Problem Types
NASA CEA Tutorial
Rocket
Examples
References
Timothée Pourpoint
1
Online Access & Documentation
http://www.grc.nasa.gov/WWW/CEAWeb/ceaWhat.htm
CEA:
• calculates chemical
equilibrium product
concentrations
• determines thermodynamic
& transport properties
2 supporting documents:
Request a
download
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1. Detailed analyses of
chemical equilibrium
calculations
2. User manual and
program description
Installation Overview
Download desired version (Windows)
CEA GUI Download consists of the following files:
1) CEAgui-jar.zip
2) CEA+Fortran.zip
3) CEAexec-win.zip
Notes from: Readme_CEAgui-win.txt
If your local system has NOT installed the Java2 SDK (J2SDK), you must install the Java 2 Runtime
Environment (JRE) which consists of Java Virtual Machine, the Java platform core classes, and
supporting files. It is the runtime part of the J2SDK. j2re1_4_1_03-windows-i586.exe can be downloaded
from "http://java.sun.com/j2se/1.4/" for Java2 SDK from Sun Microsoft Inc.
The CEAexec Package installation procedures for Windows:
1. Create the installation Directory on your local machine (e.g. mkdir C:\CEAexec)
2. Download all three ZIP files and the executable file into the SAME directory (e.g. cd C:\CEAexec)
3. Unzip the Fortran Source Code (CEA+Fortran.zip) and save into the SAME directory.
4. Unzip the CEA GUI Execution file(CEAexec-win.zip)and save into the SAME directory.
5. Unzip the CEAgui JAR file (CEAgui-jar.zip) and save into the SAME directory.
6. Double-click on the file (j2re1_4_1_03-windows-i586) to install Java Runtime Environment (JRE) by
using the system DEFAULT directory (e.g. C:\Program Files\Java Soft\JRE\1.4)
7.Execute the batch file (CEAexec-win.bat) for using the file CEAgui.jar.
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Problem Types (1/2)
Assigned Temperature and Pressure – tp
Chemical equilibrium composition and properties will be calculated for selected temperatures
and pressures.
Combustion (Enthalpy and Pressure) – hp
Enthalpy held constant resulting in an adiabatic flame temperature, equilibrium mixture
properties and composition.
Assigned temperatures and volumes – tv
Chemical equilibrium composition and properties are calculated for assigned temperatures and
a set of either assigned specific volumes or densities.
Combustion (Internal energy and volumes) – uv
Chemical equilibrium composition and properties are calculated for assigned internal energies
and assigned total reactant specific volumes or densities.
Rocket – rkt
Theoretical rocket performance parameters can be calculated for:
infinite-area or finite-area combustors
chemical equilibrium for all points or freeze composition after
combustion, throat, or any exit point.
thermal transport properties
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Problem Types (2/2)
Shock tube – shock
Calculates shock properties in terms of assigned velocities.
Chapman-Jouquet detonation – det
Chapman-Jouguet detonation properties are calculated for a set of unburned gaseous reactants
at assigned temperatures and pressures.
Assigned entropy and pressures – sp
Converges on both the gaseous and condensed products for a reactant mixture with an
assigned entropy and set of pressures.
Assigned entropy and either specific volumes or
densities – sv
Chemical equilibrium composition and properties calculated for assigned
entropy and each assigned total reactant specific volume or density.
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Rocket Problems
INFINITE-AREA COMBUSTOR
All points are isentropic with respect to the combustion point.
Can assume chemical equilibrium or products frozen after a specified point.
Freeze points selections are combustion, throat, or exit1.
FINITE-AREA COMBUSTOR
In this chamber combustion is a
non-isentropic, irreversible process.
During the burning process, part of the
energy released is used to raise the
entropy, and the pressure drops.
Expansion in the nozzle is assumed
to be isentropic.
Can only assume chemical equilibrium.
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Example
Continue with our example from class:
Oxidizer: O2(l)
Fuel: CH4(l)
Pc = 1000 psi
O/F = 4.0 (near stoichiometric)
Ac/At = 3.0
Ae/At = 10.0, 25.0, 50.0
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Inputs to Example (1/4)
Problem Tab
Click
Notes:
1. Make sure all inputs are validated by clicking outside of input cells
2. Make sure there is no space before an input
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Inputs to Example (2/4)
Reactant Tab
Reactant Selector
Notes:
1. Propellants can be in gaseous, condensed (solid/liquid), or atomic form
2. Use the search function to quickly find desired propellant
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Inputs to Example (3/4)
Output Tab
Thermal transport properties are
very useful for calculations related
to cooling requirements in chamber
or at nozzle throat.
Parameters typically used in Bartz
equation (Ref. 3):
Output properties from CEA
include:
• Viscosity [millipoise]
• Specific heat, [kJ/kg-K]
• Thermal conductivity, [mW/cm-K]
• Prandtl number
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Inputs to Example (4/4)
Save input file (File, Save)
View input file
Click on “Activity”
Click on “View Current INPUT file
Ctrl+I”
RUN CEA2
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Output from Example (1/3)
Equilibrium
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Frozen
Output from Example (2/3)
Equilibrium
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Frozen
Output from Example (3/3)
Equilibrium
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Frozen
References
Computer Program for Calculation of Complex Chemical Equilibrium
Compositions and Applications I. Analysis,
Sanford Gordon and Bonnie J. McBride, National Aeronautics and Space
Administration - Lewis Research Center, NASA RP-1311
Computer Program for Calculation of Complex Chemical Equilibrium
Compositions and Applications II. User's Manual and Program Description,
Bonnie J. McBride and Sanford Gordon, National Aeronautics and Space
Administration - Lewis Research Center, NASA RP-1311-P2
Modern Engineering for Design of Liquid-Propellant Rocket Engines, Dieter
K. Huzel and David H. Huang, Progress in Astronautics and Aeronautics,
Volume 147, AIAA
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