Some gas dynamic relations for real gas flows in the presence of heat transfer

1990 ◽  
Vol 33 (2) ◽  
pp. 225-228 ◽  
Author(s):  
E.A. Orudzhaliyev
Keyword(s):  
Heat Transfer ◽  
Gas Flows ◽  
Real Gas ◽  
Gas Dynamic ◽  
Dynamic Relations

scholarly journals Thermal-mechanical characteristics of stationary and pulsating gas flows in a gas-dynamic system (in relation to the exhaust system of an engine)

2021 ◽  
pp. 171-171
Author(s):  
Leonid Plotnikov
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Dynamic System ◽  
Transfer Coefficient ◽  
Local Heat Transfer ◽  
Stationary Flow ◽  
Local Heat ◽  
Gas Flows ◽  
Gas Dynamic ◽  
The Heat Transfer Coefficient

It is a relevant objective in thermal physics and in building reciprocating internal combustion engines (RICE) to obtain new information about the thermal-mechanical characteristics of both stationary and pulsating gas flows in a complex gas-dynamic system. The article discusses the physical features of the gas dynamics and heat transfer of flows along the length of a gas-dynamic system typical for RICE exhaust systems. Both an experimental set-up and experimental techniques are described. An indirect method for determining the local heat transfer coefficient of gas flows in pipelines with a constant temperature hot-wire anemometer is proposed. The regularities of changes in the instantaneous values of the flow rate and the local heat transfer coefficient in time for stationary and pulsating gas flows in different elements of the gas-dynamic system are obtained. The regularities of the change in the turbulence number of stationary and pulsating gas flows along the length of RICE gas-dynamic systems are established (it is shown that the turbulence number for a pulsating gas flow is 1.3-2.1 times higher than for a stationary flow). The regularities of changes in the heat transfer coefficient along the length of the engine?s gas-dynamic system for stationary and pulsating gas flows were identified (it was established that the heat transfer coefficient for a stationary flow is 1.05-1.4 times higher than for a pulsating flow). Empirical equations are obtained to determine the turbulence number and heat transfer coefficient along the length of the gas-dynamic system.

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.

The interaction of a shock wave with a laminar boundary layer at a compression corner in high-enthalpy flows including real gas effects

1997 ◽  
Vol 342 ◽  
pp. 1-35 ◽  
Author(s):  
S. G. MALLINSON ◽  
S. L. GAI ◽  
N. R. MUDFORD
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Shock Wave ◽  
Gas Flows ◽  
Perfect Gas ◽  
Experimental Conditions ◽  
Real Gas ◽  
High Enthalpy ◽  
Compression Corner ◽  
Real Gas Effects

The high-enthalpy, hypersonic flow over a compression corner has been examined experimentally and theoretically. Surface static pressure and heat transfer distributions, along with some flow visualization data, were obtained in a free-piston shock tunnel operating at enthalpies ranging from 3 MJ kg−1 to 19 MJ kg−1, with the Mach number varying from 7.5 to 9.0 and the Reynolds number based on upstream fetch from 2.7×104 to 2.7×105. The flow was laminar throughout. The experimental data compared well with theories valid for perfect gas flow and with other relevant low-to-moderate enthalpy data, suggesting that for the current experimental conditions, the real gas effects on shock wave/boundary layer interaction are negligible. The flat-plate similarity theory has been extended to include equilibrium real gas effects. While this theory is not applicable to the current experimental conditions, it has been employed here to determine the potential maximum effect of real gas behaviour. For the flat plate, only small differences between perfect gas and equilibrium gas flows are predicted, consistent with experimental observations. For the compression corner, a more rapid rise to the maximum pressure and heat transfer on the ramp face is predicted in the real gas flows, with the pressure lying slightly below, and the heat transfer slightly above, the perfect gas prediction. The increase in peak heat transfer is attributed to the reduction in boundary layer displacement thickness due to real gas effects.

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

An Evaluation of Roe's Scheme Generalizations for Equilibrium Real Gas Flows

1997 ◽  
Vol 138 (2) ◽  
pp. 354-399 ◽  
Author(s):  
Lorenzo Mottura ◽  
Luigi Vigevano ◽  
Marco Zaccanti
Keyword(s):  
Gas Flows ◽  
Real Gas

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.

Thermal and mechanical improvement of the air supply system of a turbocharged piston engine

2021 ◽  
Vol 14 (2) ◽  
pp. 108-114
Author(s):  
Y. M. Brodov ◽  
L. V. Plotnikov ◽  
K. O. Desyatov
Keyword(s):  
Heat Transfer ◽  
Experimental Studies ◽  
Local Heat Transfer ◽  
Supply System ◽  
Scale Model ◽  
Piston Engine ◽  
Intake System ◽  
Gas Dynamic ◽  
Air Supply ◽  
Air Flows

A method of thermomechanical improvement of pulsating air flows in the intake system of a turbocharged piston engine is described. The main objective of this study is to develop a method for suppressing the rate of heat transfer to improve the reliability of a piston turbocharged engine. A brief review of the literature on improving the reliability of piston engines is given. Scientific and technical results were obtained on the basis of experimental studies on a full-scale model of a piston engine. The hot-wire anemometer method was used to obtain gas-dynamic and heatexchange characteristics of gas flows. Laboratory stands and instrumentation facilities are described in the article. The data on gas dynamics and heat exchange of stationary and pulsating air flows in gas-dynamic systems of various configurations as applied to the air supply system of a turbocharged piston engine are presented. A method of thermomechanical improvement of flows in the intake system of an engine based on a honeycomb is proposed in order to stabilize the pulsating flow and suppress the intensity of heat transfer. Data were obtained on the air flow rate and the local heat transfer coefficient both in the exhaust duct of the turbocharger compressor (i.e., without a piston engine) and in the intake system of a supercharged engine. A comparative analysis of the data has been carried out. It was found that the installation of a leveling grid in the exhaust channel of a turbocharger leads to an intensification of heat transfer by an average of 9%. It was found that the presence of a leveling grid in the intake system of a piston engine causes the suppression of heat transfer within 15% in comparison with the baseline values. It is shown that the use of a modernized intake system in a diesel engine increases its probability of failure-free operation by 0.8%. The data obtained can be extended to other types and designs of air supply systems for heat engines.

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