Numerical Simulation Model of Electrothermal De-Icing Process on Composite Substrate

2020 ◽  
Author(s):  
Xiaofeng Guo ◽  
Zhiqiang Guo ◽  
Qian Yang ◽  
Wei Dong
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Thermal Properties ◽  
Temperature Distribution ◽  
Simulation Model ◽  
Melting Process ◽  
Ice Melting ◽  
Melted Zone ◽  
Composite Substrate ◽  
Cfrp Composite

Abstract A numerical simulation model of electrothermal de-icing process on carbon fiber reinforced polymer (CFRP) composite is conducted to study the effect of thermal properties of the substrate on the ice melting process. A novel melting model which is based on the enthalpy-porosity method is applied to study the transient ice melting process and heat transfer of the de-icing sys-tem. Multi-layered electrothermal de-icing systems including composites with different fiber orientation are used to analyze the effects of orthotropic heat conductivity of the CFRP composite on the ice melting process and heat transfer. Movement of the ice-water interface, the melted zone thickness and the melted zone area on CFRP composite are investigated on the three-dimensional electrothermal de-icing unit. The effects of thermal properties of substrate on the temperature distribution of the ice-airfoil interface are analyzed. The computational results show that the thermal properties of substrates affect the temperature on the ice-airfoil interface, the temperature distribution in the substrate, ice melting area, ice melting rate and ice melting volume significantly. The time that ice starts to melt on the CFRP composite substrate is earlier than that on the metal substrate. However, it takes more time for the ice to melt completely on the ice-CFRP interface than that on the ice-metal inter-face. The orthotropic heat conductivity of CFRP composite results in strong directivity of the melting area on the ice-CFRP in-terface. A ratio parameter is defined to represent the matching degree of substrate materials and geometry model of de-icing system. The simulation model can be applied to study electrothermal de-icing system of nacelle inlet and airfoil made of composite. The results in present work is also helpful to predict the change of temperature during de-icing process and provide guidelines for the optimizing the electrothermal de-icing system to reduce power consumption according to the fiber structure of composite.

Experimental and Numerical Evaluation of Small-Scale Cryosurgery Using Ultrafine Cryoprobe

2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Junnosuke Okajima ◽  
Atsuki Komiya ◽  
Shigenao Maruyama
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Numerical Evaluation ◽  
Small Scale ◽  
Outer Diameter ◽  
Cooling Performance ◽  
The Heat Transfer Coefficient

The objective of this work is to experimentally and numerically evaluate small-scale cryosurgery using an ultrafine cryoprobe. The outer diameter (OD) of the cryoprobe was 550 μm. The cooling performance of the cryoprobe was tested with a freezing experiment using hydrogel at 37 °C. As a result of 1 min of cooling, the surface temperature of the cryoprobe reached −35 °C and the radius of the frozen region was 2 mm. To evaluate the temperature distribution, a numerical simulation was conducted. The temperature distribution in the frozen region and the heat transfer coefficient was discussed.

scholarly journals Prediction of Convective Heat Transfer Coefficient and Temperature Distribution of Air-Conditioned Spaces Using Numerical Simulation

2016 ◽  
Vol 10 (8) ◽  
pp. 12
Author(s):  
Hussein J. Akeiber ◽  
Mazlan A. Wahid ◽  
Hasanen M. Hussen ◽  
Abdulrahman Th. Mohammad ◽  
Bashar Mudhaffar Abdullah ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Solution Technique ◽  
Geometrical Parameters

Accurate and efficient modeling of convective heat transfer coefficient (CHTC) by considering the detailed room geometry and heat flux density in building is demanding for economy, environmental amiability, and user satisfaction. We report the three-dimensional finite-volume numerical simulation of internal room flow field characteristics with heated walls. Two different room geometries are chosen to determine the CHTC and temperature distribution. The conservation equations (elliptic partial differential) for the incompressible fluid flows are numerically solved using iterative method with no-slip boundary conditions to compute velocity components, pressure, temperature, turbulent kinetic energy, and dissipation rate. A line-by-line solution technique combined with a tri-diagonal matrix algorithm (TDMA) is used. The temperature field is simulated for various combinations of air-change per hour and geometrical parameters. The values of HTCs are found to enhance with increasing wall temperatures.

Numerical Simulation of Cathode Erosion in EDM Process

2012 ◽  
Vol 462 ◽  
pp. 109-115
Author(s):  
Zhen Long Wang ◽  
Bao Cheng Xie ◽  
Yu Kui Wang ◽  
Wan Sheng Zhao
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Heat Flux ◽  
Finite Element ◽  
Thermal Properties ◽  
Temperature Distribution ◽  
Material Removal ◽  
Cathode Erosion ◽  
Gauss Distribution ◽  
Edm Process

A numerical model of cathode erosion in EDM process using finite element method is presented. Using this model, numerical simulation of the single spark of EDM process has been carried out with parameters such as conduction, convection, the latent heat of phase change, thermal properties of material with temperature and gauss distribution of heat flux to predict the temperature distribution in the discharge point of cathode as a result of single discharges in EDM process. The simulation result shows the trend of dynamic temperature distribution of heat -affected zone and well explains mechanism of material removal in EDM process.

Simulation and Research of a Thermal Type Liquid Flow Sensor

2012 ◽  
Vol 562-564 ◽  
pp. 1213-1217
Author(s):  
Feng Tian ◽  
Zhen Bin Gao ◽  
Yi Cai Sun
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchange ◽  
Temperature Distribution ◽  
Flow Sensor ◽  
Turbulent Heat Transfer ◽  
Turbulent Heat ◽  
Water Flow Velocity ◽  
Detection Circuit ◽  
Flow Detection

A flow sensor for liquids, based on the principle of fluid-structure heat transfer is presented. The heater and thermistor are integrated and wrapped together as a detector and heat source, allowing heat exchange between the sensor and the fluid. Through numerical simulation, the temperature distribution of the sensor was investigated, under conditions of various flow velocities. The process of turbulent heat transfer in the flow pipe was simulated, the temperature distribution in the sensor was analyzed and compared under different temperature and velocity of the fluid, and the corresponding measuring ranges were determined. The flow detection circuit is designed and the results of water flow velocity tests in the range of (0.01–1)m/s are presented.

scholarly journals Thermal Analysis-Based Field Validation of the Deformation of a Recycled Base Course Made with Innovative Road Binder

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5925
Author(s):  
Grzegorz Mazurek ◽  
Przemysław Buczyński ◽  
Marek Iwański ◽  
Marcin Podsiadło
Keyword(s):  
Numerical Simulation ◽  
Thermal Properties ◽  
Temperature Distribution ◽  
Cross Section ◽  
Thermal Analyses ◽  
The Road ◽  
Laboratory Test Results ◽  
Base Course ◽  
On The Road ◽  
Foamed Bitumen

The deformation of the cold recycled mixture with foamed bitumen in a recycled base with an innovative three-component road binder and foamed bitumen is analysed. Numerical simulation results for the pavement constructed, based on laboratory test results, were verified against the data from the monitoring system installed on the road trial section. In addition, environmental effects, such as air temperature and humidity levels in the pavement structure layers, were considered. Thermal analyses were conducted to identify the thermal properties of the pavement materials under steady heat transfer rate. Determining temperature distribution in the road cross-section in combination with relaxation functions determined for individual pavement layers contributed to the high effectiveness of the numerical simulation of deformation and displacement in the recycled base and the entire pavement. The experimental method of identifying thermal properties allows a fast and satisfactory prediction of temperature distribution in the pavement cross-section.

Numerical Simulation of Paraffin Melting Process in an Inclined Channel

2021 ◽  
Vol 896 ◽  
pp. 111-116
Author(s):  
Yan Li ◽  
Guo You You ◽  
Zhu Qunzhi
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Early Stage ◽  
Liquid Paraffin ◽  
Convection Heat Transfer ◽  
Melting Process ◽  
Heat Transfer Mode ◽  
Dominant Position ◽  
Transfer Mode ◽  
Higher Temperature

Numerical simulation of the melting of paraffin in the inclined straight channel shows that the melting speed of paraffin is faster in the early stage and gradually slows down in the later stage. It is found that heat conduction is the main heat transfer mode in the early stage of paraffin melting. With the increasing number of liquid paraffin, natural convection occurs in the liquid paraffin. The liquid paraffin with higher temperature flows upward due to the effect of buoyance and lift, and convection heat transfer gradually increases and takes the dominant position in the melting process.

Estimation of Undisturbed Geothermal Gradient in Wells From Measured Drilling Data: A Numerical Approach

2017 ◽  
Author(s):  
Lucas Cantinelli Sevillano ◽  
Jesus De Andrade ◽  
Sigbjørn Sangesland
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Temperature Distribution ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Geothermal Gradient ◽  
Computer Code ◽  
Numerical Approach ◽  
Rock Properties ◽  
Drilling Fluids

The undisturbed geothermal gradient is a key thermal boundary that drives heat transfer processes occurring in oil and gas wells throughout their lifetime. However, the temperature distribution with depth is somewhat uncertain, and this is often assumed to be a linear approximation from the mudline to the bottom of the well. During drilling, the circulating temperature may significantly affect the rheology of the drilling fluids and the cement setting processes. Therefore, erroneous estimates of the wellbore temperature may affect the overall performance of the drilling phase and subsequent well operations. Further, it is important to know the accurate temperature distribution within the formation for assessment of the petroleum prospectivity through source rock maturation and reservoir quality. This paper presents a numerical methodology to estimate the undisturbed geothermal gradient while drilling in offshore wells. This methodology may also be applied to onshore wells by simplification. The new approach is based on an in-house axisymmetric wellbore transient thermal model, in which the equations are solved using the finite difference method. The model computes the heat transfer between the well and riser system with the surroundings. However, other computational codes may also be used following the framework presented in this study. The computer code should provide a detailed representation of the geometry of the wellbore, the physical properties of the drilling fluid and formation, the suitable thermal boundary conditions and temporal discretization. The temperatures of the fluid at the inlet of the drillstring and at the bottom hole assembly (BHA), in the annulus A, are used as input to the numerical model that iteratively adjusts the undisturbed geothermal gradient, which generated the temperature recordings while drilling. The paper comprises cases studies of hypothetical wells drilled in relevant offshore areas in the world, each with their distinctive and variable geothermal gradient, defined by the different rock formations encountered. Uncertainties regarding the thermal properties of the rock were also considered to ascertain the robustness of the code. The water depth of the drilling site was also observed to impact the convergence of the algorithm. The results obtained by the numerical approach are in good agreement with the expected values of the undisturbed formation temperatures. The novelty of the numerical framework is the ability to provide reliable and satisfactory estimates of the undisturbed geothermal gradient for wellbores with any configuration, lithology and rock properties. These estimates are based on temperature measurements of the circulating drilling fluid at the BHA and account for uncertainty in rock thermal properties; in reasonable time using standard engineering computers.

scholarly journals A Study on the Void Formation in Residual Wall Thickness of Fluid-Assisted Injection Molding Parts

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Hyung-Pil Park ◽  
Baeg-Soon Cha ◽  
Soo-Bin Park ◽  
Jae-Hyuk Choi ◽  
Dong-Han Kim ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Temperature Distribution ◽  
Injection Molding ◽  
Temperature Change ◽  
Wall Thickness ◽  
Silicone Oil ◽  
Void Formation ◽  
Heat Transfer Analysis ◽  
Hollow Section

In fluid-assisted injection molding, the distribution of the residual wall thickness on the inside and outside of the curved area is different, and void is formed due to the effect of the shrinkage on the outside where the residual wall thickness is thicker. The shrinkage that takes place in the residual wall is affected by the rheological changes in the polymer caused by temperature change and also by the thermal properties of the penetration fluid. In this study, the different effects on void formation in residual wall during fluid-assisted injection molding were analyzed, and water and silicone oil that had different thermal properties were used for the fluids. For this, heat transfer analysis and injection molding analysis were conducted. The void formation occurred due to the different temperature distribution and volumetric shrinkage in the direction of the residual wall in the curved area with a hollow section. It was also found that the void formation in the curved area decreased in the case of silicone oil compared to the case of water from simulation and experiments.

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