scholarly journals Numerical simulation of heat transfer during leaf spring industrial quenching process

2018 ◽  
Vol 19 (3) ◽  
pp. 304 ◽  
Author(s):  
Salma Slama ◽  
Mahmoud Bouhafs ◽  
Jamel Bessrour ◽  
Moez Ben Jaber ◽  
Hassan Mokdadi
Keyword(s):  
Heat Transfer ◽  
Numerical Model ◽  
Ambient Air ◽  
Space Time ◽  
Temperature Evolution ◽  
Leaf Spring ◽  
Parabolic Profile ◽  
Leaf Springs ◽  
Steel Aisi ◽  
The Heat Transfer Coefficient

This study is carried out in partnership with the company CAVEO, manufacturer of leaf springs for vehicles. It concerns the development of a numerical model intended to follow the space-time temperature evolution of a leaf during two processing operations: hot cambering and quenching. This leaf is of a parabolic profile, made of EN-51CrV4 steel (AISI-6150). After austenitization, it passes through a cambering operation to confer it the desired deflection and then a quenching operation. This quenching is carried out in an oil bath to achieve better mechanical properties. The prediction of the temperature during quenching involves determining the heat transfer coefficient between the leaf and the oil bath. This coefficient is determined by quenching, under the same conditions as the leaf, using a standard probe of the same steel. The numerical model is based on the resolution of the transient heat equation by considering the heat loss flows towards the heterogeneous environment (ambient air, press contact and quenching oil). The results obtained by this model give the space-time temperature evolution of the leaf from the exit of the heating furnace to the exit of the oil bath. The numerical results are compared to the experimental profiles obtained through thermographic images throughout cambering and quenching operations. These results are consistent with experimental results.

scholarly journals Thermo-mechanical and metallurgical model of leaf spring industrial quenching process

2021 ◽  
Author(s):  
Salma SLAMA ◽  
Moez BEN JABEUR ◽  
Khalil MANSOURI ◽  
Muhammad ZAIN-UL-ABDEIN ◽  
Jamel BESSROUR ◽  
...  
Keyword(s):  
Numerical Model ◽  
Constitutive Law ◽  
Leaf Spring ◽  
The Finite Element Method ◽  
Parabolic Profile ◽  
Quenching Process ◽  
Steel Aisi ◽  
Implicit Solver ◽  
Spatio Temporal ◽  
Set Up

Abstract This study is a numerical analysis of the industrial quenching process for leaf springs developed by the CAVEO company. The leaf chosen for this study is of a parabolic profile made of EN-51CrV4 steel (AISI 6150). The aim of this study is to set up a numerical model to predict thermal, metallurgical, and mechanical behavior of a leaf spring from exit of the heating furnace to exit of the quenching bath going through a cambering operation. This study would therefore allow the company to switch from a development scheme based on experiments using physical prototypes tested on the production line to a new scheme based on virtual prototypes using numerical simulation. The development of the numerical model using the finite element method is carried out using the ABAQUS/Implicit solver coupled with two user subroutines Phase and UMAT. The first one have been developed to compute microstructure evolution and the second one to define the constitutive law taking into account phase transformations. This model helps us to follow the spatio-temporal evolutions of temperature and microstructure in the leaf, as well as the variation of the leaf deflection during the process. The proposed numerical model is supported by an experimental protocol based on infrared thermographic images, Rockwell-C hardness measurements, metallographic observations, and deflection measurements. Indeed, the results of the proposed thermo-mechanical and metallurgical model are closed to experimental results.

Thermo-mechanical analysis of a FGM plate subjected to thermal shock – A new numerical approach considering real time temperature dependent material properties

2021 ◽  
Vol 63 (4) ◽  
pp. 341-349
Author(s):  
Mete Onur Kaman ◽  
Nevin Celik ◽  
Resul Das
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Thermal Shock ◽  
Temperature Variation ◽  
Material Properties ◽  
Ambient Air ◽  
Transient Temperature ◽  
Heated Plate ◽  
The Heat Transfer Coefficient

Abstract In present the study, sudden cooling, in other words thermal shock, is applied to a plate that is originally a functionally graded material (FGM). The flat plate is assumed to have an edge crack on it. Hence a numerical couple-field analysis is performed on the plate. The FGM is a combination of Ni and Al2O3. The thermal and mechanical properties of the FGM are assumed to depend on temperature variation. The mixing percentages of the Ni and Al2O3 throughout the plate are considered to vary (i) linearly, (ii) quadratically and (iii) in half-order. In order to solve the problem, a new subroutine depending on temperature is written using APDL (ANSYS Parametric Design Language) codes. Three values of the heat transfer coefficient are applied to the initially heated plate. As a result, the transient temperature variation and stress intensity factor are presented to show the thermo-mechanical relation of the plate. The material properties changing with temperature results in more reliable temperature values. Increasing the heat transfer coefficient results in better cooling and in a lesser amount of time to reach ambient air temperature.

Localized Heat Transfer in Buoyancy Driven Convection in Open Cavities

2006 ◽  
Vol 129 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Wilson Terrell ◽  
Ty A. Newell
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Average Nusselt Number ◽  
Convection Heat Transfer ◽  
Ambient Air ◽  
Nusselt Numbers ◽  
Transient Nature ◽  
Inclination Angles ◽  
Buoyancy Driven Convection ◽  
The Heat Transfer Coefficient

Background. An experimental study of buoyancy driven convection heat transfer in an open cavity was conducted. Method of Approach. Test cavities were constructed with calorimeter plates bonded to Styrofoam insulation. The inside of the cavities was heated and then exposed to ambient air for approximately thirty minutes. Different size cavities were examined at inclination angles of 0, 45, and 90deg. The heat transfer coefficient was determined from an energy balance on each calorimeter plate. The cavity’s plate temperatures varied spatially due to the transient nature of the tests. A parameter describing the nonisothermal cavity wall temperature variation was defined in order to compare with isothermal cavity heat transfer results. Results. Results showed that the cavity Nusselt number, based on a cavity averaged temperature, was insensitive to the transient development of nonisothermal conditions within the cavity. Comparison of cavity-average Nusselt number for the current study, where the Rayleigh number ranged from 5×106 to 2×108, to data from the literature showed good agreement. Cavity-average Nusselt number relations for inclination angles of 0, 45, and 90deg in the form of NuH,cav=CRa1∕3 resulted in coefficients of 0.091, 0.105, 0.093, respectively. The 45deg inclination angle orientation yielded the largest Nusselt numbers, which was similar to previous literature results. Trends in the local plate Nusselt numbers were examined and found similar to data from the literature.

scholarly journals Numerical and CFD Design of Heat Exchanger Used to Biomass Combustion

2020 ◽  
Vol 328 ◽  
pp. 02005
Author(s):  
Marian Pafcuga ◽  
Andrej Kapjor ◽  
David Hecko ◽  
Martin Vantuch
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Numerical Model ◽  
Flue Gas ◽  
Biomass Combustion ◽  
Cfd Model ◽  
Heat Transfer Medium ◽  
The Heat Transfer Coefficient ◽  
Tube Space

The article describes the design of a heat exchanger used for biomass combustion. The design takes into account simple maintenance of the exchanger, low input costs of construction and the highest possible efficiency. In the design is used the tubular type of heat exchanger. The construction consists of a tubular part - flue gas part, inter-tube space - heat transfer medium space. The output of the numerical model, CFD model is the heat transfer coefficient, heat exchanger power and final comparison of CFD and numerical model outputs.

scholarly journals Numerical analysis of wagon leaf spring using Ansys 14.5

2021 ◽  
Vol 27 (4) ◽  
pp. 119-123
Author(s):  
Mladen Krstić ◽  
Branislav Milenković ◽  
Đorđe Jovanović
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Static Analysis ◽  
Software Package ◽  
Suspension System ◽  
Leaf Spring ◽  
Cad Model ◽  
Commercial Vehicles ◽  
Ansys Software ◽  
Leaf Springs

Leaf springs are widely used for the suspension system in trains and commercial vehicles to absorb vibrations and shocks. This paper deals with the methodology of analysis of the leaf springs of the freight railway wagons by using software package Ansys 14.5. The methodology is applied in a concrete example of leaf spring for axle load of 225 kN. The procedure of forming the CAD model of the leaf spring using AutoCad and Autodesk Inventor is exposed, as well as the development of numerical model in Ansys software package. The results of the static analysis of given leaf spring are presented and commented.

Evaporation of lignin-lean black liquor

TAPPI Journal ◽  
2015 ◽  
Vol 14 (7) ◽  
pp. 441-450
Author(s):  
HENRIK WALLMO, ◽  
ULF ANDERSSON ◽  
MATHIAS GOURDON ◽  
MARTIN WIMBY
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Black Liquor ◽  
Salt Content ◽  
Solubility Limit ◽  
Lignin Removal ◽  
Kraft Black Liquor ◽  
Black Liquors ◽  
The Heat Transfer Coefficient

Many of the pulp mill biorefinery concepts recently presented include removal of lignin from black liquor. In this work, the aim was to study how the change in liquor chemistry affected the evaporation of kraft black liquor when lignin was removed using the LignoBoost process. Lignin was removed from a softwood kraft black liquor and four different black liquors were studied: one reference black liquor (with no lignin extracted); two ligninlean black liquors with a lignin removal rate of 5.5% and 21%, respectively; and one liquor with maximum lignin removal of 60%. Evaporation tests were carried out at the research evaporator in Chalmers University of Technology. Studied parameters were liquor viscosity, boiling point rise, heat transfer coefficient, scaling propensity, changes in liquor chemical composition, and tube incrustation. It was found that the solubility limit for incrustation changed towards lower dry solids for the lignin-lean black liquors due to an increased salt content. The scaling obtained on the tubes was easily cleaned with thin liquor at 105°C. It was also shown that the liquor viscosity decreased exponentially with increased lignin outtake and hence, the heat transfer coefficient increased with increased lignin outtake. Long term tests, operated about 6 percentage dry solids units above the solubility limit for incrustation for all liquors, showed that the heat transfer coefficient increased from 650 W/m2K for the reference liquor to 1500 W/m2K for the liquor with highest lignin separation degree, 60%.

scholarly journals A numerical model and validation of phase change material integrated thermoelectric radiant cooling panel

2019 ◽  
Vol 111 ◽  
pp. 01001
Author(s):  
Hansol Lim ◽  
Hye-Jin Cho ◽  
Seong-Yong Cheon ◽  
Soo-Jin Lee ◽  
Jae-Weon Jeong
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Numerical Model ◽  
Surface Temperature ◽  
Phase Change ◽  
Transfer Coefficient ◽  
Phase Change Material ◽  
Overall Heat Transfer Coefficient ◽  
Radiant Cooling ◽  
Change Material

A phase change material based radiant cooling panel with thermoelectric module (PCM-TERCP) is proposed in this study. It consists of two aluminium panels, and phase change materials (PCMs) sandwiched between the two panels. Thermoelectric modules (TEMs) are attached to one of the aluminium panels, and heat sinks are attached to the top side of TEMs. PCM-TERCP is a thermal energy storage concept equipment, in which TEMs freeze the PCM during the night whose melting temperature is 16○C. Therefore, the radiant cooling panel can maintain a surface temperature of 16◦C without the operation of TEM during the day. Furthermore, it is necessary to design the PCM-TERCP in a way that it can maintain the panel surface temperature during the targeted operating time. Therefore, the numerical model was developed using finite difference method to evaluate the thermal behaviour of PCM-TERCP. Experiments were also conducted to validate the performance of the developed model. Using the developed model, the possible operation time was investigated to determine the overall heat transfer coefficient required between radiant cooling panel and TEM. Consequently, the results showed that a overall heat transfer coefficient of 394 W/m2K is required to maintain the surface temperature between 16○C to 18○C for a 3 hours operation.

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