Thermomechanical Design of a Heat Exchanger for a Recuperative Aeroengine

2006 ◽  
Vol 128 (4) ◽  
pp. 736-744 ◽  
Author(s):  
Harald Schoenenborn ◽  
Ernst Ebert ◽  
Burkhard Simon ◽  
Paul Storm
Keyword(s):  
Thermal Analysis ◽  
Heat Exchanger ◽  
Boundary Conditions ◽  
Stress Analysis ◽  
Element Model ◽  
Automatic Generation ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Engine Operation ◽  
Aero Engines

Within the framework programs of the EU for Efficient and Environmentally Friendly Aero-Engines (EEFEA) MTU has developed a highly efficient cross-counter flow heat exchanger for the application in intercooled recuperated aeroengines. This very compact recuperator is based on the profile tube matrix arrangement invented by MTU and one of its outstanding features is the high resistance to thermal gradients. In this paper the combined thermomechanical design of the recuperator is presented. State-of-the-art calculation procedures for heat transfer and stress analysis are combined in order to perform a reliable life prediction of the recuperator. The thermal analysis is based upon a 3D parametric finite element model generation. A program has been generated, which allows the automatic generation of both the material mesh and the boundary conditions. Assumptions concerning the boundary conditions are presented as well as steady state and transient temperature results. The stress analysis is performed with a FEM code using essentially the same computational grid as the thermal analysis. With the static temperature fields the static loading of the profile tubes is determined. From transient thermal calculations successive 3D temperature fields are obtained which enable the determination of creep life and LCF life of the part. Finally, vibration analysis is performed in order to estimate the vibration stress of the profile tubes during engine operation. Together with the static stress a Goodman diagram can be constructed. The combined analysis shows the high life potential of the recuperator, which is important for economic operation of a recuperative aero-engine.

Thermomechanical Design of a Heat Exchanger for a Recuperative Aero Engine

2004 ◽  
Author(s):  
Harald Scho¨nenborn ◽  
Ernst Ebert ◽  
Burkhard Simon ◽  
Paul Storm
Keyword(s):  
Thermal Analysis ◽  
Heat Exchanger ◽  
Boundary Conditions ◽  
Stress Analysis ◽  
Automatic Generation ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Engine Operation ◽  
Aero Engine ◽  
Aero Engines

Within the framework programs of the EU for Efficient and Environmentally Friendly Aero-Engines (EEFEA) MTU has developed a highly efficient cross-counter flow heat exchanger for the application in intercooled recuperated aero-engines. This very compact recuperator is based on the profile tube matrix arrangement invented by MTU and one of its outstanding features is the high resistance to thermal gradients. In this paper the combined thermomechanical design of the recuperator is presented. State-of-the-art calculation procedures for heat transfer and stress analysis are combined in order to perform a reliable life prediction of the recuperator. The thermal analysis is based upon a 3D parametric finite element model generation. A program has been generated, which allows the automatic generation of both the material mesh and the boundary conditions. Assumptions concerning the boundary conditions are presented as well as steady state and transient temperature results. The stress analysis is performed with a FEM code using essentially the same computational grid as the thermal analysis. With the static temperature fields the static loading of the profile tubes is determined. From transient thermal calculations successive 3D temperature fields are obtained which enable the determination of creep life and LCF life of the part. Finally, vibration analysis is performed in order to estimate the vibration stress of the profile tubes during engine operation. Together with the static stress a Goodman diagram can be constructed. The combined analysis shows the high life potential of the recuperator, which is important for economic operation of a recuperative aero-engine.

Study on Key Factors in Piston Transient Temperature Field

2013 ◽  
Vol 779-780 ◽  
pp. 958-964
Author(s):  
You Liu ◽  
Jing Jing Liu ◽  
Xiao Chen
Keyword(s):  
Temperature Field ◽  
Boundary Conditions ◽  
Theoretical Foundation ◽  
Element Model ◽  
Test Point ◽  
Transient Temperature ◽  
Feature Points ◽  
Key Factors ◽  
Transient Temperature Field ◽  
Transient Numerical Simulation

By means of ANSYS, piston finite element model is constructed to attain transient numerical simulation and explore the characteristics of surface temperature. On the basis of experimental design, the correlation is analyzed between major boundary conditions and temperature of feature points, thus revealing the corresponding correlation of quantity. Transient calculation method is proved to be scientific and paves way to defining boundary conditions. And furthermore there forms a theoretical foundation for positioning test point in piston temperature field.

Discharge of Thermal Storage Tanks via Immersed Baffled Heat Exchangers: Numerical Model of Flow and Temperature Fields

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Yan Su ◽  
Jane H. Davidson
Keyword(s):  
Heat Exchanger ◽  
Discharge Rate ◽  
Thermal Storage ◽  
Flow Speed ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Stored Energy ◽  
Tube Heat Exchanger ◽  
Temperature And Velocity Fields ◽  
Cylindrical Baffle

A model of a thermal storage tank in which stored energy is extracted via an immersed heat exchanger is presented and used to predict transient temperature and velocity fields in tanks with and without baffles. The heat exchanger is modeled as a porous medium within the storage fluid. A simple cylindrical baffle that creates an annular space in which a coiled tube heat exchanger is positioned provides a modest increase in the rate of energy extraction compared to a tank with no baffle. The improved discharge rate is attributed to an increase in the flow speed across the heat exchanger. A baffle with greater hydraulic resistance slows the flow and reduces performance.

Transient Thermo-Mechanical Stress Analysis of Hot Surface Probe Using Sequentially Coupled CFD-FEA Approach

2021 ◽  
Author(s):  
Sang-Guk Kang ◽  
Je Ir Ryu ◽  
Austen H. Motily ◽  
Prapassorn Numkiatsakul ◽  
Tonghun Lee ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Stress Analysis ◽  
Mechanical Stress ◽  
Failure Modes ◽  
Temperature History ◽  
Transient Temperature ◽  
Reacting Flow ◽  
Element Mesh ◽  
Surface Probe ◽  
Hot Surface

Abstract Energy addition using a hot surface probe is required for reliable ignition of aircraft compression ignition engines running on fuel variations and at altitude conditions. Thus, durability of the hot surface probe is crucial for application in these engines. Thermo-mechanical stress is one of the key parameters that determine durability, which requires an accurate prediction of the transient temperature field based on well-defined boundary conditions representing the dynamic and complex fluid flow inside engines. To meet this requirement, the present study focuses on transient thermo-mechanical stress analysis using a sequentially coupled CFD-FEA approach to understand transient thermo-mechanical responses of the hot surface probe. A 3D transient reacting flow simulation was conducted first using CONVERGE software, the results of which were exported to map thermal and pressure boundary conditions onto a structural finite element mesh. Transient thermo-mechanical stress analysis was performed sequentially using ABAQUS software utilizing the mapped boundary conditions. The results such as transient temperature history, resultant thermo-mechanical stress, displacement, potential failure modes, etc. were critically reviewed, which can provide helpful information for further design improvement.

Discharge of Thermal Storage Tanks via Immersed Baffled Heat Exchangers: Numerical Model of Flow and Temperature Fields

2007 ◽  
Author(s):  
Yan Su ◽  
Jane H. Davidson
Keyword(s):  
Heat Exchanger ◽  
Discharge Rate ◽  
Thermal Storage ◽  
Flow Speed ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Stored Energy ◽  
Tube Heat Exchanger ◽  
Temperature And Velocity Fields ◽  
Cylindrical Baffle

A model of a thermal storage tank in which stored energy is extracted via an immersed heat exchanger is presented and used to predict transient temperature and velocity fields in tanks with and without baffles. The heat exchanger is modeled as a porous medium within the storage fluid. A simple cylindrical baffle that creates an annular space in which a coiled tube heat exchanger is positioned provides a modest increase in the rate of energy extraction compared to a tank with no baffle. The improved discharge rate is attributed to an increase in the flow speed across the heat exchanger. A baffle with greater hydraulic resistance slows the flow and reduces performance.

Prediction of the Thermal Stability of Wheel Under Frequent Braking for Urban Rail Vehicle

2010 ◽  
Author(s):  
Zhizhuang Yu ◽  
Yong Wang ◽  
Jianyong Zuo ◽  
Bin Han ◽  
Leilei Gu
Keyword(s):  
Thermal Stability ◽  
Three Dimensional ◽  
Element Model ◽  
Urban Rail Transit ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Brake Shoe ◽  
Urban Rail ◽  
Electric Braking ◽  
Thermal Stability Of

A train is braked to stop when it reaches every station in an urban rail transit network. The combination of electro-pneumatic braking is currently adopted for many trains in China. The electric braking is manipulated prior to pneumatic braking. In the case of electric braking failure, the pneumatic braking device will then be used to perform ultimate protection. A typical pneumatic braking device includes a wheel and brake shoe. The work status of the wheel will certainly affect the running of train in frequent braking. In this paper, the authors established a three-dimensional finite element model (FEM) of wheel to simulate the three-dimensional transient temperature fields of the wheel at different running velocities and braking deceleration conditions. In addition, we analyzed the thermal stability of the wheel. Finally, we calculated the safety-related running velocity and braking deceleration. The results of the calculation are aimed to provide useful guidance for the urban rail operation in Chinese major cities. We recommend that the urban train speed should be lower than 60km/h when only the pneumatic braking device is used for braking.

scholarly journals Numerical Simulation on the Transient Temperature Field of Anode Rodding in Aluminium Reduction Cells

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1026
Author(s):  
Tuofu Li ◽  
Wenju Tao ◽  
Zhaowen Wang ◽  
Xiaozhen Liu ◽  
Jianfeng Hou
Keyword(s):  
Temperature Field ◽  
Cast Iron ◽  
Cooling Rate ◽  
Element Model ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Solidification Mode ◽  
Shrinkage Cavities ◽  
Transient Thermal ◽  
Bottom To Top

The temperature field of the anode rodding process is the root of most of problems related to the anode. A 3D transient thermal finite element model was developed, based on ANSYS in this paper. The temperature field of the rodding process was investigated using this model. The results were presented and analyzed in detail, including the transient temperature fields of different components in the anode, the characteristics of the cast iron solidification, and the cooling rate distribution. The conclusions were as follows. When the stub hole was filled up at 10 s, 30% by volume of cast iron was below the liquidus temperature. At 70 s, the cast iron solidified completely. The cast iron close to the stub solidified prior to that close to the carbon. The solidification mode was intermediate-freezing. The solidifying sequence was vertically from bottom to top, indicating that shrinkage cavities were less likely to occur. The temperature of the stub was higher than the carbon, and portion at high temperature was concentrated around the stub hole. The cooling rate during solidification was 4.3 °C s−1 to 43.7 °C s−1, and the gradient on the radial direction was relatively obvious.

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