|
In quest of better propulsive efficiency for the gas-
pressured waterjetrocket , first we must establish genuine
propulsive theoretical fluid dynamics analysis methods. In this
paper , we generally refer Lagrangian Reynolds transport
equation and propulsion power equations developed by Hsing-Juin
Lee to analyze the propulsion theory of gas-pressurized waterjet
rocket.The traditional scheme of high speed exit jet flow to
increase waterjet thrustwill usually involve large kinetic
energy loss. We propose to diverge thewaterjet nozzle to
increase the outlet pressure. In that sense , we use
theturbulent model to calculate the velocity and pressure fields
of waterjet nozzle flow. The velocity flow field of divergent
nozzle often blends with secondary back flows to form velocity
distribution like a maxican chapeau.Therefore , an overly
diverged nozzle cannot ensure upswing for the thrustof a
waterjet rocket rocket. While carrying out the numerical
analysis of thedivergent nozzle and convergent nozzle with 6.5
angle shows better performance. Meanwhile , we may also change
the inlet flow or rocket velocities to upgrade its propulsion
efficiency. In practical design of awaterjet rocket , we may try
to match the rocket system parameters with the fluid pressure ,
nozzle size , curvature , and etc., in order to improve its
propulsive efficiency.
|