The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Mehdi Abarham - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Vortex Flow on Heat Transfer to Combustion Chamber Wall
    Journal of Engineering for Gas Turbines and Power, 2006
    Co-Authors: A. Ghafourian, M. H. Saidi, Saeed Jahangirian, Mehdi Abarham
    Abstract:

    A new experimental facility was designed, fabricated, and tested to model and study the effect of bidirectional swirl flow on the rate of heat transfer to combustion Chamber Walls. Reduction of this heat transfer can result in time and cost of design and fabrication methods of combustion Chambers. The experimental study was performed using propane and air with oxygen as fuel and oxidizer, respectively. For similar flow rates, in cases where bidirectional flow was present, Wall temperature reductions of up to 70% were observed. In cases where only some of the oxidizer was injected from the Chamber end to generate the bidirectional swirl flow, the lowest Wall temperature existed. This can be due to better mixing of fuel and oxidizer and absence of hot spots in the combustion core.

  • Effect of Vortex Flow on Heat Transfer to Combustion Chamber Wall
    Energy Conversion and Resources: Fuels and Combustion Technologies Energy Nuclear Engineering, 2004
    Co-Authors: Saeed Jahangirian, A. Ghafourian, Mehdi Abarham, M. H. Saidi
    Abstract:

    A new experimental facility was designed, fabricated and tested to model and study the effect of bidirectional swirl flow on the rate of heat transfer to combustion Chamber Walls in many applications. Heat transfer to combustion Chamber Walls is an unwanted phenomenon. Reduction of this heat transfer can result in time and cost saving methods in design and fabrication of combustion Chambers. The experimental study was performed by using propane and air with oxygen as fuel and oxidizer respectively. The location of injection ports and geometry of combustion Chamber are flexible and could be varied. Tests were performed with different mass flow rates of fuel and oxidizer. For the same flow rates and with the presence of bidirectional flow, a Wall temperature reduction of up to 50% was observed. In cases where only some of the oxidizer was injected from the Chamber end to generate the bidirectional swirl flow, highest efficiency and lowest Wall temperature existed. This can be due to better mixing of fuel and oxidizer and absence of hot spots in the combusting core. Further development of this technique enables combustion Chamber manufacturers in a wide spectrum of industries such as gas turbine manufacturers to use less expensive and more available material in their production of combustors.Copyright © 2004 by ASME

Jörg Riccius - One of the best experts on this subject based on the ideXlab platform.

  • A first step into the blanching modelling of Liquid Rocket Engines: taking into account the roughness increase of the Chamber Wall
    AIAA Propulsion and Energy 2019 Forum, 2019
    Co-Authors: Jörg Riccius, Micha Böttcher
    Abstract:

    Whereas pure oxidation of a copper based liquid rocket combustion Chamber Wall results (due to the brown color of copper oxide) in a darkening of the hot-gas side of this Chamber Wall, blanching (on the contrary) leads to a lighter color. This is a result of a cyclic oxidation and reduction of the Chamber Wall material. The most important influence of blanching is the roughness increase of the Chamber Wall. The strong effect of this roughness increase is exemplarily considered for the main combustion Chamber of a 10 MPa Chamber pressure, 1 MN vacuum thrust reference engine. A thermally fully coupled CFD analysis of the hot-gas flow and thermal FE analysis of the heat conduction in the Chamber Wall and CFD analysis of the coolant flow is applied to a Chamber Wall model of this reference engine. By running this analysis for both: initial (small) roughness as well as blanching-caused (strongly increased) roughness, the severe thermal influence of blanching can be assessed. Finally, the blanching-caused decrease of the fatigue life of the Chamber Wall of the reference engine is shown

  • A superposition methodology for modeling the multi-directional flow through a non-orthotropic porous combustion Chamber Wall material
    2014
    Co-Authors: W. Bouajila, Jörg Riccius
    Abstract:

    As an attractive alternative to the well-established regenerative cooling technology, DLR has spent many years in developing an effusion cooling design that could be used for rocket engine combustion Chamber Wall cooling. A porous carbon fiber/carbon matric (C/C) composite material that shows a high specific strength and very low thermal expansion over a large temperature range has been tested as a possible substitute for the copper based alloys conventionally used as combustion Chamber Wall material for highly efficient large thrust rocket engines. Due to the complexity of the structure of the investigated carbon fiber / carbon matrix (C/C) composite material, a superposition methodology, presented in this paper, has been used to:  Determine the Forchheimer model parameters for the permeability of the C/C material from experimental measurements.  Model the multi-directional flow through the nonorthotropic porous thrust Chamber Wall material. A test bench that uses cylindrical probes of C/C composite material designed in DLR Lampoldshausen has been used to determine the permeability of the material. The predicted mass flow rates for a cylindrical test sample are compared to experimental measurements for wide ranges of pressures and pressure drops in order to demonstrate the accuracy of the optimized permeability parameters. The distribution of the coolant flow throughout a cross section of a subscale combustion Chamber Wall made from the C/C material and the profile of the flow rate of the coolant flowing out of the combustion Chamber surface are simulated performing cold flow CFD analyses.

  • STRUCTURAL ANALYSIS OF THE CYCLIC LOADING OF REGENERATIVELY COOLED COMBUSTION Chamber WallS USING 2D AND 3D FINITE ELEMENT MODELS
    2006
    Co-Authors: Jörg Riccius, Oskar Haidn, Evgeny Zametaev
    Abstract:

    A coupled thermal and structural 3d quasi stationary Finite Element (FEM) analysis of a typical rocket combustion Chamber Wall during a full cycle including pre cooling, hot run, post cooling and relaxation is presented. The results of this 3d analysis are compared with the results of 2d plane strain and 2d generalized plane strain analyses. Finally, a post-processing method is applied in order to estimate the combustion Chamber life time. This life time estimation method takes into account the standard Low Cycle Fatigue part as well as additional parts – accounting for the quasi static (or ratcheting) fatigue and the thermal degradation of the Chamber Wall material.

  • LRE Chamber Wall Optimization Using Plane Strain and Generalized Plane Strain Models
    42nd AIAA ASME SAE ASEE Joint Propulsion Conference & Exhibit, 2006
    Co-Authors: Jörg Riccius, Evgeny Zametaev, Oskar Haidn, Christian Gogu, Ecole Nationale
    Abstract:

    A method for the optimization of rocket combustion Chamber Walls with respect to the life time is presented. This method can be split into four main parts: P1) Determination of the thermal field within the combustion Chamber Wall and the cooling channel during the hot run phase by a steady state thermo-fluid mechanical analysis; P2) Analysis of the nonlinear deformation of the combustion Chamber Wall under cyclic thermal and mechanical loading using a 2d plane strain or a 2d generalized plane strain model; P3) Estimation of the life time of the combustion Chamber Wall by a post processing method and P4) Application of a mathematical optimization procedure (gradient free or Conjugate Gradient method). This strategy is used to analyse the thermal load induced deformation process and life time of a typical rocket combustion Chamber and to optimise selected geometry parameters of the combustion Chamber Wall.

  • Comparison of 2d and 3d Structural FE-Analyses of LRE Combustion Chamber Walls
    42nd AIAA ASME SAE ASEE Joint Propulsion Conference & Exhibit, 2006
    Co-Authors: Jörg Riccius, Evgeny Zametaev, Oskar Haidn, Gaelle De Boisvilliers
    Abstract:

    A coupled thermal and structural 3d quasi stationary Finite Element (FEM) analysis of a typical rocket combustion Chamber Wall during a full cycle including pre cooling, hot run, post cooling and relaxation is presented. The results of this 3d analysis are compared with the results of 2d plane strain and 2d generalized plane strain analyses. Finally, a post-processing method is applied in order to estimate the combustion Chamber life time. This life time estimation method takes into account the standard Low Cycle Fatigue part as well as additional parts – accounting for the quasi static (or ratcheting) fatigue and the thermal degradation of the Chamber Wall material.

A. Ghafourian - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Vortex Flow on Heat Transfer to Combustion Chamber Wall
    Journal of Engineering for Gas Turbines and Power, 2006
    Co-Authors: A. Ghafourian, M. H. Saidi, Saeed Jahangirian, Mehdi Abarham
    Abstract:

    A new experimental facility was designed, fabricated, and tested to model and study the effect of bidirectional swirl flow on the rate of heat transfer to combustion Chamber Walls. Reduction of this heat transfer can result in time and cost of design and fabrication methods of combustion Chambers. The experimental study was performed using propane and air with oxygen as fuel and oxidizer, respectively. For similar flow rates, in cases where bidirectional flow was present, Wall temperature reductions of up to 70% were observed. In cases where only some of the oxidizer was injected from the Chamber end to generate the bidirectional swirl flow, the lowest Wall temperature existed. This can be due to better mixing of fuel and oxidizer and absence of hot spots in the combustion core.

  • Effect of Vortex Flow on Heat Transfer to Combustion Chamber Wall
    Energy Conversion and Resources: Fuels and Combustion Technologies Energy Nuclear Engineering, 2004
    Co-Authors: Saeed Jahangirian, A. Ghafourian, Mehdi Abarham, M. H. Saidi
    Abstract:

    A new experimental facility was designed, fabricated and tested to model and study the effect of bidirectional swirl flow on the rate of heat transfer to combustion Chamber Walls in many applications. Heat transfer to combustion Chamber Walls is an unwanted phenomenon. Reduction of this heat transfer can result in time and cost saving methods in design and fabrication of combustion Chambers. The experimental study was performed by using propane and air with oxygen as fuel and oxidizer respectively. The location of injection ports and geometry of combustion Chamber are flexible and could be varied. Tests were performed with different mass flow rates of fuel and oxidizer. For the same flow rates and with the presence of bidirectional flow, a Wall temperature reduction of up to 50% was observed. In cases where only some of the oxidizer was injected from the Chamber end to generate the bidirectional swirl flow, highest efficiency and lowest Wall temperature existed. This can be due to better mixing of fuel and oxidizer and absence of hot spots in the combusting core. Further development of this technique enables combustion Chamber manufacturers in a wide spectrum of industries such as gas turbine manufacturers to use less expensive and more available material in their production of combustors.Copyright © 2004 by ASME

M. H. Saidi - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Vortex Flow on Heat Transfer to Combustion Chamber Wall
    Journal of Engineering for Gas Turbines and Power, 2006
    Co-Authors: A. Ghafourian, M. H. Saidi, Saeed Jahangirian, Mehdi Abarham
    Abstract:

    A new experimental facility was designed, fabricated, and tested to model and study the effect of bidirectional swirl flow on the rate of heat transfer to combustion Chamber Walls. Reduction of this heat transfer can result in time and cost of design and fabrication methods of combustion Chambers. The experimental study was performed using propane and air with oxygen as fuel and oxidizer, respectively. For similar flow rates, in cases where bidirectional flow was present, Wall temperature reductions of up to 70% were observed. In cases where only some of the oxidizer was injected from the Chamber end to generate the bidirectional swirl flow, the lowest Wall temperature existed. This can be due to better mixing of fuel and oxidizer and absence of hot spots in the combustion core.

  • Effect of Vortex Flow on Heat Transfer to Combustion Chamber Wall
    Energy Conversion and Resources: Fuels and Combustion Technologies Energy Nuclear Engineering, 2004
    Co-Authors: Saeed Jahangirian, A. Ghafourian, Mehdi Abarham, M. H. Saidi
    Abstract:

    A new experimental facility was designed, fabricated and tested to model and study the effect of bidirectional swirl flow on the rate of heat transfer to combustion Chamber Walls in many applications. Heat transfer to combustion Chamber Walls is an unwanted phenomenon. Reduction of this heat transfer can result in time and cost saving methods in design and fabrication of combustion Chambers. The experimental study was performed by using propane and air with oxygen as fuel and oxidizer respectively. The location of injection ports and geometry of combustion Chamber are flexible and could be varied. Tests were performed with different mass flow rates of fuel and oxidizer. For the same flow rates and with the presence of bidirectional flow, a Wall temperature reduction of up to 50% was observed. In cases where only some of the oxidizer was injected from the Chamber end to generate the bidirectional swirl flow, highest efficiency and lowest Wall temperature existed. This can be due to better mixing of fuel and oxidizer and absence of hot spots in the combusting core. Further development of this technique enables combustion Chamber manufacturers in a wide spectrum of industries such as gas turbine manufacturers to use less expensive and more available material in their production of combustors.Copyright © 2004 by ASME

Saeed Jahangirian - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Vortex Flow on Heat Transfer to Combustion Chamber Wall
    Journal of Engineering for Gas Turbines and Power, 2006
    Co-Authors: A. Ghafourian, M. H. Saidi, Saeed Jahangirian, Mehdi Abarham
    Abstract:

    A new experimental facility was designed, fabricated, and tested to model and study the effect of bidirectional swirl flow on the rate of heat transfer to combustion Chamber Walls. Reduction of this heat transfer can result in time and cost of design and fabrication methods of combustion Chambers. The experimental study was performed using propane and air with oxygen as fuel and oxidizer, respectively. For similar flow rates, in cases where bidirectional flow was present, Wall temperature reductions of up to 70% were observed. In cases where only some of the oxidizer was injected from the Chamber end to generate the bidirectional swirl flow, the lowest Wall temperature existed. This can be due to better mixing of fuel and oxidizer and absence of hot spots in the combustion core.

  • Effect of Vortex Flow on Heat Transfer to Combustion Chamber Wall
    Energy Conversion and Resources: Fuels and Combustion Technologies Energy Nuclear Engineering, 2004
    Co-Authors: Saeed Jahangirian, A. Ghafourian, Mehdi Abarham, M. H. Saidi
    Abstract:

    A new experimental facility was designed, fabricated and tested to model and study the effect of bidirectional swirl flow on the rate of heat transfer to combustion Chamber Walls in many applications. Heat transfer to combustion Chamber Walls is an unwanted phenomenon. Reduction of this heat transfer can result in time and cost saving methods in design and fabrication of combustion Chambers. The experimental study was performed by using propane and air with oxygen as fuel and oxidizer respectively. The location of injection ports and geometry of combustion Chamber are flexible and could be varied. Tests were performed with different mass flow rates of fuel and oxidizer. For the same flow rates and with the presence of bidirectional flow, a Wall temperature reduction of up to 50% was observed. In cases where only some of the oxidizer was injected from the Chamber end to generate the bidirectional swirl flow, highest efficiency and lowest Wall temperature existed. This can be due to better mixing of fuel and oxidizer and absence of hot spots in the combusting core. Further development of this technique enables combustion Chamber manufacturers in a wide spectrum of industries such as gas turbine manufacturers to use less expensive and more available material in their production of combustors.Copyright © 2004 by ASME