Modeling of Temperature Distributions in the Workpiece During Abrasive Waterjet Machining

1993 ◽  
Vol 115 (2) ◽  
pp. 446-452 ◽  
Author(s):  
M. M. Ohadi ◽  
K. L. Cheng
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Abrasive Waterjet ◽  
Block Type ◽  
Analysis Tool ◽  
Operational Parameters ◽  
Conduction Model ◽  
Steady State Condition ◽  
Temperature Distributions ◽  
Awj Cutting

Modeling of temperature distributions in a block-type workpiece during cutting with an abrasive waterjet (AWJ) was the subject of an analytical/experimental investigation in the present study. The experiments included measurement of detailed time-temperature distributions in the workpiece for selected AWJ/workpiece operational parameters. Mathematical modeling of the problem made use of a two-part process. In the first part, the measured experimental data were fed into an inverse heat conduction algorithm, which determined the corresponding heat flux in the workpiece. In the second part, this heat flux was fed into a two-dimensional transient heat conduction model that calculated the corresponding temperature distributions in the workpiece. It is demonstrated that the proposed model can serve as a useful thermal analysis tool for AWJ cutting processes so long as a quasi-steady-state condition can be established in the workpiece.

scholarly journals Non-Fourier Heat Conduction of a Functionally Graded Cylinder Containing a Cylindrical Crack

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Jiawei Fu ◽  
Keqiang Hu ◽  
Linfang Qian ◽  
Zengtao Chen
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Intensity Factor ◽  
Functionally Graded ◽  
Conduction Model ◽  
Heat Conduction Model ◽  
Flux Intensity ◽  
Cylindrical Crack ◽  
Heat Flux Intensity ◽  
Fourier Heat Conduction

The present work investigates the problem of a cylindrical crack in a functionally graded cylinder under thermal impact by using the non-Fourier heat conduction model. The theoretical derivation is performed by methods of Fourier integral transform, Laplace transform, and Cauchy singular integral equation. The concept of heat flux intensity factor is introduced to investigate the heat concentration degree around the crack tip quantitatively. The temperature field and the heat flux intensity factor in the time domain are obtained by transforming the corresponding quantities from the Laplace domain numerically. The effects of heat conduction model, functionally graded parameter, and thermal resistance of crack on the temperature distribution and heat flux intensity factor are studied. This work is beneficial for the thermal design of functionally graded cylinder containing a cylindrical crack.

Development and Implementation of a 3D Heat Conduction Model for (Very) High Temperature Reactors Into the Reactor Dynamics Code DYN3D

2012 ◽  
Author(s):  
Silvio Baier ◽  
Ulrich Rohde ◽  
Soeren Kliem ◽  
Emil Fridman
Keyword(s):  
Heat Conduction ◽  
High Temperature ◽  
Block Type ◽  
Conduction Model ◽  
Heat Conduction Model ◽  
Reactor Dynamics ◽  
3D Effects ◽  
High Temperature Reactors ◽  
Short Time ◽  
Very High

The reactor dynamics code DYN3D was extended to treat phenomena in Block-type High Temperature Reactors (HTR). Therefor, a new heat conduction model was implemented into the code to tackle 3D effects of heat conduction and heat transfer. The first part of the paper describes the details of the heat conduction model. In the second part results of coupled neutron-kinetics/thermal-hydraulics calculations of steady state and short-time transients in block-type HTRs are discussed.

Gas Turbine Combustor Liner Wall Heat Load Characterization for Different Gaseous Fuels

2019 ◽  
Author(s):  
Kishore Ranganath Ramakrishnan ◽  
Shoaib Ahmed ◽  
Benjamin Wahls ◽  
Prashant Singh ◽  
Maria A. Aleman ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Load ◽  
Recirculation Zone ◽  
Flame Temperature ◽  
Conduction Model ◽  
Steady State Condition ◽  
Gaseous Fuels ◽  
Peak Heat Flux ◽  
Combustor Liner

Abstract The knowledge of detailed distribution of heat load on swirl stabilized combustor liner wall is imperative in the development of liner-specific cooling arrangements, aimed towards maintaining uniform liner wall temperatures for reduced thermal stress levels. Heat transfer and fluid flow experiments have been conducted on a swirl stabilized lean premixed combustor to understand the behavior of Methane-, Propane-, and Butane-based flames. These fuels were compared at different equivalence ratios for a matching adiabatic flame temperature of Methane at 0.65 equivalence ratio. Above experiments were carried out a fixed Reynolds number (based on the combustor diameter) of 12000, where the pre-heated air temperature was approximately 373K. Combustor liner in this setup was made from 4 mm thick quartz tube. An infrared camera was used to record the inner and outer temperatures of liner wall, and two-dimensional heat conduction model was used to find the wall heat flux at a quasi-steady state condition. Flow field in the combustor was measured through Particle Image Velocimetry. The variation of peak heat flux on the liner wall, position of peak heat flux and heat transfer, and position of impingement of flame on the liner have been presented in this study. For all three gaseous fuels studied, the major swirl stabilized flame features such as corner recirculation zone, central recirculation zone and shear layers have been observed to be similar. Liner wall and exhaust temperature for Butane was highest among the fuel tested in this study which was expected as the heat released from combustion of Butane is higher than that of Methane and Propane.

Developing an Inverse Heat Conduction Analysis Tool for Real Time Heat Flux Estimation in Directional Flame Thermometer Application

2014 ◽  
Author(s):  
Hamidreza Najafi ◽  
Keith Woodbury
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Real Time ◽  
Data Gathering ◽  
Time Algorithm ◽  
Industrial Applications ◽  
Furnace Operation ◽  
Temperature Data ◽  
Analysis Tool ◽  
Inverse Heat Conduction

Accurate measurement of heat flux and temperature can significantly affect the energy usage in several industrial applications, including furnace operation, metal processing, fire safety tests and more. Directional Flame Thermometers, or DFTs, offer the ability to use both temperature and heat flux measurements for furnace control. Currently, analysis of dynamic temperature data from the DFTs to compute heat flux information must be performed off-line at the conclusion of data-gathering by using software tools such as IHCP1D. Availability of a near real-time algorithm for accurate reduction of the data will allow for continual monitoring of the furnace during operation. This will result in better control over the process and significant savings in energy and cost. In this paper, a filter form of the inverse heat conduction algorithm is developed for utilization in DFTs. The algorithm is based on linearized solutions of the direct heat equation, and non-linear effects introduced by temperature dependent thermal properties are accounted for by interpolating of the resulting filter coefficients. The developed method is tested through several numerical experiments and also ANSYS model. A graphical user interface is developed in LabVIEW to provide a friendly interface for the end user. The temperature data measured by thermocouples on the DFT are transmitted to the computer through data acquisition card and the developed tool in LabView display the heat flux in a near real time fashion.

scholarly journals Analysis of temperature distribution in a pipe with inner mineral deposit

2014 ◽  
Vol 35 (2) ◽  
pp. 37-49
Author(s):  
Magda Joachimiak ◽  
Michał Ciałkowski ◽  
Jarosław Bartoszewicz
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Mineral Deposit ◽  
Mineral Deposits ◽  
Heat Conduction Coefficient ◽  
Temperature Distributions

Abstract The paper presents the results of calculations related to determination of temperature distributions in a steel pipe of a heat exchanger taking into account inner mineral deposits. Calculations have been carried out for silicate-based scale being characterized by a low heat transfer coefficient. Deposits of the lowest values of heat conduction coefficient are particularly impactful on the strength of thermally loaded elements. In the analysis the location of the thermocouple and the imperfection of its installation were taken into account. The paper presents the influence of determination accuracy of the heat flux on the pipe external wall on temperature distribution. The influence of the heat flux disturbance value on the thickness of deposit has also been analyzed.

On the Analysis of Short-Pulse Laser Heating of Metals Using the Dual Phase Lag Heat Conduction Model

2009 ◽  
Vol 131 (11) ◽  
Author(s):  
K. Ramadan ◽  
W. R. Tyfour ◽  
M. A. Al-Nimr
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Laser Heating ◽  
Flux Distribution ◽  
Heat Losses ◽  
Phase Lag ◽  
Dual Phase ◽  
Heat Flux Distribution ◽  
Conduction Model ◽  
Initial Heat

Transient heat conduction in a thin metal film exposed to short-pulse laser heating is studied using the dual phase lag heat conduction model. The initial heat flux distribution in the film, resulting from the temporal distribution function of the laser pulse, together with the zero temperature gradients at the boundaries normally used in literature with the presumption that they are equivalent to negligible boundary heat losses is analyzed in detail in this paper. The analysis presented here shows that using zero temperature gradients at the boundaries within the framework of the dual phase lag heat conduction model does not guarantee negligible boundary heat losses unless the initial heat flux distribution is negligibly small. Depending on the value of the initial heat flux distribution, the presumed negligible heat losses from the boundaries can be even way larger than the heat flux at any location within the film during the picosecond laser heating process. Predictions of the reflectivity change of thin gold films due to a laser short heat pulse using the dual phase lag model with constant phase lags are found to deviate considerably from the experimental data. The dual phase lag model is found to overestimate the transient temperature in the thermalization stage of the laser heating process of metal films, although it is still superior to the parabolic and hyperbolic one-step models.

Thermal Responses of a Thin Plate under Periodic Heat Flux Oscillation

2014 ◽  
Vol 578-579 ◽  
pp. 902-906
Author(s):  
Qiang Nian Li
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Thin Plate ◽  
Separation Of Variables ◽  
Temperature Response ◽  
Conservation Equation ◽  
Conduction Model ◽  
Thermal Behaviors ◽  
Heat Flux Vector ◽  
Periodic Heat

Thermal behaviors of a thin plate under a periodic surface thermal disturbance are investigated. The temperature and the displacement responses are predicted using the parabolic heat conduction model. The solution of temperature response is obtained by separation of variables. Firstly, an analytic expression of heat flux filed within the plate is obtained by using the parabolic heat conduction equation which is described by heat flux vector, then, based on the conservation equation of energy, the temperature response is given. The displacement response of the plate is solved analytically using the Nowachi’s and the Navier’s approachs. The thermal behaviors of a plate with various relatively parameters is calculated numerically and the results shown graphically.

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