scholarly journals AN INVERSE OPTIMIZATION PROBLEM OF HEAT TRANSFER IN THE MACHINING PROCESS – A REVIEW

2021 ◽  
Vol 24 (1) ◽  
pp. 10-21
Author(s):  
Marin Gostimirovic ◽  
◽  
Milenko Sekulic ◽  
Dragan Rodic ◽  
◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Optimization Problem ◽  
Inverse Optimization ◽  
Machining Process ◽  
Measured Temperature ◽  
Machining Conditions ◽  
Inverse Optimization Problem ◽  
Creep Feed Grinding ◽  
Creep Feed

This paper reports on the results of research on thermal aspects in the process of material removal by inverse heat transfer problem. The research focuses on the identification, modeling and optimization of machining process based on the measured temperature at a particular point of the workpiece. The inverse approach determines the overall temperature distribution of the workpiece and the unknown heat flux at the tool/workpiece interface in machining. By introducing and minimizing an objective function based on the heat flux function, relationship of the heating power and duration on the surface layer of the workpiece is optimized. In this way, the most favourable machining conditions are determined in order to achieve high productivity and quality levels. The inverse optimization problem is solved by using the analytical, numerical and regularization methods. Formulation, application and analysis of the inverse optimization problem of heat transfer are shown on the example of creep-feed grinding. The creep-feed grinding process is a widely used abrasive machining process that is characterized by high thermal load of the workpiece. The results of the inverse optimization problem were verified by a series of experiments under different machining conditions.

Experimental Measurement of Heat Transfer to a Cylinder Immersed in a Large Aviation-Fuel Fire

1973 ◽  
Vol 95 (3) ◽  
pp. 397-404 ◽  
Author(s):  
L. H. Russell ◽  
J. A. Canfield
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Radiant Heat ◽  
Aviation Fuel ◽  
Temperature History ◽  
Cylinder Surface ◽  
Measured Temperature ◽  
Convection Coefficient ◽  
Transfer Parameters ◽  
Experimental Effort

Presented are the results of an experimental effort to quantify some of the heat transfer parameters pertaining to the luminous flame that results from the uncontrolled combustion of an 8-ft × 16-ft pool of JP-5 aviation fuel. The temperature and effective total radiant heat flux, both as temporal mean quantities, were measured as functions of position within the quasi-steady burning flame as it existed in a quiescent atmosphere. A grid of infrared radiometers and radiation-shielded thermocouples served as the primary sensing equipment. A determination was made of the perimeter-mean convection coefficient applicable to a horizontally oriented, smooth, 8.530-in-dia circular cylinder immersed at a particular location within the JP-5 flame. The value of this coefficient was the result of a solution to a nonlinear, inverse conduction problem in which the convective heat flux at the cylinder surface was estimated by utilizing a measured temperature history inside the cylinder. An expression relating this coefficient to more general flame/cylinder systems was developed.

The Application of Enhanced Cooling Technology to Grinding Process

2013 ◽  
Vol 442 ◽  
pp. 36-39
Author(s):  
Ke Ma
Keyword(s):  
Heat Transfer ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Temperature ◽  
Creep Feed Grinding ◽  
Creep Feed ◽  
Surface Burning ◽  
New Type ◽  
Cooling Technology ◽  
The Comparative Study

An experimental study was performed to analyze the feasibility of heat pipe cooling in creep feed grinding applications. A new type of grinding wheel is developed to enhance the heat transfer of the grinding contact zone then decrease the grinding temperature. The performance of the new type grinding wheel was evaluated by measuring the grinding temperature when it was creep feed grinding the Ti-6Al-4V Alloy and the experimental results were compared with an ordinary grinding wheel. Results of the comparative study indicated that the use of enhanced cooling technology in a grinding wheel can decrease the grinding temperature significantly thus avoid the surface burning in grinding.

Approach to Heat Transfer Mechanism Beneath Boiling Bubble With MEMS Sensor

2009 ◽  
Author(s):  
Tomohide Yabuki ◽  
Osamu Nakabeppu
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Heated Surface ◽  
Bubble Nucleation ◽  
Temperature Data ◽  
Heated Wall ◽  
Measured Temperature ◽  
Back Side ◽  
Mems Sensor

Temperature variation beneath isolated bubble during saturated boiling of water was measured with a MEMS (Micro-Electro-Mechanical Systems) sensor having high temporal and spatial resolution. Then, local heat transfer from the heated surface was evaluated by a transient heat conduction analysis of the wall with measured temperature data as a boundary condition. The MEMS sensor on a 20 × 20 mm2 silicon substrate includes an electrolysis trigger and eight thin film thermocouples on the top side, and two thin film heaters on the back side. The thin film thermocouple was calibrated with a thermal scan method using two alloy samples with different melting point. The condition of the sensor was smoothly controlled with the heater. The bubble is initiated with electrolysis at a gap of the trigger electrode, where slight hydrogen gasses are supplied as bubble nuclei. Then, local and fast temperature variations in wide region are measured with the thermocouples with cutoff frequency of 100 kHz arranged in a line at 40 – 2000 μm far from the trigger gap. Measured temperature data presents formation of microlayer and expansion of dryout area in bubble growth process and rewetting in bubble departure process. The numerical analysis showed that average heat flux beneath the bubble indicated the maximum value of 19 W/cm2 during the microlayer evaporation, and then after hitting a bottom slightly lower than a heat flux at the bubble nucleation, recovers to the nucleation level. The contribution of the heat transfer from the heated wall was evaluated to approximately one-fourth of latent heat in the bubble at departure.

scholarly journals High Pressure Turbine Vane Annular Cascade Heat Flux and Aerodynamic Measurements With Comparisons to Predictions

1998 ◽  
Author(s):  
Christopher R. Joe ◽  
Xavier A. Montesdeoca ◽  
Friedrich O. Soechting ◽  
Charles D. MacArthur ◽  
Matthew Meininger
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Pressure ◽  
Heat Loss ◽  
Short Duration ◽  
Wall Temperature ◽  
Measured Temperature ◽  
Unique Contribution ◽  
Pressure Measurements ◽  
High Pressure Turbine

Experimental tests were performed at the USAF Turbine Research Facility (TRF) to obtain heat transfer and aerodynamic data on a first stage vane of a modern high pressure turbine. This is a transient blowdown facility that provides data from short duration tests. Data for a matrix of test conditions were obtained to document the effect of inlet Reynolds number, the stage pressure ratio across the vane, and the gas-to-wall temperature ratio. The objectives of these tests were to assess the capability of obtaining accurate aerodynamic total pressure loss measurements and airfoil static pressure measurements as well as determine the heat transfer coefficient distributions on the vanes. Results from these tests were compared to analytical predictions and are presented. The unique contribution of the work presented herein is: 1) demonstration of circumferential traversing temperature and pressure data in a short duration facility test, and 2) heat loss closure during a short duration test using heat flux gauges and the measured temperature loss. The transient heat loss during a short duration test is a fundamental requirement to determine turbine efficiency when work extraction is determined from the temperature drop across the turbine stage. Heat transfer data were acquired from heat flux gauges that were fabricated using thin-film sputtering techniques and placed on the airfoil surfaces. The surface temperature of the gauge was measured and heat flux was determined from a closed form transient semi-infinite solution that included the resistance of the heat flux gauge and the underlying metal substrate. Circumferentially, pressure measurements were obtained on the airfoil surfaces and on traversing rakes at the inlet and exit of the vane test section. Total and differential pressure rake instrumentation was required to obtain accurate aerodynamic loss measurements over a range of gas-to-wall temperature ratios.

Analysis of the Heat Transfer Coefficients on the Top of a Marine Diesel Piston Using the Inverse Heat Conduction Method

2011 ◽  
Vol 291-294 ◽  
pp. 1657-1661 ◽  
Author(s):  
Tao He ◽  
Xi Qun Lu ◽  
Yi Bin Guo
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Optimization Problem ◽  
Heat Conduction Problem ◽  
Inverse Heat Conduction Problem ◽  
Measured Temperature ◽  
Inverse Heat Conduction ◽  
Transfer Coefficients ◽  
Conduction Model ◽  
Marine Diesel

An efficient method utilizing the concept of inverse heat conduction is presented for the thermal analysis of pistons based on application to the piston head of a marine diesel engine. An inverse heat conduction problem is established in the form of an optimization problem. In the optimization problem, the convection heat transfer coefficient（HTC）on the top side of the piston is defined as the design variable, while the error between the measured and analysed temperatures is defined as objective function. For the optimization, an axi-symmetrical finite element conduction model is presented. The optimum distribution of the HTC at the top side of piston is successfully determined through a numerical implementation. The temperature obtained via an analysis using the optimum HTC is compared with the measured temperature, and reasonable agreement is obtained. The present method can be effectively utilized to analyze the temperature distribution of engine pistons.

Examining the LEED Rating System Using Approximate Inverse Optimization

2012 ◽  
Author(s):  
Sarina D. O. Turner ◽  
Timothy C. Y. Chan
Keyword(s):  
Optimization Problem ◽  
Historical Data ◽  
Green Building ◽  
The United States ◽  
Inverse Optimization ◽  
Rating System ◽  
Optimization Approach ◽  
Approximate Inverse ◽  
Design Elements ◽  
Inverse Optimization Problem

The Leadership in Energy and Environmental Design (LEED) rating system is the most recognized green building certification program in North America. In order to be LEED certified, a building must earn a certain number of points, which are obtained through achieving certain credits or design elements. Prior to LEED version 3, each credit was worth one point. In this study, we develop an inverse optimization approach to examine how building designers intrinsically valued design elements in LEED version 2. Due to the large dimensionality of the inverse optimization problem, we develop an approximation to improve tractability. We apply our method to 18 different LEED-certified buildings in the United States. We find that building designers did not value all credits equally and that other factors such as cost and certification level play a role in how the credits are valued. Overall, inverse optimization may provide a new method to assess historical data and support the design of future versions of LEED.

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