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Full-Text Articles in Engineering

To Increasing The Absorption Area Of Column Apparatus With Tubular Lattice Nozzles, Nurmukhamedov Habibulla Sagdullaevich, Batir Babatulaev, Elbek Mavlanov, Samukdjan Nigmadjanov Mar 2021

To Increasing The Absorption Area Of Column Apparatus With Tubular Lattice Nozzles, Nurmukhamedov Habibulla Sagdullaevich, Batir Babatulaev, Elbek Mavlanov, Samukdjan Nigmadjanov

Chemical Technology, Control and Management

The problem of creating a compact refrigeration zone for absorbers with tubular-lattice nozzles made of pipes with spiral turbulators is discussed. Research has been carried out on the influence of the groove depth h/D and α/αгл of the step of their placement t/D on the degree of heat transfer intensification α/αо in the transition region of the gas-liquid flow. An intensification of heat transfer has been achieved only by increasing the groove depth from h/D = 0,003 to 0,095 and the optimal pitch of the grooves, the intensity of heat transfer is 2 or more times. Research has …


Developing Highly Efficient Industrial Contact Heat Exchanger, Khoshim Shayimovich Bakhronov, Abdumalik Abduvahobovich Akhmatov, Yorkin Bakhodirovich Kadirov Jul 2020

Developing Highly Efficient Industrial Contact Heat Exchanger, Khoshim Shayimovich Bakhronov, Abdumalik Abduvahobovich Akhmatov, Yorkin Bakhodirovich Kadirov

Chemical Technology, Control and Management

The paper presents the results of an experimental study of the intensification of heat transfer of a swirling flow in a cylindrical channel with two tangential and axial swirlers. During the experiments, such parameters were measured as: air flow in front of the vortex apparatus; hot water consumption; pressure drop in the vortex apparatus; temperature of working media at the inlet to the apparatus and at the outlet of it. A method for intensifying the heat transfer process, which is based on swirling a gas stream by its tangential supply, has been developed and investigated. Experimental studies of the intensity …


Critical Radius Of Insulation, Maria N. Ambrose, Samuel J. Sayre, Travis W. Martin, Matt T. Sterling Dec 2019

Critical Radius Of Insulation, Maria N. Ambrose, Samuel J. Sayre, Travis W. Martin, Matt T. Sterling

Mechanical Engineering

The critical radius of insulation is a counterintuitive concept within the study of heat transfer. The theory states that adding insulation to a cylindrical or spherical object will increase the rate of heat loss rather than decrease it, if the radius (thickness) of the insulation is at its “critical” value. The Critical Radius of Insulation Senior Project is designed to demonstrate this phenomenon to Heat Transfer students via a portable apparatus. The concept will be demonstrated with a cylindrical object which is heated by way of a separate voltage source. Thermocouples will display the temperature of the cylinder while insulation …


Radiation And Convective Losses In The Heat Sink Channel Of Photovoltaic-Thermal System, Oskar F. Tukhfatullin, Ramizulla A. Muminov Jun 2019

Radiation And Convective Losses In The Heat Sink Channel Of Photovoltaic-Thermal System, Oskar F. Tukhfatullin, Ramizulla A. Muminov

Euroasian Journal of Semiconductors Science and Engineering

. The processes of heat transfer in the channel of a liquid photovoltaic/thermal system of a flat construction without forced circulation are considered. A method of calculating the heat transfer coefficients by radiation and convection, the Nusselt and Reynolds numbers for a given photovoltaic/thermal system was proposed. It was determined that the processes of convective heat transfer in a flat photovoltaic/thermal system installed in the territory of the Republic of Uzbekistan at an optimum angle of inclination equal to the geographical latitude of the place of operation should be considered as for parallel plates located at tilt angle not more …


Radiation And Convective Losses In The Heat Sink Channel Of Photovoltaic-Thermal System, Oskar F. Tukhfatullin, Ramizulla A. Muminov Jun 2019

Radiation And Convective Losses In The Heat Sink Channel Of Photovoltaic-Thermal System, Oskar F. Tukhfatullin, Ramizulla A. Muminov

Euroasian Journal of Semiconductors Science and Engineering

. The processes of heat transfer in the channel of a liquid photovoltaic/thermal system of a flat construction without forced circulation are considered. A method of calculating the heat transfer coefficients by radiation and convection, the Nusselt and Reynolds numbers for a given photovoltaic/thermal system was proposed. It was determined that the processes of convective heat transfer in a flat photovoltaic/thermal system installed in the territory of the Republic of Uzbekistan at an optimum angle of inclination equal to the geographical latitude of the place of operation should be considered as for parallel plates located at tilt angle not more …


Thermal Characterization Of Magnetic Components, Jiazhou Zhong, Veda Samhitha Duppalli, Scott D. Sudhoff Professor Aug 2017

Thermal Characterization Of Magnetic Components, Jiazhou Zhong, Veda Samhitha Duppalli, Scott D. Sudhoff Professor

The Summer Undergraduate Research Fellowship (SURF) Symposium

Thermal limits are crucial constraints in the design of power magnetic components. As the power density of magnetic components continues to increase, cooling becomes more critical. Our research focuses on solving for the amount of cooling needed for a particular magnetic component. During the research process, a low-velocity wind tunnel designed and built from the ground up is used to form uniform and controlled conditions for the test components. Thermal Equivalent Circuit (TEC) and parameter identification techniques are used in conjunction to yield temperature distribution results. The expected result is temperature data on various areas of the component under different …


Enhancement Of Performance Parameters Of Transformer Using Nanofluids, Innovative Research Publications Irp India, Raja Sekhar Dondapati, Vishnu Saini, Niraj Kishore, Vicky V Jun 2015

Enhancement Of Performance Parameters Of Transformer Using Nanofluids, Innovative Research Publications Irp India, Raja Sekhar Dondapati, Vishnu Saini, Niraj Kishore, Vicky V

Innovative Research Publications IRP India

Transformer is a soul of both transmission and distribution systems. It performs low voltage to high voltage conversion in transmission lines and similarly high voltage to low voltage conversion in distribution lines. The operation of transformer is decided by the cooling provided to the system. The efficient cooling method is achieved by the use of forced (or) natural oil cooling medium. The oils used for the purpose of coolants are the hydrocarbons of paraffin (or) naphtha based petroleum products. The oil is used as coolant is made from highly refined mineral oil and it has high dielectric strength. During the …


Design, Manufacturing, And Assembly Of A Flexible Thermoelectric Device, Christopher Anthony Martinez Jan 2013

Design, Manufacturing, And Assembly Of A Flexible Thermoelectric Device, Christopher Anthony Martinez

USF Tampa Graduate Theses and Dissertations

This thesis documents the design, manufacturing, and assembly of a flexible thermoelectric device. Such a device has immediate use in haptics, medical, and athletic applications. The governing theory behind the device is explained and a one dimensional heat transfer model is developed to estimate performance. This model and consideration for the manufacturing and assembly possibilities are the drivers behind the decisions made in design choices. Once the design was finalized, manufacturing methods for the various components were explored. The system was created by etching copper patterns on a copper/polyimide laminate and screen printing solder paste onto the circuits. Thermoelectric elements …


Coupled Electromagnetic And Heat Transfer Model For Microwave Heating In Domestic Ovens, Krishnamoorthy Pitchai, Sohan Birla, Jeyamkondan Subbiah, D. D. Jones, Harshanardhan Thippareddi Jan 2012

Coupled Electromagnetic And Heat Transfer Model For Microwave Heating In Domestic Ovens, Krishnamoorthy Pitchai, Sohan Birla, Jeyamkondan Subbiah, D. D. Jones, Harshanardhan Thippareddi

Department of Food Science and Technology: Faculty Publications

Microwave ovens are used extensively for heating a variety of not-ready-to-eat food products. Non-uniform heating of foods in microwave ovens is a major concern in assuring microbiological safety of such products. The non-uniform heating of foods is attributed by complex interaction of microwaves with foods. To understand this complex interaction, a comprehensive model was developed to solve coupled electromagnetic and heat transfer equations using finite-difference time-domain based commercial software. The simulation parameters, cell size, heating time step, and number of iterations for steady state electromagnetic field were optimized. The model was validated by 30 s heating profile of a cylindrical …


Transferts De Chaleur Dans Un Réacteur Thermochimique Solaire Muni D’Un Récepteur Volumique Poreux, Hernando Romero Paredes Rubio May 2011

Transferts De Chaleur Dans Un Réacteur Thermochimique Solaire Muni D’Un Récepteur Volumique Poreux, Hernando Romero Paredes Rubio

Hernando Romero Paredes Rubio

Un réacteur thermochimique solaire de 1 kW muni d’une structure céramique poreuse en céramique est modélisé pour simuler les transferts thermiques a l’intérieur du récepteur volumétrique. Le modèle développé a été utilisé pour prévoir le comportement thermique du réacteur en fonction des différentes conditions opératoires qui concernent le débit de gaz inerte, le flux solaire incident, la porosité, la longueur du récepteur, et la prise en compte de réactions chimiques. Les résultats montrent que la température maximale est de 1850K pour une concentration solaire de 1000 soleils. La température diminue de manière significative lorsque le débit de gaz augmente. Un …


Online Tuning Of Set-Point Regulator With A Blending Mechanism Using Pi Controller, Engi̇n Yeşi̇l, Müjde Güzelkaya, İbrahi̇m Eksi̇n, Ö. Aydin Teki̇n Jan 2008

Online Tuning Of Set-Point Regulator With A Blending Mechanism Using Pi Controller, Engi̇n Yeşi̇l, Müjde Güzelkaya, İbrahi̇m Eksi̇n, Ö. Aydin Teki̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new control structure that exploits the advantages of one degree of freedom (1-DOF) and two degree of freedom (2-DOF) control structures with an online tuned set-point regulator with blending mechanism (SPR-BM) is proposed. In this structure, the filtered output of the reference and the pure reference signals are blended so that the overall performance of the system is ameliorated with respect to load disturbance rejection and set-point following. Internal Model Control (IMC) based PI controller is used as the primary controller and the blending dynamics are determined with the aim of producing a system output that …


Reflection High-Energy Electron-Diffraction Study Of Melting And Solidification Of Pb On Graphite, Z. H. Zhang, P. Kulatunga, H. E. Elsayed-Ali Jan 1997

Reflection High-Energy Electron-Diffraction Study Of Melting And Solidification Of Pb On Graphite, Z. H. Zhang, P. Kulatunga, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The melting and solidification of Pb thin films on pyrolytic graphite are investigated in situ by reflection high-energy electron diffraction. Thin films with thicknesses of 4-150 monolayers are investigated. The surface morphology of the thin films were studied by scanning electron microscopy. Superheating of the Pb thin films by 4±2 to 12±2 K is observed from diffraction intensity measurements. Upon cooling the substrate, the Pb on graphite is seen to supercool by ∼69±4 K.