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利用能量方程中的源项模拟电火花能量的输入,数值模拟了火花型合成射流激励器的流场,获得了激励器的能量蓄积、喷射和吸入过程.结果表明:电火花瞬间能量的输入产生了腔体内的高温、高压环境,从而诱发合成射流的形成;在周期性激励下,合成射流在3个周期后稳定,喷口处的速度呈现非正弦的周期性变化,射流喷射过程时间极短,吸入外界环境气体的过程时间较长,与压电式合成射流明显不同;喷口下游周期性出现的涡对强度大、卷吸能力强.在输入能量和腔体体积不变时,喷口速度随激发频率的增加,先增加后减小,存在最佳激发频率.激发频率的增加缩短了腔体内气体的冷却时间,实验时对激发频率的选取要考虑腔体的耐温能力.
Using the source term of the energy equation to simulate the input of EDM energy, the flow field of the spark-type synthetic jet actuator is numerically simulated and the energy accumulation, injection and inhalation of the actuator are obtained. The results show that the instantaneous input of EDM energy The high-temperature and high-pressure environment in the cavity can induce the formation of synthetic jets; under the periodic excitation, the synthetic jets are stable after 3 cycles, the non-sinusoidal periodic changes of the jets speed, the very short jet injection time, Inhalation of ambient air takes longer time, which is obviously different from that of piezoelectric synthetic jets. The periodically vortex-induced vortex at the downstream of the nozzle is strong and its entrainment ability is strong. When the input energy and cavity volume are constant, The increase of the frequency firstly increases and then decreases, and the optimal excitation frequency exists.The increase of the excitation frequency shortens the cooling time of the gas in the cavity, and the selection of the excitation frequency in the experiment should consider the temperature resistance capability of the cavity.