Dynamic characteristics of the recessed chamber within a gas–liquid coaxial injector

In this article, a linear dynamic characteristic model of the recessed chamber in a gas–liquid shear coaxial injector is developed. The gaseous injector flow before the recessed chamber is considered to be steady, and we just investigate the response of pressure drop across the recessed chamber to the mass flow rate fluctuation of the liquid injector. The transfer function of the recessed chamber is obtained, considering the distribute characteristics of liquid droplets within the recessed chamber. The results show that the amplitude of pressure drop pulsation would decrease as the liquid flow pulsation frequency increases, when the variation of liquid velocity is not taken into account. While considering the variation of liquid velocity, the result is opposite. The amplitude of pressure drop oscillation on the boundary of the recessed chamber increases with the increase in liquid velocity oscillation frequency.