rocket engine transient simulations - msc software corporation

EASY/ROCETS Dynamic Fluid Flow SimulationP ackage

Randolph F. FollettDepartment of Electrical and Computer Engineering

Mississippi State UniversityMississippi State, MS 39762

Phone: (662)-325-3073 Email: [email protected]

Presented at the EASY5 User Conference, May 16-17, 2000

Introduction

The EASY/ROCETS Cryogenic Flow Modeling Environment

P Background - Part of the technical support for the Component TestFacility (CTF) (a.k.a. the E1 Test Stand) Dynamic Fluid Flow Modelingprogram for NASA/Stennis Space Center (SSC).

P Objective - Complete computational models for dynamic fluid flowsimulations to produce accurate predictions of pressures, temperatures,flow rates, etc., with particular focus on cryogenic fluids used in groundtesting of rocket engine components.

P Composition -< ROCETS - (ROCet Engine Transient Simulator) 1-D rocket engine

simulation package developed by Pratt and Whitney GovernmentEngines Business (United Technologies Corp.) specifically forNASA’s use

< EASY5x


ROCETS Paradigm

PROCETS was developed for NASA’s use insimulation of rocket engines (either complete orpartial)

P It uses a centralized integration scheme (muchlike EASY5) with “engineering modules” thatmatch well with “components”. Thesecomponents already model many of the enginecomponents of interest to NASA.

PUser interface is text-based rather than a GUI

PNo built-in graphing capability


ROCETS Engineering Modules

PPipe modules - model flow resistance< PIPE00 - pipe with an inertial loss< PIPE01 - incompressible flow with a loss< PIPE02 - compressible fluid flow through an orifice< PIPE03 - incompressible flow with a loss, inertia, and

change in elevation

PVolume modules - model flow capacitance< VOLM00 - energy and continuity analysis of a volume

with one inlet flow, one exit flow, and one heat flow< VOLM01 - 4-inlet, 4-exit version of VOLM00


ROCETS Engineering Modules

PMiscellaneous modules:< VALV00 - Calculates incompressible fluid flow

through a valve using linear flow correlations< INLET and EXIT - set boundary conditions using

enthalpy and pressure< PUMP01 - constant density pump< TURB01 - isentropic analysis of a turbine driven by an

ideal gas< ROTR - calculates rotor speed derivative


MSU-created Engineering Modules

PBOTL00 - energy and continuity analysis of anadiabatic bottle with one exit mass flow

PTANK00 - tank analysis incorporating mixed-state analysis (vapor on top, liquid on bottom)

PRTANK - models the dynamics of a run tankpressurization with vapor ullage

PVENT99 - gas venturi flow calculation

PVarious pipes, valves and a valve-pipe


MSU-created Engineering Modules

PPS - incompressible fluid flow through a pipewith a screen and a loss

PPLC’s - models of Allen-Bradley PLC-5 andSLC-500 PID controllers

PSR - sequencer for multi-valve control withevent-based or time-based actuation


Example System Analysis

High-Pressure Hydrogen Subsystem of E1 Test Stand at SSC



Run Tank Pressurization Controller (RTP)



Mass Flow Controller (LHF)



Temperature Controller (TC)


Results

Presented at the EASY5 User Conference, May 16-17, 2000EASY5 BOEING

0 20 40 60 80 1000

2000

4E+3

6E+3

8E+3

Time

ScheduledActual

Results


EASY5 BOEING

0 20 40 60 80 1000

100

200

300

400

0 20 40 60 80 100-10

0

10

20

30

40

Time

Time

ScheduledActual

ScheduledActual

Conclusions

PROCETS provides a good basis for building acryogenic fluid flow analysis package

PEASY5x provides the GUI and superiorintegration engine

PEASY/ROCETS allows effective simulations tobe created by “non-experts” (in simulation) andallows the user to focus on results

PAcknowledgements: < NASA Stennis Space Center (SSC)< Lockheed Martin Space Operations (at SSC)


rocket engine transient simulations - msc software corporation

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