Cryogenic Pressure Control Modeling for Ellipsoidal Space Tanks in Reduced Gravity

Abstract

A computational fluid dynamics (CFD) model is developed to simulate pressure control of an ellipsoidal-shaped liquid hydrogen tank under external heating in low gravity. Pressure control is provided by an axial jet thermodynamic vent system (TVS) centered within the vessel that injects cooler liquid into the tank, mixing the contents and reducing tank pressure. The two-phase cryogenic tank model considers liquid hydrogen in its own vapor with liquid density varying with temperature only and a fully compressible ullage. The axisymmetric model is developed using a custom version of the commercially available FLOW-3D software and simulates low gravity extrapolations of engineering checkout tests performed at Marshall Space Flight Center in 1999 in support of the Solar Thermal Upper Stage Technology Demonstrator (STUSTD) program. Model results illustrate that stable low gravity liquid-gas interfaces are maintained during all phases of the pressure control cycle. Steady and relatively smooth ullage pressurization rates are predicted. This work advances current low gravity CFD modeling capabilities for cryogenic pressure control and aids the development a low cost CFD-based design process for space hardware.Nomenclature dp/dt = ullage pressure rise rate V max = maximum velocity within the domain

Modeling of Ullage Collapse Within Rocket Propellant Tanks at Reduced Gravity

“…Each method uses Eqs. (9) and (10) to determine the thermal properties at each time step so that the changing ullage temperature affects the evaporation rates. The evaporation time depends on the duration of the time step.…”

“…Previous work focused on improving mission planning capabilities and modeling of orbital maneuver scenarios for rockets has demonstrated a need to accurately model the dynamics and thermodynamics of the fluids inside propellant tanks. Lopez et al [9] developed a CFD model to determine the pressure within an ellipsoidal tank under external heating. Majumdar and Steadman [10] created models to describe the pressure of a tank as propellant leaves the tank.…”

Study on the Self-Pressurization Laws of Cryogenic Liquid Krypton Tank for the Electric Propulsion System

“…To study the self-pressurization behavior in a liquid hydrogen tank under a normal gravity environment, Barsi [15] established a gas-liquid two-phase CFD model in the tank and gave the effect of filling rate on the self-pressurization behavior in a liquid hydrogen tank. Lopez et al [16,17] established a CFD model to study the pressure change and pressure control in spherical liquid hydrogen tanks under different gravity environments. Using a two-dimensional geometric model with rotational symmetry and a 3.5 W/𝑚 2 heat flow boundary, Kassemi et al [18] simulated and examined the selfpressurization process in a zero-evaporation liquid hydrogen tank under normal gravity conditions.…”

Dynamic Behaviors of Liquid in Partially Filled Tank in Short-term Microgravity

“…Storage tank is one of the basic components for spacecraft, in which the behavior of liquid is mostly responsible for the safety, stability, fuel supply, and so on. Correspondingly, researchers pay close attentions to the shape of free surface (Kulev and Dreyer 2010;Park et al 2015;Zhou et al 2016;Zwicke et al 2017), the pressure control inside tank (Lopez et al 2008; Barsi and Kassemi 2013;Chen and Liang 2013;Kassemi and Kartuzova 2016), the liquid sloshing (Zhou and Huang 2015;Deng and Yue 2017), and the measurement of the residual liquid. Among these aspects, the dynamic evolution of the free surface of the liquid inside tank is the key topic, which is principally determined by the surface tension force in microgravity environment.…”