiment result. Distribution of the mean combustor pressure along the axis direction was analyzed. Within the heat release zone, the mean pressure decreased greatly, and it changed gently beyond this zone. The changing tendency of both the experimental and numerical results agreed with each other, but there were differences between the pressure values.

The monitoring of a progressive collapse test of a structure model has always been a technical issue in civil engineering. This paper proposes a novel videogrammetric approach to monitor a single-layer lattice shell, which consists of three main parts:(1) A videogrammetry system with six high-speed cameras is established to measure the morphological changes of the lattice shell.(2) A specific artificial target is designed and experimentally tested to obtain the location of every node centre on the lattice shell. (3) The 3D displacements of the node centres can be calculated by surface fitting and local coordinate transformation. The proposed approach can achieve sub-millimetre discrepancies in the position of the artificial targets compared with high-accuracy total station results, and the locational discrepancy of the node centres can reach about one millimetre. The credibility of the measured displacement results is further verified by comparison with a numerical simulation of the model collapse.

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