A modeling study on the effect of operating parameters on RHCM process using split flow channels design

2019 ◽  
Vol 20 (5) ◽  
pp. 503
Author(s):  
Fatma Kria ◽  
Moez Hammami ◽  
Mounir Baccar
Keyword(s):  
Flow Velocity ◽  
Cycle Time ◽  
Numerical Study ◽  
Cooling Water ◽  
Process Efficiency ◽  
Maximum Temperature ◽  
Coolant Temperature ◽  
Maximum Temperature Difference ◽  
Part Quality ◽  
Split Flow

In this work, a three-dimensional numerical study of thermal behavior of RHCM mold for automotive parts production was undertaken. Particularly, simulation of several heating/cooling cycles was conducted to determine, at the regular cyclic regime, thermal behaviors at cavity/core plates and polymer as well as thermal and hydrodynamic behaviors at cooling water. It was demonstrated that heating/cooling channels with split flow design are suitable for RHCM regulation. Besides, to further promote part quality, process productivity, and profitability, the effect of cooling parameters, such as the coolant temperature and flow velocity in channels, on the RHCM process efficiency was analyzed. To highlight the influence of these parameters on the productivity and profitability of the process, the cycle time and the consumed energy were used. Temperature gap at the cavity plate surfaces after the heating phase as well as the maximum temperature difference (MTD) in the polymer part after the cooling phase were used as criteria to evaluate the automotive part quality. The results show that the coolant temperature increase in the range between 30 and 60 °C reduces the energy consumption and improves the finished product quality with almost the same cycle time obtained by low coolant temperature. As regards to coolant flow velocity effect, an optimum value of about 1 m.s−1 improves part quality and provides a compromise between the cycle time and process profitability.

An Unsteady Analysis on Thermal Stratification in the SCS Piping Branched Off the RCS Piping

2003 ◽  
Author(s):  
Kwang-Chu Kim ◽  
Man-Heung Park ◽  
Hag-Ki Youm ◽  
Sun-Ki Lee ◽  
Tae-Ryong Kim ◽  
...  
Keyword(s):  
Temperature Difference ◽  
Thermal Stratification ◽  
Nuclear Power ◽  
Cooling System ◽  
Numerical Study ◽  
Outer Wall ◽  
Maximum Temperature ◽  
Rear Side ◽  
Maximum Temperature Difference ◽  
Starting Point

A numerical study is performed to estimate on an unsteady thermal stratification phenomenon in the Shutdown Cooling System (SCS) piping branched off the Reactor Coolant System (RCS) piping of Nuclear Power Plant. In the results, turbulent penetration reaches to the 1st isolation valve. At 500sec, the maximum temperature difference between top and bottom inner wall in piping is observed at the starting point of horizontal piping passing elbow. The temperature of coolant in the rear side of the 1st isolation valve disk is very slowly increased and the inflection point in temperature difference curve for time is observed at 2700sec. At the beginning of turbulent penetration from RCS piping, the fast inflow generates the higher temperature for the inner wall than the outer wall in the SCS piping. In the case the hot-leg injection piping and the drain piping are connected to the SCS piping, the effect of thermal stratification in the SCS piping is decreased due to an increase of heat loss compared with no connection case. The hot-leg injection piping affected by turbulent penetration from the SCS piping has a severe temperature difference that exceeds criterion temperature stated in reference. But the drain piping located in the rear compared with the hot-leg injection piping shows a tiny temperature difference. In a viewpoint of designer, for the purpose of decreasing the thermal stratification effect, it is necessary to increase the length of vertical piping in the SCS piping, and to move the position of the hot-leg injection piping backward.

Model and Imitation of the Cycle Temperature Fields and Deformations of Coke Drum

2011 ◽  
Vol 197-198 ◽  
pp. 1389-1394
Author(s):  
Sun Yi Chen
Keyword(s):  
Temperature Field ◽  
Temperature Difference ◽  
Cooling Water ◽  
Physical Property ◽  
Temperature Fields ◽  
Maximum Temperature ◽  
Kinetic Temperature ◽  
Maximum Temperature Difference ◽  
Radial Temperature ◽  
Inside Wall

When the operating process of delay coking is cyclically changing from 25°C to 500°C, it would usually induce the effect of heat treatment on the shell of coke drum. After a special model of the kinetic medium climbing along the inside-wall of the coke drum at a steady rate set up, the resulting two-dimensional kinetic temperature field of shell in radial and axial directions has been calculated and analyzed by FEM. The relation between the material physical property of the shell and its temperature has been considered. The results show that the radial temperature difference or the axial temperature difference caused by the cooling water is more than that caused by the hot oil. The maximum temperature difference between the inside-wall and the outside-wall is 40°C below the medium level, 30mm by the hot oil and 60 °C or 25 mm by the cooling water. The circumferential uneven temperature field, location and concave/convex or incline/bend of body have been surveyed and analyzed. The lat-circle deformation of transverse section has been discussed.

Thermal Management of a Li-Ion Battery for Electric Vehicles Using PCM and Water-Cooling Board

2019 ◽  
Vol 814 ◽  
pp. 307-313
Author(s):  
Gu Yu Yu ◽  
Sum Wai Chiang ◽  
Wei Chen ◽  
Hong Da Du
Keyword(s):  
Thermal Management ◽  
Heat Dissipation ◽  
Cooling Water ◽  
Optimum Operating ◽  
Maximum Temperature ◽  
Li Ion Battery ◽  
Optimum Operating Temperature ◽  
Maximum Temperature Difference ◽  
Li Ion ◽  
Battery Module

A novel thermal management system (TMS) for Li-ion battery module using phase change material (PCM) and cooling water as the heat dissipation source to control battery temperature rise has been developed. Graphite sheets were applied to compensate low thermal conductivity of battery and PCM and improve temperature uniformity of the batteries. One discharge (1C rate)-charge (2C rate) circle was applied in battery modules to test the effectiveness of this TMS. A three dimensional numerical model of the battery module with the TMS was conducted. The results show that this TMS basically meets the demand about the maximum temperature difference of battery module and totally keeps the maximum temperature within the optimum operating temperature range (≤45°C).

Numerical Simulation of Turbulent Heat Transfer on a Rotating Disk With an Impinging Jet

2010 ◽  
Author(s):  
M. H. Saidi ◽  
H. Karrabi ◽  
H. B. Avval ◽  
A. Asgarshamsi
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Rotating Disk ◽  
Turbulent Heat Transfer ◽  
Maximum Temperature ◽  
Turbulent Heat ◽  
Cooling Process ◽  
Maximum Temperature Difference

A numerical study has been earned out to investigate the fluid flow structure and convective heat transfer due to a circular jet impinging on a rotating disk. The temperature distribution and convection heat transfer coefficient on the disk are calculated. Flow is considered to be steady, incompressible and turbulent. k-ε RNG model is used to model the turbulent flow. Two new criteria are introduced and used to evaluate the performance of cooling process which are maximum temperature difference on the disk and the average temperature of the disk. The first parameter shows the uniformity of temperature distribution in the disk and the second shows the effect of both thermo physical properties of the disk material and cooling process. In order to verify the numerical approach, results have been compared with the experimental data which shows a good agreement.

scholarly journals Seasonal Variations of Daytime Land Surface Temperature and Their Underlying Drivers over Wuhan, China

2021 ◽  
Vol 13 (2) ◽  
pp. 323
Author(s):  
Liang Chen ◽  
Xuelei Wang ◽  
Xiaobin Cai ◽  
Chao Yang ◽  
Xiaorong Lu
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Maximum Temperature ◽  
Maximum Temperature Difference ◽  
Rapid Urbanization ◽  
The Impact ◽  
The City

Rapid urbanization greatly alters land surface vegetation cover and heat distribution, leading to the development of the urban heat island (UHI) effect and seriously affecting the healthy development of cities and the comfort of living. As an indicator of urban health and livability, monitoring the distribution of land surface temperature (LST) and discovering its main impacting factors are receiving increasing attention in the effort to develop cities more sustainably. In this study, we analyzed the spatial distribution patterns of LST of the city of Wuhan, China, from 2013 to 2019. We detected hot and cold poles in four seasons through clustering and outlier analysis (based on Anselin local Moran’s I) of LST. Furthermore, we introduced the geographical detector model to quantify the impact of six physical and socio-economic factors, including the digital elevation model (DEM), index-based built-up index (IBI), modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), population, and Gross Domestic Product (GDP) on the LST distribution of Wuhan. Finally, to identify the influence of land cover on temperature, the LST of croplands, woodlands, grasslands, and built-up areas was analyzed. The results showed that low temperatures are mainly distributed over water and woodland areas, followed by grasslands; high temperatures are mainly concentrated over built-up areas. The maximum temperature difference between land covers occurs in spring and summer, while this difference can be ignored in winter. MNDWI, IBI, and NDVI are the key driving factors of the thermal values change in Wuhan, especially of their interaction. We found that the temperature of water area and urban green space (woodlands and grasslands) tends to be 5.4 °C and 2.6 °C lower than that of built-up areas. Our research results can contribute to the urban planning and urban greening of Wuhan and promote the healthy and sustainable development of the city.

Numerical study of the aerodynamic and power characteristics of the cycloidal rotor, under incoming flow

2019 ◽  
pp. 25-34
Author(s):  
Александр Анатольевич Дектерев ◽  
Артем Александрович Дектерев ◽  
Юрий Николаевич Горюнов
Keyword(s):  
Flow Velocity ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
Incoming Flow ◽  
Ansys Fluent ◽  
Energy Characteristics ◽  
Power Characteristics ◽  
Calculation Results

Исследование направлено на разработку и апробацию методики численного моделирования аэродинамических и энергетических характеристик циклоидального ротора. За основу взята конфигурация ротора IAT21 L3. Для нее с использованием CFD-пакета ANSYS Fluent построена математическая модель и выполнен расчет. Проанализировано влияние скорости набегающего потока воздуха на движущийся ротор. Математическая модель и полученные результаты исследования могут быть использованы при создании летательных аппаратов с движителями роторного типа. This article addresses the study of the aerodynamic and energy characteristics of a cycloidal rotor subject to the influence of the incoming flow. Cycloidal rotor is one of the perspective devices that provide movement of aircrafts. Despite the fact that the concept of a cycloidal rotor arose in the early twentieth century, the model of a full-scale aircraft has not been yet realized. Foreign scientists have developed models of aircraft ranging in weight from 0.06 to 100 kg. The method of numerical calculation of the cycloidal rotor from the article [1] is considered and realized in this study. The purpose of study was the development and testing of a numerical simulation method for the cycloidal rotor and study aerodynamic and energy characteristics of the rotor in the hovering mode and under the influence of the oncoming flow. The aerodynamic and energy characteristics of the cycloidal rotor, rotating at a speed of 1000 rpm with incoming flow on it with velocities of 20-80 km/h, were calculated. The calculation results showed a directly proportional increase of thrust with an increase of the incoming on the rotor flow velocity, but the power consumed by the rotor was also increased. Increase of the incoming flow velocity leads to the proportional increasing of the lift coefficient and the coefficient of drag. Up to a speed of 80 km/h, an increase in thrust and power is observed; at higher speeds, there is a predominance of nonstationary effects and difficulties in estimating the aerodynamic characteristics of the rotor. In the future, it is planned to consider the 3D formulation of the problem combined with possibility of the flow coming from other sides.

MODELING THE EFFECT OF HEAT EXCHANGE ON THE EFFICIENCY OF A THERMOELECTRIC COOLER

2020 ◽  
Vol 2 ◽  
pp. 132-135
Author(s):  
O.I. MARKOV
Keyword(s):  
Numerical Calculation ◽  
Heat Exchange ◽  
Solid State ◽  
Numerical Modelling ◽  
Temperature Difference ◽  
Maximum Temperature ◽  
Thermoelectric Cooler ◽  
Maximum Temperature Difference ◽  
Peltier Cooler ◽  
Account Heat

Numerical modelling thermal and thermoelectric processes in a branch of solid–state thermoelectric of Peltier cooler is performed, taking into account heat exchange by convection and radiation. The numerical calculation of the branch was carried out in the mode of the maximum temperature difference.

Numerical Study of Particle Behaviour in Split-Flow Thin-Channel Fractionation Using the Discrete Element Method

2008 ◽  
Vol 43 (11-12) ◽  
pp. 2981-3002 ◽  
Author(s):  
Myhuong Nguyen ◽  
Martin Rhodes ◽  
Kurt Liffman ◽  
Ian McKinnon ◽  
Ron Beckett
Keyword(s):  
Discrete Element Method ◽  
Numerical Study ◽  
Discrete Element ◽  
Split Flow ◽  
Thin Channel ◽  
Particle Behaviour ◽  
Element Method

Effect of Periodic Imposed Heat Flux on Three-Dimensional Natural Convection in a Partially Heated Cubical Enclosure

2016 ◽  
Vol 831 ◽  
pp. 83-91
Author(s):  
Lahoucine Belarche ◽  
Btissam Abourida
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Study ◽  
Control Volume ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Cubical Enclosure ◽  
Simplec Algorithm ◽  
Volume Method

The three-dimensional numerical study of natural convection in a cubical enclosure, discretely heated, was carried out in this study. Two heating square sections, similar to the integrated electronic components, are placed on the vertical wall of the enclosure. The imposed heating fluxes vary sinusoidally with time, in phase and in opposition of phase. The temperature of the opposite vertical wall is maintained at a cold uniform temperature and the other walls are adiabatic. The governing equations are solved using Control volume method by SIMPLEC algorithm. The sections dimension ε = D / H and the Rayleigh number Ra were fixed respectively at 0,35 and 106. The average heat transfer and the maximum temperature on the active portions will be examined for a given set of the governing parameters, namely the amplitude of the variable temperatures a and their period τp. The obtained results show significant changes in terms of heat transfer, by proper choice of the heating mode and the governing parameters.

scholarly journals A study of improving thermal environment of external louver through establishment of test bed

2018 ◽  
Vol 7 (3.3) ◽  
pp. 373
Author(s):  
Sun Pil Kwon ◽  
Jae Jun Jung ◽  
Byoung Jo Jung
Keyword(s):  
Statistical Analysis ◽  
Solar Radiation ◽  
Thermal Effect ◽  
Thermal Load ◽  
Thermal Environment ◽  
Direct Solar Radiation ◽  
Maximum Temperature ◽  
Test Bed ◽  
Solar Insolation ◽  
Maximum Temperature Difference

Background/Objectives: To improve a thermal load by increasing internal thermal effect of a building from direct solar radiation through an increase of glass windows.Methods/Statistical analysis: Through the establishment of test beds of the same size, the data of temperature, humidity, solar insolation and PMV of each test bed with or without external louver are acquired to analyze thermal environmental with the simulation.Findings: For the analysis of thermal environment, the amount of energy consumption has been analyzed through the simulation and the data of temperature, humidity, solar insolation and PMV have been acquired for the analysis. With the simulation, about 20% energy saving has been confirmed and the daily averages of temperature and humidity between 8AM to 7PM have been calculated to calculate the maximum temperature difference to be 9.4℃. The solar insolation between 9AM and 7PM was 300W/m2 or below.Improvements/Applications: The improvement of thermal effect with an external louver has been confirmed. It may be applied to the louver system to improve building thermal environment, awning to control direct solar radiation, blind to improve uniformity of illumination intensity toward building during daytime, external blind and ceiling louver system. 

Sign in / Sign up

Export Citation Format

Share Document