Papers by Keyword: Waterhammer

Abstract: The spacecraft propulsion system is used for geosynchronous orbit transfer, three-axis stabilization and station-keeping. In order to investigate the system dynamics of spacecraft propulsion system with complex pressurization pipelines and propellant supply pipelines, a modular and extensible simulator UPSSim was developed. The pressurant pipelines were separated into several nodes, each node used lumped parameter model; while the propellant feed pipelines used distributed parameter model. Heat transfer between components and environment was also taken into account. The model accurately predicts the transient behavior of the spacecraft propulsion system during start-up and shutdown process, as well as the effect of pipe initial pressure on the priming waterhammer amplitude. The simulation result demonstrates the adequacy of the modular modeling methodology for spacecraft propulsion system dynamic simulation.

Abstract: According to the general solution for waterhammer deriving by the author, this paper proved that the solution can be written in the form of the d'Alembert's wave functions. Some equations including the so-called the chain equation is derived with the help of the new solution. The periodical influence of the initial conditions on the results is discussed.

Abstract: The paper has obtained a unified final solution for the waterhammer equations. The proposed solution, covering all kinds of initial conditions and boundary conditions, has been proved to be written in the form of the d'Alembert's wave functions. The periodical influence of the initial conditions on the results is discussed. The proposed solution, with two kinds of algebraic equations containing only finite terms, is suitable for numerical calculation, convenient for programming and liable to dealing with complex pipe systems. An example has been given to show the use of the method. The skill to perform the inverse Laplace transform in obtaining the solution is different from the traditional ones and can be extended to use in many other problems including the FSI waterhammer problem.