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In order to investigate the effects of gas mixture components on the combustion characteristics of rotating detonation wave, two-dimensional simulation is presented to simulate the propagation process of rotating detonation wave with different methane conversions. The results indicate that there are five propagation modes of rotating detonation wave with different components: single-wave mode, single wave with counter-rotating components mode, double-waves mode, triple-waves mode and quadruple-waves mode. The detonation wave propagates along the forward direction in all five modes. With the increase of methane conversion, multi-wave mode appears in the combustion chamber. The fuel component has a great influence on the heat release ratio of detonation combustion. The velocity of detonation wave decreases with the increase of methane conversion. With the increase of methane conversion, the chemical reaction rate gradually increases, which leads to the intensification of chemical reaction on the deflagration surface. The reaction on the deflagration surface develops to the unburned fuel zone, which eventually leads to the formation of compression waves and shock waves in the fuel refill zone. When the shock wave sweeps through the fresh premixed gas, the reactant is compressed to form a detonation point and then ignite the fuel. A new detonation wave is finally formed. The total pressure ratio decreases with the increasing methane conversion, and the uniformity of the total pressure of outlet decreases with increasing methane conversion. • Component change of multicomponent mixture dictate propagation mode. • The influence of component change on detonation wave velocity and pressure is revealed. • The effect of deflagration surface reaction on the characteristics of detonation wave is analyzed. • Pressure ratio of combustion chamber with mixture of different components is compared. [ABSTRACT FROM AUTHOR]

A Ho:SSO crystal was employed as an efficient saturable absorber Q switch for the pulsed Ho:YAG laser for the first time. The characteristics of the passive Q-switch Ho:YAG laser were studied with different incident pump power and different laser energy density around the Ho:SSO. The single pulsed energy varied from 8.3 μJ to 76.6 μJ with the increasing of the incident power from 2.2 W to 8.2 W. The maximum repetition rate was 42.1 kHz, and the minimum pulsed duration was 48 ns. The maximum single-pulse peak power was 1.53 kW. The output center wavelength shifted from 2090.1 nm (the continuous-wave mode) to 2091.3 nm (the passive Q-switch mode). [ABSTRACT FROM AUTHOR]

Represented here is an electron-optic Q switch Ho:ScSi 2 O 5 laser. A RTP crystal was employed as the Q-switch element. It is the first time to demonstrate an electron-optic Q switch Ho:ScSi 2 O 5 laser, whose maximum single-pulse energy reaches around 102 mJ, corresponding to a maximum peak power of 2.91 MW. The laser performance is investigated as a function of the different repetition frequencies and incident pump power. We focus on the low frequencies (1, 2, 5, 8, 10, and 20 Hz) in this contribution, aiming to obtain a higher single-pulse energy. The beam quality M 2 factor of the electron-optic Q switch Ho:ScSi 2 O 5 laser is measured by knife-edge method, which is calculated to be 1.24. [ABSTRACT FROM AUTHOR]