Thermal-Structural Analysis for the Optimization of a Low Beam Projector Headlight Design

2015 ◽  
Vol 656-657 ◽  
pp. 747-752
Author(s):  
Jiing Hung You ◽  
Tamara Trejos ◽  
Huann Ming Chou ◽  
Song Hao Wang
Keyword(s):  
Heat Transfer ◽  
Thermal Expansion ◽  
Structure Design ◽  
Heat Transfer Analysis ◽  
Normal Operation ◽  
Complex Geometries ◽  
Switching Mechanism ◽  
Engineering Software ◽  
Modern Engineering ◽  
Structural Stresses

This paper is to demonstrate the application of modern Engineering Software to improve and advance the mechanical desig processes of a low beam projector headlight. Nowadays, advanced finite element tools are able to run and coupled different physics modules to analyze complex geometries and their material combinations. The particular issue in this study is the light switching mechanism in a headlight structure design. During lighting, the jam of the low beam projector solenoid actuated pivot due to thermal expansions has been distressing the normal operation of the overall headlight structure. A comparison between the original and a new convection enhanced head lamp design is therefore scrutinized. For both cases, heat transfer analysis, where it was included natural convection, conduction, and radiation with a concentrated heat source are proposed in order to obtain the temperature distribution fields at the light switching mechanism. The results were used to run future structural stresses analyses where the average thermal expansion of the crankshaft mechanism was determined.

Numerical Simulation of Subcooled Flow Boiling Heat Transfer in Helical Tubes

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Jong Chull Jo ◽  
Woong Sik Kim ◽  
Chang-Yong Choi ◽  
Yong Kab Lee
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Steam Generator ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Heat Transfer Analysis ◽  
Normal Operation ◽  
Phase Flow ◽  
Two Phase ◽  
Side Flow

This paper addresses the numerical simulation of two-phase flow heat transfer in the helically coiled tubes of an integral type pressurized water reactor steam generator under normal operation using a computational fluid dynamics code. The shell-side flow field where a single-phase fluid flows in the downward direction is also calculated in conjunction with the tube-side two-phase flow characteristics. For the calculation of tube-side two-phase flow, the inhomogeneous two-fluid model is used. Both the Rensselaer Polytechnic Institute wall boiling model and the bulk boiling model are implemented for the numerical simulations of boiling-induced two-phase flow in a vertical straight pipe and channel, and the computed results are compared with the available measured data. The conjugate heat transfer analysis method is employed to calculate the conduction in the tube wall with finite thickness and the convections in the internal and external fluids simultaneously so as to match the fluid-wall-fluid interface conditions properly. Both the internal and external turbulent flows are simulated using the standard k-ε model. From the results of the present numerical simulation, it is shown that the bulk boiling model can be applied to the simulation of two-phase flow in the helically coiled steam generator tubes. In addition, the present simulation method is considered to be physically plausible in the light of discussions on the computed results.

Numerical Simulation of Subcooled Flow Boiling Heat Transfer in Helical Tubes

2006 ◽  
Author(s):  
Jong Chull Jo ◽  
Woong Sik Kim ◽  
Chang-Yong Choi ◽  
Yong Kab Lee
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Steam Generator ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Heat Transfer Analysis ◽  
Normal Operation ◽  
Phase Flow ◽  
Two Phase ◽  
Pressurized Water

This paper addresses the numerical simulation of two phase flow heat transfer in the helically coiled tubes of an integral type pressurized water reactor steam generator under normal operation using a CFD code. The single phase flow which flow downward direction in the shell side is also calculated together. For the calculation of tube side two-phase flow the inhomogeneous two-fluid model is used. Both the RPI (Rensselaer Polytechnic Institute) wall boiling model and the bulk boiling model are implemented for the numerical simulation and the computed results are compared with the available measured data. The conjugate heat transfer analysis method is employed to calculate the conduction in the tube wall with finite thickness and the convections in the internal and external fluids simultaneously so as to match the fluid-wall-fluid interface conditions properly. Both the internal and external turbulent flows are simulated using the standard k-ε model From the results of present numerical simulation, it is shown that the bulk boiling model can be applied to the simulation of two-phase flow in the helically coiled steam generator tubes. The results also show that the present simulation method is considered to be physically plausible when the computed results are compared with available previous experimental and numerical studies.

A Heat Transfer Analysis for Passively Cooled “Trumpet” Secondary Concentrators

1987 ◽  
Vol 109 (4) ◽  
pp. 289-297 ◽  
Author(s):  
D. Suresh ◽  
J. O’Gallagher ◽  
R. Winston
Keyword(s):  
Heat Transfer ◽  
Thermal Load ◽  
Flux Distribution ◽  
The Body ◽  
Heat Transfer Analysis ◽  
Normal Operation ◽  
Transfer Model ◽  
Simulation Experiments ◽  
Ray Trace ◽  
Solar Thermal Applications

Some practical questions associated with the use of hyperboloidal “trumpet” shaped terminal concentrators for use in solar thermal applications are addressed. Computer ray-trace calculations show that the flux distribution is strongly peaked over a small neck area at the exit of the trumpet, which will be subjected to a substantial thermal load. A quasi-transient heat transfer model has been developed to analyze the thermal behavior of passively cooled trumpets. The thermal analysis shows that simple techniques exist such that one can design passive secondary trumpets which will remain below safe temperature limits under normal operation for many applications. The wall thickness and its variation along the body of the bell-shaped shell from the exit are found to play an important role in controlling the temperature at all flux levels. As a check on the validity of the model, a set of electrical simulation experiments was conducted and excellent agreement was found.

Heat Transfer Analysis for the Structural Integrity of EO Reactor

2007 ◽  
Author(s):  
Sung Won Park ◽  
Kwanwoo Nam ◽  
Young Soon Lim ◽  
Jung Yean Park ◽  
Choong Dong Lee
Keyword(s):  
Heat Transfer ◽  
Structural Integrity ◽  
Tube Bundle ◽  
Thermal Characteristics ◽  
Local Heat Transfer ◽  
Heat Transfer Analysis ◽  
Normal Operation ◽  
Two Dimensional ◽  
Operation Condition ◽  
Porous Media Model

Thermal characteristics of an EO (Ethylene Oxide) reactor are analyzed to investigate its structural integrity against thermal loads. A two-dimensional axisymmetric simulation model of the whole reactor structure is developed. A porous media model for the long tube bundle packed with catalyst and a flow resistance model for the thin impingement baffle is proposed to simplify the reactor. Simultaneous simulation of fluid and solid zone for a part with many holes is applied to analyze heat transfer of tubesheet which is connected with the tube bundle and the outer shell. The EOC (End of Catalyst Cycle) condition is used for the normal operation condition because general temperature of the EOC condition is the highest during operation cycle. Transient heat transfer analysis is also conducted to simulate the abnormal ignition in the reactor. Two kinds of ignitions are investigated and thermal diffusion in the reactor during the expected shutting down time is simulated as well. Three-dimensional local heat transfer analysis based on the two-dimensional whole analysis is conducted for the local stress evaluation of the product nozzle elbow and the impingement baffle. Results of the heat transfer analysis have been utilized as a thermal boundary condition for the further structural analysis.

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