Development of a heat-driven pulse pump for spacecraft applications. II

As mentioned in part I of this paper, one serious deficiency when dealing with one or two-phase flow spacecraft systems, such as thermal control systems, is the existence of a long-lived high-reliability pump. The heat driven pulse pump (HDPP) consists of a grooved cylinder, two check valves, a wick and two strip heaters. Three pumps are installed in parallel to provide a continuous flow rate. When heated, the working fluid, ammonia, vaporizes and produces the pumping pressure head. With only two simple moving parts, the HDPP should function over the long lifetimes required by current spacecraft without maintenance or replacement. This paper provides the results of a second series of tests that were performed after developing an automated control system. These included the effect of sink temperature, the maximum allowable power to the pumps, the influence of the reservoir on flow rate oscillations and the effect of the timing sequence on flow rate oscillations