Cavitating Venturi Model Using Standard Element and Options in Commercially Available Lumped-Parameter Software

Abstract

Numerous liquid propulsion applications utilize cavitating venturis to provide a passive liquid flow control to the propellants within the system. Selecting the appropriate venturi configuration for the vehicle propellant system often requires multiple experimental iterations which could be decreased if an appropriate dynamic fluid model were developed. As a first step toward the creation of such a model, a cavitating venturi element was developed using a commercially available lumped-parameter software. The two methods used to generate the cavitating venturi model are described and a comparison of the models to experimental data is presented. Nomenclature GSFC= Goddard Space Flight Center SOS = speed-of-sound SwRI = Southwest Research Institute

Dynamic Modeling and Full-Process Simulation of the Core Engine Test Rig Main Test System

“…By using Fluent 15.0 to conduct steady-state computation for the triple eccentric butterfly valve, Sun et al [18] discovered that the surface roughness may result in a big difference between the flow coefficient obtained by simulation without friction and the actual flow coefficient. The second type of research [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] focuses on the whole system rather than the valve, and thus generally uses the traditional 0D throttling flow-rate equation instead of the momentum equation to describe the dynamic throttling effect of the valve spool. In order to accurately describe the throttling effect, this simplified modeling method must take flow-rate equation, flow coefficient calculation, and valve-spool opening and closing rule into full consideration.…”

“…Firstly, as the core of the throttling model, the valve-spool or orifice throttling flow-rate equation is a semi-theoretical and semi-empirical formula. By the form of relationship between the flow rate and the upstream and downstream pressures, it can be roughly divided into the pressure ratio-based form [15,24,25] and the pressure difference-based form [15,[27][28][29][30][31][32][33][34][35][40][41][42]. The former generally applies to the condition of gas flow medium while the latter usually applies to the condition of liquid flow medium.…”

“…The second type of simulation research covers both the information-known valves [15,25,[27][28][29][30][31][32][33][34][35][36] and the information-unknown valves [25,37,38,42], as well as the throttling devices, such as some orifices [39] or Venturi tube [40], and can be divided into the following three cases by the valve opening in the experimental process:…”