LRE System Analysis

LRE System Analysis

The use of system modeling tools for design and analysis of liquid rocket engines is necessary during the predesign activities. A system approach has to be used, since it is necessary to take into account the interactions between all components of an engine. In this framework, the research activities focus on development of low-order models for the simulation of the hydraulic and thermal characteristics of LRE components, in the context of the EcosimPro/ESPSS modeling tool.        

EcosimPro is an object-oriented visual simulation tool capable of modelling various kinds of dynamic systems, while the European Space Propulsion System Simulation (ESPSS) consists of multiple EcosimPro libraries able to represent a functional propulsion system (Fig. \ref{fig:ESPPS_pressure_fed}), e.g. fluid properties, pipe networking including multi-phase fluid Flow, two-phase two-fluids tanks, non-adiabatic combustion chambers, chemistry, turbomachinery, etc.

Such modeling tool allows to perform analysis of propellant chemical and fluid dynamic behavior through the entire propulsion system, from the tanks through the connecting pipes, valves, manifolds, combustion elements, and nozzles, which are usually described with 1D/2D models. 

Several improvements in the modeling have been performed by the research team in several components, including pipes, combustion chambers, cooling channels and pumps, both in the transient libraries, which can be used to simulate all engine working phases, including start-up and shut-down, and the steady-state libraries, which instead allow to perform parametric calculations and engine design. Some of the most relevant activities performed over the years are listed below:

• Implementation of advanced numerical schemes and introduction of a stratified flow model for two-phase flow analysis for the fluidic line components

•  Improvement of the numerical approach, implementation of heat transfer correlations and development of film-cooling sub-models for the combustion chamber 

•  Development of thermal network models for LRE injection plates and cryogenic pumps

• Implementation of nozzle erosion models  for hybrid and solid rockets