Effect of structure parameter on nozzle performance of bubbly water ramjet engine

To obtain the influence of the nozzle structure parameter to the thrust and efficiency for bubbly water ramjet engine, critical bubbly flow through converging-diverging nozzle was studied numerically with two-fluid model and variable step Runge-Kutta scheme. The results agree well with the experiment. The impact of area ratios (throat to inlet area A_t/A₀), half diverging angle (β) and half converging angle (α) to the thrust and efficiency were investigated by comparing the simulation results. Different mass flow rate ratio (μ) was considered. With increasing the area ratio A_t/A₀, the thrust decreases rapidly but the efficiency increases. The increase in half diverging angle β reduces the thrust and efficiency. The impact of α to the thrust and efficiency is minor. In a certain nozzle, greater thrust and efficiency can be achieved by increasing μ.