Plasma body force phenomenological model for different altitudes

In order to use the plasma body force phenomenological model to simulate the plasma flow control at different altitudes, if assuming the ion number density was directly proportional to plasma light emission, the relative light intensities of plasma emission and light intensity ratios i.e. ion number densities with gas pressure and applied voltage, were obtained by processing the plasma discharge image to gray scale at varying pressures 101.3-1.5kPa. It was found that when the pressure increased, the discharge became filamentary from diffuse, while the light intensity ratios decreased. The saturated relative light intensity in the atmospheric pressure can be used to represent one in other pressures. When the applied voltage increased, discharge occurred at the double-sides of actuator, and the light intensity increased. The total discharge had a linear relationship with applied voltage. Then the new charges boundary condition was built by theory analysis, and the relative light intensities of several plasma emissions at different gas pressure and applied voltage were fitted. Two typical cases were simulated, and the results were used to compare with the plasma jets at corresponding gas pressures measured by particle image velocimetry. It is shown that the new model can simulate the influences on the plasma jets by flight altitude and applied voltage.