Rocket Thermal Evaluation

RTE is a comprehensive Rocket Thermal Evaluation computer code developed for NASA Lewis Research Center, presently Glenn Research Center. The early version of the code was distributed through NASA's COSMIC Library. For a brief slide presntation of this code with some sample results click on this text.


RTE (Rocket Thermal Evaluation) is  a computer code for three-dimensional thermal analysis of regeneratively cooled rocket thrust chambers and nozzles. A unique feature of this code is conjugating all thermal/fluids processes in the propulsion system in order to obtain matched results for the thermal field. These thermal/fluids processes include: convection and radiation heat transfer from hot combustion gases to the liner of the engine; conduction heat transfer with walls; and convection to the coolant. RTE uses an iterative marching scheme to match the heat flux and temperature fields of these thermal processes. The program uses GASP (GAS Properties), WASP (Water and Steam Properties) and a module for properties of RP1 to evaluate coolant flow properties. Hence, it is capable of handling all commonly used coolants in propulsion systems (e.g., H2, O2, H2O, CH4, RP1, H2O2). CET (Chemical Equilibrium with Transport Properties) code is used for evaluation of hot gas properties. The inputs to RTE consist of the composition of fuel/oxidant mixtures and flow rates, chamber pressure, coolant entrance temperature and pressure, dimensions of the engine, materials and number of nodes in different parts of the engine. It allows temperature variations in axial, radial and circumferential directions and by implementing an iterative scheme, it provides a listing of nodal temperatures, rates of heat transfer, and hot-gas and coolant thermal and transport properties. The O/F (oxidant/fuel) ratio can be varied along the thrust chamber. This feature allows the user to incorporate a non-equilibrium model or an energy release model for the hot-gas-side. The mixture ratio at each station can be calculated using ROCCID. Thermal radiation from hot gases within the chamber is also included in the analysis. The exchange factors for radiation calculations are evaluated using an external module (RTE_RAD, Rocket Thermal Evaluation Discrete Exchange Factor), which can be input to the main rocket thermal evaluation code.

This code can be used for both regeneratively and radiatively cooled engines. For regeneratively cooled engines, the code can be used for one pass as well as pass-and-half cooling cycles. Additionally, the blocked channel option allows a user to assess the thermal performance of a regeneratively cooled engine when a cooling channel is blocked. The user has the option of bypassing the hot-gas-side calculations and directly inputting gas side fluxes. This feature can be used to link RTE to a boundary layer program for the hot-gas-side heat flux calculation. The procedure for linking RTE to a hot-gas side program, TDK (Two Dimensional Kinetics Nozzle Performance Computer Program) is described in this manual.

To ease inputting the large data sets needed to run the program a Graphic User Interface (preprocessor) based on Excel is provided. A user can fill in engine specifications in designated Excel cells and choose the right engine information from combo boxes. Then by clicking on a command button, data from the Excel interface would be transferred into RTE’s input file.  For a trial version of RTE's GUI click on this text. RTE provides a number of output files, each provide useful information regarding the engine’s thermal performance. The Graphic postprocessor of RTE is based on Excel and Techplot software. It produces a number of output files that can be processed by both Excel Tecplot for temperature isotherms and graphic results.

To learn more about Thermal Analysis of Regenenratively Cool Rocket Engines you may enroll in the AIAA webinar on Thermal Modeling and Regenerative Cooling of Rocket Engines.

More detailed information on this program can be obtained from the following publications:

•      DiValentin, J., Naraghi, M.H., “Effects of Cooling Channel Curvature and Aspect Ratio on the Coolant Secondary Flow and Heat Transfer,” to be presented at the 46th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Nashville, Tennessee, July 25-28, 2010. 

•      Jokhakar, J and Naraghi, M.H., “A CFD-RTE Model for Thermal Analysis of Regeneratively Cooled Rocket Engines,” AIAA paper 2008_128137, presented at the 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Hartford, CT, July 21-23, 2008. 

•      Foulon, M., and Naraghi, M.H., “A Simple Approach for Thermal Analysis of Regenerative Cooling of Rocket Engines,” ASME paper IMECE2008-67988, presented at the International Mechanical Engineering Congress, October 31-November 6, 2008. 

•      Naraghi, M.H.N., Dunn, S., and Coats, D., ”Dual Regenerative Cooling Circuits for Liquid Rocket Engines,” AIAA-2006-4367, presented at the AIAA Joint Propulsion Conference,  Sacramento,  California , July 2006.

•      Naraghi, M.H.N., Dunn, S., and Coats, D.,  “Modeling of Radiative Heat Transfer in Liquid Rocket Engines,” AIAA-2005-3931, presented at  the AIAA Joint Propulsion Conference,  Tucson, Arizona, July 2005.

•      Naraghi, M.H.N., Dunn, S., and Coats, D., “A Model for Design and Analysis of Regeneratively Cooled Rocket Engines,” AIAA-2004-3852, presented at the AIAA/ASME/ASEE Joint Propulsion Conference, Fort Lauderdale, Florida, July 11-14, 2004. 

•      Naraghi, M.H.N., ``RTE - A Computer Code for Three-Dimensional Rocket Thermal Evaluation," User Manual, 2002.

•      Naraghi, M.H.N., ``RTE - A Computer Code for Rocket Thermal Evaluation," presented at the 1994 Thermal and Fluid Analysis Workshop, Cleveland, Ohio, August 15-19, 1994.

•      Hammad, K.J., and Naraghi, M.H.N., ``Radiative Heat Transfer in Rocket Thrust Chambers and Nozzles,'' AIAA paper 89-1720, presented at the 24th AIAA Thermophysics Conference in Buffalo, New York, June 12-14, 1989; also AIAA Journal of Thermophysics and Heat Transfer, Vol. 5, No. 3, pp. 327-334, 1991.

•      Naraghi, M.H.N., and Armstrong, E.S., ``Three Dimensional Thermal Analysis of Rocket Thrust Chambers,'' AIAA paper 88-2648, presented at the AIAA Thermophysics, Plasmadynamics and Lasers Conference, San Antonio, Texas, June 27-29, 1988.

•      Naraghi, M.H.N., and DeLise, J., `` Conjugate Conductive, Convective and Radiative Heat Transfer in Rocket Engines," ASME publication HTD-Vol. 307, pp. 65-79, Preceding of the 30th National Heat Transfer Conference, Portland, Oregon, August 6-8, 1995.

•      Delise, J.C., and Naraghi, M.H.N., ``Comparative Studies of Convective Heat Tranfer Models for Rocket Engines,'' AIAA paper 95-2499, presented at the 31st AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, San Diego, CA, July 10-12, 1995.

•      Naraghi, M.H.N., Quentmeyer, R.J. and Mohr, D.H., "Effect of a Blocked Channel on the Wall Temperature of a Regeneratively Cooled Rocket Thrust Chamber," AIAA paper 2001-3406, presented at the 37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Salt Lake City, UT,  July 8-11, 2001

  If you are interested in obtaining a copy of the code please send an e-mail to:


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