Numerical and experimental studies of heat transfer in particle-laden gas flows through a vertical riser

2012 ◽  
Vol 33 (1) ◽  
pp. 118-130 ◽  
Author(s):  
Samy M. El-Behery ◽  
W.A. El-Askary ◽  
Mofreh H. Hamed ◽  
K.A. Ibrahim
Keyword(s):  
Heat Transfer ◽  
Experimental Studies ◽  
Gas Flows

scholarly journals Heat transfer intensity of pulsating gas flows in the exhaust system elements of a piston engine

2019 ◽  
Vol 124 ◽  
pp. 01015
Author(s):  
L. V. Plotnikov ◽  
Y. M. Brodov ◽  
M. O. Misnik
Keyword(s):  
Heat Transfer ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Exhaust System ◽  
Scale Model ◽  
Gas Flows ◽  
Exhaust Pipe ◽  
Piston Engine ◽  
Gas Dynamic ◽  
Valve Assembly

Internal combustion engines are the most common sources of energy among heat engines. Therefore, the improvement of their design and workflow is an urgent task in the development of world energy. Thermal-mechanical perfection of the exhaust system has a significant impact on the technical and economic performance of piston engines. The article presents the results of experimental studies of gas-dynamics and heat exchange of pulsating gas flows in the exhaust system of a piston engine. Studies were carried out on a full-scale model of a single-cylinder engine. The article describes the instrument-measuring base and methods of experiments. The heat transfer intensity was estimated in different elements of the exhaust system: the exhaust pipe, the channel in the cylinder head, the valve assembly. Heat transfer studies were carried out taking into account the gas-dynamic nonstationarity characteristic of gas exchange processes in engines. The article presents data on the influence of gas-dynamic and regime factors on the heat transfer intensity. It is shown that the restructuring of the gas flow structure in the exhaust system occurs depending on the engine crankshaft speed, this has a significant impact on the local heat transfer coefficient. It has been established that the heat transfer intensity in the valve assembly is 2-3 times lower than in other elements of the exhaust system.

scholarly journals Numerical and physical modeling of heat transfer in the exhaust system of a piston engine in stationary conditions

2019 ◽  
Vol 196 ◽  
pp. 00006
Author(s):  
Leonid Plotnikov ◽  
Alexandr Nevolin ◽  
Mariya Misnik
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Experimental Studies ◽  
Exhaust System ◽  
Gas Flows ◽  
Hydraulic Systems ◽  
Stationary Conditions ◽  
Ice Leads ◽  
Numerical Simulation Technique ◽  
Exhaust Systems

Thermomechanical perfection of exhaust systems largely determines the efficiency of the engine boost system. The article presents the results of numerical simulation and experimental study of heat transfer of gas flows in profiled exhaust systems of ICE. The description of the numerical simulation technique, the experimental setup, the configurations of the hydraulic systems under investigation, the instrumentation and the experimental features are given in the article. On the basis of numerical simulation, it has been established that the use of profiled sections with a cross-section in the form of a square in the exhaust system of an ICE leads to a decrease in the heat transfer rate to 5 %. The use of profiled sections in the form of a triangle in the system under consideration causes a more significant decrease in heat transfer, which reaches 11 %. Experimental studies qualitatively confirm the results of simulation.

INVERSE PROBLEMS METHOD FOR STUDY OF HEAT TRANSFER IN SOLIDS INTERACTED WITH GAS FLOWS LOADED BY SOLID PARTICLES

Equipment ◽  
2006 ◽  
Author(s):  
Aleksey V. Nenarokomov ◽  
O. M. Alifanov ◽  
E. A. Artioukhine ◽  
I. V. Repin
Keyword(s):  
Heat Transfer ◽  
Inverse Problems ◽  
Solid Particles ◽  
Gas Flows

Method and tools for determining heat transfer coefficients in organic liquids and solutions

2020 ◽  
pp. 45-55
Author(s):  
Aleksandr S. MYAKOCHIN ◽  
Petr V. NIKITIN ◽  
Sergey Yu. POBEREZHSKIY ◽  
Anna A. SHKURATENKO
Keyword(s):  
Heat Transfer ◽  
Experimental Studies ◽  
Pulse Method ◽  
Organic Liquids ◽  
Transfer Coefficients ◽  
Resistance Thermometer ◽  
Film Sensor ◽  
Heat Transfer Coefficients ◽  
Aerospace Technology ◽  
New Generation

The paper presents a method, tools and a newly developed algorithm for experimentally determining heat transfer coefficients in organic liquids and solutions. This work is made relevant by the problem of development of a new generation of aerospace technology. In this connection, improvements have been made to the pulse method of determining heat transfer coefficients that is based on the use of a micron-thick film sensor. The measurement setup was modified. A math model was constructed for the measuring sensor. Algorithms were developed for conducting the experiment and processing measurement results to determine heat transfer coefficients. Experimental uncertainties were analyzed. The paper provides results of experimental studies on certain organic liquids. The authors believe that the material presented in the paper will find application in research conducted at research institutions, engineering offices and universities, among researches, postgraduates and students. Key words: thermal and physical characteristics, organic liquids and their solutions, film-type electrical resistor, thin-film temperature sensor, voltage pulse, resistance thermometer, irregular heat transfer regime.

Experimental studies on micro-channel heat sink with different heat transfer fluid

2021 ◽  
Author(s):  
M. P. Dhanishk ◽  
P. Selvakumar ◽  
V. Ashwin ◽  
P. N. ArunKumar
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Experimental Studies ◽  
Heat Transfer Fluid ◽  
Micro Channel

Numerical-Experimental Studies of the Heat Transfer in an Air-Cooled Condenser Model

2016 ◽  
Vol 50 (3) ◽  
pp. 318-322 ◽  
Author(s):  
V. A. Sukhanov ◽  
A. P. Bezukhov ◽  
I. A. Bogov ◽  
V. V. Tolmachev
Keyword(s):  
Heat Transfer ◽  
Experimental Studies

Influence of High-Frequency Gas-Dynamic Unsteadiness on Heat Transfer in Gas Flows of Internal Combustion Engines

2014 ◽  
Vol 698 ◽  
pp. 631-636 ◽  
Author(s):  
L.V. Plotnikov ◽  
B.P. Zhilkin ◽  
Y.M. Brodov
Keyword(s):  
Heat Transfer ◽  
High Frequency ◽  
Internal Combustion Engines ◽  
Rotation Angle ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Gas Flows ◽  
Combustion Engines ◽  
Instantaneous Values ◽  
Crankshaft Rotation

The results of experimental research of the influence of high-frequency gas-dynamical nonstationarity on the intensity of heat transfer in the intake and exhaust tract of piston engines are presented in the article. Experimental setup and methods of the experiments are described in the article. Dependences of instantaneous values of flow velocity and the local heat transfer coefficient in the intake and exhaust tract of the engine from the crankshaft rotation angle are presented in the article.

Possible Mechanisms for Thermal Conductivity Enhancement in Nanofluids

2006 ◽  
Author(s):  
Amit Gupta ◽  
Xuan Wu ◽  
Ranganathan Kumar
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Brownian Motion ◽  
Brownian Dynamics ◽  
Lattice Vibration ◽  
Experimental Studies ◽  
High Heat ◽  
Conductivity Enhancement ◽  
High Heat Transfer ◽  
Dynamics Simulations

This study discusses the merits of various physical mechanisms that are responsible for enhancing the heat transfer in nanofluids. Experimental studies have cemented the claim that ‘seeding’ liquids with nanoparticles can increase the thermal conductivity of the nanofluid by up to 40% for metallic and oxide nanoparticles dispersed in a base liquid. Experiments have also shown that the rise in conductivity of the nanofluid is highly dependent on the size and concentration of the nanoparticles. On the theoretical side, traditional models like Maxwell or Hamilton-Crosser models cannot explain this unusually high heat transfer. Several mechanisms have been postulated in the literature such as Brownian motion, thermal diffusion in nanoparticles and thermal interaction of nanoparticles with the surrounding fluid, the formation of an ordered liquid layer on the surface of the nanoparticle and microconvection. This study concentrates on 3 possible mechanisms: Brownian dynamics, microconvection and lattice vibration of nanoparticles in the fluid. By considering two nanofluids, copper particles dispersed in ethylene glycol, and silica in water, it is determined that translational Brownian motion of the nanoparticles, presence of an interparticle potential and the microconvection heat transfer are mechanisms that play only a smaller role in the enhancement of thermal conductivity. On the other hand, the lattice vibrations, determined by molecular dynamics simulations show a great deal of promise in increasing the thermal conductivity by as much as 23%. In a simplistic sense, the lattice vibration can be regarded as a means to simulate the phononic transport from solid to liquid at the interface.

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