CFD Heat Transfer Investigation Into the Convective Coefficient of a Perforated Plate

2005 ◽  
Author(s):  
Andrew M. Hayes ◽  
Jamil A. Khan ◽  
Ian G. Spearing ◽  
Aly Shaaban
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer Coefficient ◽  
Perforated Plate ◽  
Upstream Face ◽  
Cfd Model ◽  
Plate Temperature ◽  
Convective Coefficient ◽  
Perforated Sheet ◽  
Exit Temperature ◽  
Computational Fluid Dynamics Cfd

A computational fluid dynamics (CFD) model investigating the heat transfer convective coefficient of the upstream face, the upstream face and the tube face, and the upstream face, tube face, and leeward face of a perforated sheet was developed. This model was based on the hexagonally shaped flow pattern that exists around each of the holes in a perforated sheet of a certain pitch to diameter ratio. The CFD model used in the investigation of the convective heat transfer coefficient involved a single hole in a thin hexagonally shaped sheet with appropriate boundary conditions. Through a series of models varying the inlet velocity, hole diameter, and the plate temperature and then solving for the exit temperature the convective coefficient could be obtained. After obtaining the convective coefficient, the Nusselt number was calculated. These values were then plotted against the Reynolds number and an equation for the line was obtained of the form: Nu=C1·ReC2(1)

Experimentation and modeling of convective heat transfer coefficient for evaporation of liquid foods in a pilot plant double effect

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Reyes Carlos Macedo y Ramírez ◽  
Jorge Fernando Vélez Ruiz
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Process Design ◽  
Food Industry ◽  
Convective Heat Transfer Coefficient ◽  
Double Effect ◽  
Sugar Solution ◽  
Convective Coefficient ◽  
Common Process ◽  
Predicted Values

Abstract Even though the evaporation is a common process in the food industry, there is scarce information about the convective coefficient evaluation as an important parameter for equipment and process design. A research on evaporation of sugar solution in a double effect was carried out. The experimental results obtained in this equipment, from the heat transfer and concentration processes are presented, a range of 2658–6091 W of heat flow was quantified implying computed values of 1431–3763 W/m2K for the convective coefficients and 1020–1815 W/m2K for the overall coefficient. The quantification of the convective coefficient, the fitting methodology and modeling were developed in order, to obtain the correspondent correlations. Then, from a set of several equations, two general relationships are proposed. Both correlations were applied to experimental and supposed data, finding a difference lower than 30% between the experimental and predicted values of the Nusselt number, that was considered as satisfactory.

Characteristics of Heat Transfer During Cooling Down Process in a Single Cargo Tank of LNG Carrier

2020 ◽  
Vol 162 (A3) ◽  
Author(s):  
J J Deng ◽  
L Y Song ◽  
J Xu ◽  
B Liu ◽  
J S Lu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Deep Understanding ◽  
Liquefied Natural Gas ◽  
Cfd Model ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Computational Fluid Dynamics Cfd ◽  
Heat Transfer Simulation ◽  
Lng Tank

A deep understanding of heat transfer characteristics is essential in evaluating risk and putting forward any option for the Liquefied Natural Gas (LNG) tank cooling down process. A novel Computational Fluid Dynamics (CFD) model was built to perform the flow and heat transfer simulation of the process. The predicted results agreed well with the test data from a prototype LNG tank. Then the heat transfer characteristics of the process were analysed. It was found that the vapour temperature and density were linearly varying and became stable after 2.3 hours. A sudden pressure drop risk was identified during the process, which will cause the inwards collapse risk of the invar membrane. Then the proposals to prevent the risks of the inwards collapsing membrane are presented. The heat transfer characteristics of the vapour and different membrane layers were analysed in detail, and if the suggested option was to be implemented this could save about 39% of LNG consumed.

Assessment of Heat Transfer and Airflow Characteristics in Air-Conditioned Room: 3D Time-Dependent Model

2004 ◽  
Author(s):  
Ramiz Kameel ◽  
Essam E. Khalil
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Time Dependent ◽  
Design System ◽  
Cfd Model ◽  
Dependent Model ◽  
Recirculation Zones ◽  
Computational Fluid Dynamics Cfd ◽  
Time Dependent Model

Airflow characteristics in ventilated and air-conditioned spaces play an important role to attain comfort and hygiene conditions. This paper utilizes a 3D time-dependent Computational Fluid Dynamics (CFD) model to assess the airflow characteristics in different air-conditioned spaces. It is found that the optimum airside design system can be attained, if the airflow is directed to pass all the enclosure areas before the extraction. Still most of these factors and evaluation indices have the shortage of adequately describe the influence of the recirculation zones on the occupancy zone and also on the fresh supplied air. The model of evaluation should assess the airflow characteristics in any enclosure according to its position in the enclosure and the expected target of it along its pass to the extraction.

Investigation of Pressure Dependent Thermal Contact Resistance between Silver Metallized SiC Chip and DBC Substrate

2015 ◽  
Vol 821-823 ◽  
pp. 452-455 ◽  
Author(s):  
Zsolt Toth Pal ◽  
Ya Fan Zhang ◽  
Ilja Belov ◽  
Hans Peter Nee ◽  
Mietek Bakowski
Keyword(s):  
Heat Transfer ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Cfd Simulation ◽  
Thermal Contact ◽  
Cfd Model ◽  
Transfer Experiment ◽  
Transfer Path ◽  
Computational Fluid Dynamics Cfd ◽  
Pressure Independent

– Thermal contact resistances between a silver metallized SiC chip and a direct bonded copper (DBC) substrate have been measured in a heat transfer experiment. A novel experimental method to separate thermal contact resistances in multilayer heat transfer path has been demonstrated. The experimental results have been compared with analytical calculations and also with 3D computational fluid dynamics (CFD) simulation results. A simplified CFD model of the experimental setup has been validated. The results show significant pressure dependence of the thermal contact resistance but also a pressure independent part.

Large Eddy Simulation of Conjugate Heat Transfer Around a Multi-Perforated Plate With Deviation

2016 ◽  
Author(s):  
Dorian Lahbib ◽  
Antoine Dauptain ◽  
Florent Duchaine ◽  
Franck Nicoud
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Large Eddy Simulation ◽  
Conjugate Heat Transfer ◽  
Pressure Ratio ◽  
Perforated Plate ◽  
Inlet Temperature ◽  
Plate Temperature ◽  
Eddy Simulation ◽  
Large Eddy

To improve gas turbine efficiency, engine manufacturers increase both the overall compressor pressure ratio and the turbine inlet temperature, resulting into a higher thermal load of the combustion chamber walls. Cooling systems such as multi-perforated plates are in this context good candidates to lower the thermal constraints on the liners. Such technological devices consist in introducing, through submillimetric holes, a cold air flow into the boundary layer of the chamber wall. Though commonly used in industrial applications, perforations with an angle of deviation, i.e. not aligned with the main flow, have not been studied in most experimental and numerical studies. The deviation angle impacts the liner temperature by modifying the flow structure around the plate. Conjugate heat transfer computations coupling Large Eddy Simulation and heat conduction are performed on streamwise and 45 angled configurations composed of 12 rows at an operating point representative of helicopter combustors to analyze the effect of the deviation. The flow organization around the plate is modified, yielding different heat flux distribution and plate temperature. The major differences are observed within the perforations where the heat flux coefficient increases up to 54% in the configuration with deviation.

scholarly journals Simulation Study of LPG Cooking Burner

2018 ◽  
Vol 7 (3.7) ◽  
pp. 142 ◽  
Author(s):  
Mana Wichangarm ◽  
Anirut Matthujak ◽  
Thanarath Sriveerakul ◽  
Sedthawatt Sucharitpwatskul ◽  
Sutthisak Phongthanapanich
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Flame Structure ◽  
Three Dimensional ◽  
Cfd Model ◽  
Flow Feature ◽  
Combustion Region ◽  
Computational Fluid Dynamics Cfd ◽  
The Heat Transfer Coefficient ◽  
Good Agreement

The objective of this paper is to numerically study the flow feature and combustion phenomena of an energy-saving cooking burner using three-dimensional computational fluid dynamics (CFD). Combustion temperatures were experimentally and numerically investigated in order to not only validate the CFD model, but also describe the combustion phenomena. From the temperature comparison, the CFD model was good agreement with the experiment, having the error of less than 5.86%. Based upon the insight from the CFD model, the high temperature of 1,286 K occurred at the middle of the burner. The high intensive vortex of the flow being enhanced the combustion intensity and the heat transfer coefficient is obvious observed near the burner head inside the ring. Therefore, it is concluded that the burner ring is the major part since it controls flame structure, high temperature region, intensive combustion region, heat loss and suitable flow feature. However, heat transfer to the vessel should be further clarified by the CFD model.   

CFD Simulation of Heat Transfer of Pulsating Gas in a Pipe

2014 ◽  
Vol 687-691 ◽  
pp. 623-626
Author(s):  
Zhi Ren Yin ◽  
Li Jun Yang ◽  
Run Ze Duan
Keyword(s):  
Heat Transfer ◽  
Cfd Simulation ◽  
Cfd Model ◽  
Pulse Combustor ◽  
Flow Development ◽  
Steady Flow Condition ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
High Level ◽  
The Heat Transfer Coefficient

Numerical Simulation of pulsating flow in a pulse combustor tailpipe was performed using computational fluid dynamics (CFD) method. The flow in the pipe was characterized by periodic pulsating. The influence of this pulsating includes incomplete flow development and high level of convective heat transfer rate, and both were considered and investigated by the CFD model. Compared with the steady flow condition, results showed that the heat transfer coefficient and Nusselt number were 2.35 times higher.

Investigation of Heat Transfer Phenomena in Blast Furnace Tuyere/Blowpipe Region

2017 ◽  
Author(s):  
Xiang Liu ◽  
Guangwu Tang ◽  
Tyamo Okosun ◽  
Armin K. Silaen ◽  
Stuart J. Street ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Blast Furnace ◽  
Operating Conditions ◽  
Cfd Model ◽  
Pulverized Coal Injection ◽  
Steel Making ◽  
Computational Fluid Dynamics Cfd ◽  
Tuyere Region ◽  
Multi Mode ◽  
Fuel Source

The blast furnace (BF) is a crucial stage in the iron-steel making process. Pulverized coal injection (PCI) and natural gas (NG) have been utilized in blast furnaces as a substitute fuel source for reducing coke rate. Due to introduction of injected fuels into a blast furnace, the combustion and heat transfer in the tuyere/blowpipe region affects the tuyere/blowpipe structure. A comprehensive computational fluid dynamics (CFD) model including PCI/NG combustion, multi-mode heat transfer for the blowpipe/tuyere region of a blast furnace at AK Steel Dearborn Works has been developed, considering detailed material properties in the blowpipe region. The model has been validated by comparing the blowpipe skin temperature profile with thermographic images under typical operating conditions. Based on the developed CFD model, the detailed PCI/NG co-injection combustion has been investigated and the thermal effect on the tuyere tip has been revealed.

scholarly journals Modeling and simulation of forced-air cooling of strawberries using variable convective coefficient

2012 ◽  
Vol 32 (1) ◽  
pp. 164-173 ◽  
Author(s):  
Álvaro J. H. Siqueira ◽  
Andréa O. da Costa ◽  
Esly F. da Costa Junior
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Heat Transfer Process ◽  
Air Cooling ◽  
Cooling Process ◽  
Experimental Conditions ◽  
Convective Coefficient ◽  
Forced Air

In the forced-air cooling process of fruits occurs, besides the convective heat transfer, the mass transfer by evaporation. The energy need in the evaporation is taken from fruit that has its temperature lowered. In this study it has been proposed the use of empirical correlations for calculating the convective heat transfer coefficient as a function of surface temperature of the strawberry during the cooling process. The aim of this variation of the convective coefficient is to compensate the effect of evaporation in the heat transfer process. Linear and exponential correlations are tested, both with two adjustable parameters. The simulations are performed using experimental conditions reported in the literature for the cooling of strawberries. The results confirm the suitability of the proposed methodology.

Flow Regimes and Heat Transfer Patterns in Archeological Climatized Church of Christ, Cairo

2012 ◽  
Author(s):  
Essam E. Khalil
Keyword(s):  
Heat Transfer ◽  
Church Of Christ ◽  
Design System ◽  
Wall Paintings ◽  
Careful Selection ◽  
Cfd Model ◽  
Thermal Pattern ◽  
Recirculation Zones ◽  
Computational Fluid Dynamics Cfd ◽  
Selection Of

Airflow characteristics in ventilated and air-conditioned spaces play an important role to attain comfort and hygiene conditions. This paper utilizes a 3D Computational Fluid Dynamics (CFD) model to assess the airflow characteristics in ventilated and air-conditioned archaeological Church of Christ (hanging Church) in Cairo, Egypt. It is found that the optimum airside design system can be attained, if the airflow is directed to pass all the enclosure areas before the extraction with careful selection of near wall velocities to avoid any wear or aberration of the wall paintings. Still all commonly known factors and evaluation indices have the shortage to describe the influence of the recirculation zones on the occupancy zone of the visitors and also on the fresh supplied air. The mode of evaluation should assess the airflow characteristics in any passage according to its position in the enclosure and the thermal pattern and air quality. The paper ends with brief discussion and concluding remarks.

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