Cooling Methods in Combustion
Chambers and Nozzles
Department of Mechanichal Engineering and Aeronautics
John Poulopoulos, Theodoros Chronopoulos
This study is submitted for the project of
Rocket Propulsion Systems
University of Patras 2020
, Abstract
One of the most important problems that can occur in a space propulsion system is that of
heat transfer. The amount of heat generated during the combustion of the propellant in a
rocket engine can seriously damage the materials of the walls of the propulsion chamber.
The present theoretical study probes the cooling methods used in combustion chambers
and rocket engine nozzles. Moreover, the issues of heat transfer in propulsion chambers
are described as well as the materials preferred for the construction of chambers and
nozzles. Finally, scientific data and results are presented from articles and citations that
have resulted from simulations and experiments.
Keywords: Rocket engine, Combustion chamber, Rocket nozzle, Cooling methods,
Aerospace industry
1
,Contents
List of Images ............................................................................................................................. 3
1. Introduction ......................................................................................................................... 4
2. Shape of Thrust Chambers ................................................................................................... 5
3. Heat Transfer to Thrust Chambers ....................................................................................... 6
3.1 Heat Transmission Analysis ......................................................................................... 7
3.2 Heat Transfer to Combustion Chambers and Nozzles ................................................. 10
3.3 Effects of Heat Transfer in Rockets ............................................................................ 11
4. Cooling Methods in Thrust Chambers ................................................................................ 14
5. Cooling with Steady State Heat Transfer ............................................................................ 15
5.1 Regenerative Cooling ................................................................................................. 16
5.2 Radiation Cooling ...................................................................................................... 20
6. Cooling with Transient Heat Transfer ................................................................................ 23
6.1 Heat Sink or Ablative Cooling ................................................................................... 24
6.2 Ablative Materials...................................................................................................... 25
7. Auxiliary Cooling Methods ............................................................................................... 26
7.1 Film Cooling.............................................................................................................. 26
7.2 Thermal Insulation ..................................................................................................... 28
8. Thrust Chamber Wall Materials and Manufacturing ........................................................... 29
9. Scientific Data from Researches ........................................................................................ 33
9.1 Ablative Material Testing for Low-Pressure, Low-Cost Rocket Engines ..................... 33
9.2 Radiative Heating in Combustion Chamber of Liquid Propellant Rocket Engines ....... 35
9.3 Numerical Study of Liquid Film Cooling in a Rocket Combustion Chamber .............. 36
References ................................................................................................................................ 38
2
, List of Images
Figure 1. Thrust chamber of Walter 109-509C rocket engine, 1944. [9] ....................................... 4
Figure 2. Thrust chamber section of the German rocket engine V-2 from WW2. [8]..................... 4
Figure 3. Temperature gradients in cooled rocket thrust chamber, with typical temperatures. [1] . 7
Figure 4. Typical axial heat transfer rate distribution for liquid propellant thrust chambers and
solid propellant rocket engines. [1] ............................................................................................ 10
Figure 5. Typical stresses in a thrust chamber inner wall. [1] ..................................................... 13
Figure 6. Diagram of a tubular cooling jacket. [1] ...................................................................... 15
Figure 7. Cross section of a regenerative cooled thrust chamber. [4] .......................................... 17
Figure 8. Regimes in transferring heat from a hot wall to a flowing liquid. [1] ........................... 18
Figure 9. The two types of double regenerative cooled thrust chambers. [4] ............................... 19
Figure 10. Radiation-cooled reaction control thruster R-4D-15 uses nitrogen tetroxide and
monomethylhydrazine propellants, Courtesy of Aerojet Propulsion Company. [1] ..................... 21
Figure 11. Typical temperature distributions through a wall of an uncooled relatively thick metal
thrust chamber as a function of heating time. [1] ........................................................................ 24
Figure 12. Simplified diagrams of three different methods of forming a cool boundary layer in the
nozzle. [1] ................................................................................................................................. 27
Figure 13. Simplified sketches of sections through a portion of the cooling jacket of several
different cooling schemes in regeneratively cooled thrust chambers. [1] .................................... 30
Figure 14. The RL-10B-2 rocket engine has an extendible nozzle cone or skirt, which is placed
around the engine during the ascent of the Delta III and IV launch vehicles (Courtesy of Pratt &
Whitney Rocketdyne, of United Technologies, Inc.). [1] ............................................................ 32
Figure 15. Photo of test sample U.R. SIL/PHEN before firing (a) and 164 seconds after firing (b).
[5] ............................................................................................................................................. 34
Figure 16. Heat flux distribution on a thrust chamber. [3] .......................................................... 35
3
Chambers and Nozzles
Department of Mechanichal Engineering and Aeronautics
John Poulopoulos, Theodoros Chronopoulos
This study is submitted for the project of
Rocket Propulsion Systems
University of Patras 2020
, Abstract
One of the most important problems that can occur in a space propulsion system is that of
heat transfer. The amount of heat generated during the combustion of the propellant in a
rocket engine can seriously damage the materials of the walls of the propulsion chamber.
The present theoretical study probes the cooling methods used in combustion chambers
and rocket engine nozzles. Moreover, the issues of heat transfer in propulsion chambers
are described as well as the materials preferred for the construction of chambers and
nozzles. Finally, scientific data and results are presented from articles and citations that
have resulted from simulations and experiments.
Keywords: Rocket engine, Combustion chamber, Rocket nozzle, Cooling methods,
Aerospace industry
1
,Contents
List of Images ............................................................................................................................. 3
1. Introduction ......................................................................................................................... 4
2. Shape of Thrust Chambers ................................................................................................... 5
3. Heat Transfer to Thrust Chambers ....................................................................................... 6
3.1 Heat Transmission Analysis ......................................................................................... 7
3.2 Heat Transfer to Combustion Chambers and Nozzles ................................................. 10
3.3 Effects of Heat Transfer in Rockets ............................................................................ 11
4. Cooling Methods in Thrust Chambers ................................................................................ 14
5. Cooling with Steady State Heat Transfer ............................................................................ 15
5.1 Regenerative Cooling ................................................................................................. 16
5.2 Radiation Cooling ...................................................................................................... 20
6. Cooling with Transient Heat Transfer ................................................................................ 23
6.1 Heat Sink or Ablative Cooling ................................................................................... 24
6.2 Ablative Materials...................................................................................................... 25
7. Auxiliary Cooling Methods ............................................................................................... 26
7.1 Film Cooling.............................................................................................................. 26
7.2 Thermal Insulation ..................................................................................................... 28
8. Thrust Chamber Wall Materials and Manufacturing ........................................................... 29
9. Scientific Data from Researches ........................................................................................ 33
9.1 Ablative Material Testing for Low-Pressure, Low-Cost Rocket Engines ..................... 33
9.2 Radiative Heating in Combustion Chamber of Liquid Propellant Rocket Engines ....... 35
9.3 Numerical Study of Liquid Film Cooling in a Rocket Combustion Chamber .............. 36
References ................................................................................................................................ 38
2
, List of Images
Figure 1. Thrust chamber of Walter 109-509C rocket engine, 1944. [9] ....................................... 4
Figure 2. Thrust chamber section of the German rocket engine V-2 from WW2. [8]..................... 4
Figure 3. Temperature gradients in cooled rocket thrust chamber, with typical temperatures. [1] . 7
Figure 4. Typical axial heat transfer rate distribution for liquid propellant thrust chambers and
solid propellant rocket engines. [1] ............................................................................................ 10
Figure 5. Typical stresses in a thrust chamber inner wall. [1] ..................................................... 13
Figure 6. Diagram of a tubular cooling jacket. [1] ...................................................................... 15
Figure 7. Cross section of a regenerative cooled thrust chamber. [4] .......................................... 17
Figure 8. Regimes in transferring heat from a hot wall to a flowing liquid. [1] ........................... 18
Figure 9. The two types of double regenerative cooled thrust chambers. [4] ............................... 19
Figure 10. Radiation-cooled reaction control thruster R-4D-15 uses nitrogen tetroxide and
monomethylhydrazine propellants, Courtesy of Aerojet Propulsion Company. [1] ..................... 21
Figure 11. Typical temperature distributions through a wall of an uncooled relatively thick metal
thrust chamber as a function of heating time. [1] ........................................................................ 24
Figure 12. Simplified diagrams of three different methods of forming a cool boundary layer in the
nozzle. [1] ................................................................................................................................. 27
Figure 13. Simplified sketches of sections through a portion of the cooling jacket of several
different cooling schemes in regeneratively cooled thrust chambers. [1] .................................... 30
Figure 14. The RL-10B-2 rocket engine has an extendible nozzle cone or skirt, which is placed
around the engine during the ascent of the Delta III and IV launch vehicles (Courtesy of Pratt &
Whitney Rocketdyne, of United Technologies, Inc.). [1] ............................................................ 32
Figure 15. Photo of test sample U.R. SIL/PHEN before firing (a) and 164 seconds after firing (b).
[5] ............................................................................................................................................. 34
Figure 16. Heat flux distribution on a thrust chamber. [3] .......................................................... 35
3
