Solution of Unsteady Fluid Dynamic and Energy Equations for High-Speed Oscillating Compressible Flows and Blast Wave Propagations

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ramlala P. Sinha
Keyword(s):  
Heat Transfer ◽  
Blast Wave ◽  
High Speed ◽  
Fluid Dynamic ◽  
Stable Solution ◽  
Heat Conducting ◽  
Arbitrary Boundary ◽  
One Dimensional ◽  
Unsteady Fluid ◽  
Energy Equations

Abstract A solution of the highly complex unsteady high-speed oscillating compressible flow field inside a cylindrical tube has been obtained numerically, assuming one-dimensional, viscous, and heat conducting flow, by solving the appropriate fluid dynamic and energy equations. The tube is approximated by a right circular cylinder closed at one end with a piston oscillating at very high resonant frequency at the other end. An iterative implicit finite difference scheme is employed to obtain the solution. The scheme permits arbitrary boundary conditions at the piston and the end wall and allows assumptions for transport properties. The solution would also be valid for tapered tubes if the variations in the cross-sectional area are small. In successfully predicting the time-dependent results, an innovative simple but stable solution of unsteady fluid dynamic and energy equations is provided here for wide-ranging research, design, development, analysis, and industrial applications in solving a variety of complex fluid flow heat transfer problems. The method is directly applicable to pulsed or pulsating flow and wave motion thermal energy transport, fluid–structure interaction heat transfer enhancement, and fluidic pyrotechnic initiation devices. It can further be easily extended to cover muzzle blasts and nuclear explosion blast wave propagations in one-dimensional and/or radial spherical coordinates with or without including energy generation/addition terms.

Time-Dependent Solution of Unsteady Fluid Flow Equations for High Speed Oscillating Compressible Flows and Blast Wave Propagations

2020 ◽  
Author(s):  
Ramlala P. Sinha
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Blast Wave ◽  
High Speed ◽  
Fluid Dynamic ◽  
Time Dependent ◽  
Arbitrary Boundary ◽  
One Dimensional ◽  
Unsteady Fluid ◽  
Energy Equations

Abstract A solution of the highly complex unsteady high speed oscillating compressible flow field inside a cylindrical tube has been obtained numerically, assuming one dimensional, viscous, and heat conducting flow, by solving the appropriate fluid dynamic and energy equations. The tube is approximated by a right circular cylinder closed at one end with a piston oscillating at very high resonant frequency at the other end. An iterative implicit finite difference scheme is employed to obtain the solution. The scheme permits arbitrary boundary conditions at the piston and the end wall and allows assumptions for transport properties. The solution would also be valid for tapered tubes if the variations in the cross-sectional area are small. In successfully predicting the time dependent results, an innovative simple but stable solution of unsteady fluid dynamic and energy equations is provided here for wide ranging research, design, development, analysis, and industrial applications in solving a variety of complex fluid flow heat transfer problems. The method is directly applicable to pulsed or pulsating flow and wave motion thermal energy transport, fluid-structure interaction heat transfer enhancement, and fluidic pyrotechnic initiation devices. It can further be easily extended to cover muzzle blasts and nuclear explosion blast wave propagations in one dimensional and/or radial spherical coordinates with or without including energy generation / addition terms.

Theoretical Analysis of Resonance Tube End Wall Heating: Solution of Unsteady Fluid Dynamic and Energy Equations

2015 ◽  
Author(s):  
Ramlala P. Sinha
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamic ◽  
Stable Solution ◽  
Heat Conducting ◽  
Cross Sectional ◽  
Arbitrary Boundary ◽  
Resonance Tube ◽  
Unsteady Fluid ◽  
Energy Equations ◽  
End Wall

A solution of the highly complex unsteady compressible flow field inside a cylindrical resonance tube has been obtained numerically, assuming one dimensional, viscous, and heat conducting flow, by solving the appropriate fluid dynamic and energy equations. The resonance tube is approximated by a right circular cylinder closed at one end with a piston oscillating at resonant frequency at the other end. An iterative implicit finite difference scheme is employed to obtain the solution. The scheme permits arbitrary boundary conditions at the piston and the end wall and allows assumptions for transport properties. For the example considered herein, the solution predicts a rise of 95°F in the mean end wall temperature, from 60°F to 155°F, in 14.313 milliseconds which is in good agreement with the experimentally observed values. The solution would also be valid for tapered tubes if the variations in the cross-sectional area are small. In successfully predicting the resonance tube results, an innovative simple but stable solution of unsteady fluid dynamic and energy equations is provided here for wide ranging research, development, and industrial applications in solving a variety of complex fluid flow heat transfer problems. The method is directly applicable to pulsed or pulsating flow and wave motion thermal energy transport, fluid-structure interaction heat transfer enhancement, and fluidic pyrotechnic initiation devices.

The Mechanics and Thermodynamics of Steady One-Dimensional Gas Flow

1947 ◽  
Vol 14 (4) ◽  
pp. A317-A336 ◽  
Author(s):  
Ascher H. Shapiro ◽  
W. R. Hawthorne
Keyword(s):  
Heat Transfer ◽  
Dimensional Analysis ◽  
High Speed ◽  
Gas Flow ◽  
Gas Injection ◽  
Wall Friction ◽  
Analytical Treatment ◽  
Area Change ◽  
One Dimensional ◽  
Recent Developments

Abstract Recent developments in the fields of propulsion, flow machinery, and high-speed flight have emphasized the need for an improved understanding of the characteristics of compressible flow. A one-dimensional analysis for flow without shocks is presented which takes into account the simultaneous effects of area change, wall friction, drag of internal bodies, external heat exchange, chemical reaction, change of phase, injection of gases, and changes in molecular weight and specific heat. The method of selecting independent and dependent variables, and the organization of the working equations, leads, it is believed, to a better understanding of the influence of the foregoing effects, and also simplifies greatly the analytical treatment of particular problems. Examples are given first of several simple types of flow, including (a) area change only; (b) heat transfer only; (c) wall friction only; and (d) gas injection only. In addition, examples of flow with combined effects are given, including (a) simultaneous friction and area change; (b) simultaneous friction and heat transfer; and (c) simultaneous liquid injection and evaporation. A one-dimensional analysis for flow through a discontinuity is presented, allowing for energy, shock, drag, and gas-injection effects, and for changes in gas properties. This analysis is applicable to such processes as: (a) the adiabatic normal shock; (b) combustion; (c) moisture condensation shocks; and (d) steady explosion waves.

scholarly journals Filtration of Liquid in a Non-isothermal Viscous Porous Medium

2020 ◽  
pp. 763-773
Author(s):  
Alexander A. Papin ◽  
Margarita A. Tokareva ◽  
Rudolf A. Virts
Keyword(s):  
Porous Medium ◽  
Boundary Value Problem ◽  
Fluid Motion ◽  
Initial Boundary ◽  
Initial Boundary Value Problem ◽  
Heat Conducting ◽  
System Of Equations ◽  
One Dimensional ◽  
Unsteady Fluid ◽  
Initial Boundary Value

The solvability of the initial-boundary value problem is proved for the system of equations of one-dimensional unsteady fluid motion in a heat-conducting viscous porous medium

MotoGP 2007: Criteria for Engine Optimization

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Enrico Mattarelli
Keyword(s):  
High Speed ◽  
Fluid Dynamic ◽  
Weight Ratio ◽  
Engine Performance ◽  
Real Data ◽  
Mechanical Efficiency ◽  
Point Of View ◽  
One Dimensional ◽  
Four Cylinders ◽  
Technical Regulations

The paper proposes some design criteria for the MotoGP engines, complying with the FIM 2007 Technical Regulations. Five configurations have been considered: engines with three cylinders in line and four cylinders in line, and three V engines with four, five, and six cylinders. All the analyzed solutions have been optimized from a fluid-dynamic point of view by means of one dimensional engine cycle simulations. Then, the engines are compared in terms of full load performance at steady conditions. Finally, the influence of engine performance, along with operation regularity and motorbike weight, is assessed by means of a lap time simulator, developed by the author on the base of real data. The best configurations turned out to be the four-cylinder engines, while three-cylinder and five-cylinder engines are quite penalizing. The key of the four-cylinder engines success is their good breathing capability and mechanical efficiency at high speed, yielding an optimum power-to-weight ratio, associated with a good engine regularity, i.e., a smooth response to throttle angle variations.

Modeling a high-speed pin-on-disk experiment

2021 ◽  
pp. 154851292110403
Author(s):  
Aron Wing ◽  
Tony Liu ◽  
Anthony Palazotto
Keyword(s):  
Heat Transfer ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Spectral Methods ◽  
High Speed ◽  
Moving Boundary ◽  
Frictional Heat ◽  
Element Analysis ◽  
One Dimensional ◽  
Pin On Disk

The purpose of this work is to analyze the heat transfer characteristics of Vascomax®C300 during high-speed sliding. This work extends previous research that is intended to help predict the wear-rate of connecting shoes for a hypersonic rail system at Holloman Air Force Base to prevent critical failure of the system. Solutions were generated using finite element analysis and spectral methods. The frictional heat generated by the pin-on-disk is assumed to flow uniformly and normal to the face of the pin and the pin is assumed to be a perfect cylinder resulting in two-dimensional heat flow. Displacement data obtained from the experiment is used to define the moving boundary. The distribution of temperature resulting from transient finite element analysis is used to justify a one-dimensional model. Spectral methods are then employed to calculate the spatial derivatives improving the approximation of the function which represents the data. It is concluded that a one-dimensional approach with constant heat transfer parameters sufficiently models the high-speed pin-on-disk experiment.

Unsteady Heat Transfer in Baffled Channels

1996 ◽  
Vol 118 (3) ◽  
pp. 585-591 ◽  
Author(s):  
G. Wang ◽  
K. Stone ◽  
S. P. Vanka
Keyword(s):  
Heat Transfer ◽  
Critical Reynolds Number ◽  
Reynolds Numbers ◽  
Process Industry ◽  
Unsteady Heat Transfer ◽  
Enhancement Of Heat Transfer ◽  
Compact Heat Exchangers ◽  
Unsteady Fluid Flow ◽  
Unsteady Fluid ◽  
Energy Equations

In this paper, the enhancement of heat transfer due to unsteady flow in channels with in-line and staggered baffles is investigated through the numerical solution of the governing unsteady fluid flow and energy equations with periodicity in the stream wise direction. For the inline configuration, the flow becomes naturally unsteady at a critical Reynolds number (Q/v) around 110. For the staggered case, this value is around 200. Significant increases in heat transfer rate are observed once the flow becomes unsteady. Results for several Reynolds numbers up to 500 are presented. The present results can be valuable to the design and operation of compact heat exchangers used in process industry.

Numerical Heat Transfer and Fluid Flow Modeling of a Nano-Robot Inside the Blood Stream of an Aorta

2007 ◽  
Author(s):  
M. Ghassemi ◽  
M. Varmarzyar ◽  
M. K. Ebrahimi ◽  
M. Zare
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamic ◽  
Nonlinear Partial Differential Equations ◽  
Blood Stream ◽  
Nano Technology ◽  
Medical Treatments ◽  
Numerical Heat Transfer ◽  
Promising Area ◽  
Energy Equations ◽  
Fluid Flow Modeling

The idea of nano-technology started in 1959. It has been used in different applications since its creation. One of its new areas of applications is in medicine. From medical instruments (i.e. sensors etc) to medical treatments nano-technology is playing a major role. Application of nano-robot inside human blood for health purposes is a promising area. The purpose of this study is to investigate the flow field and heat transfer modeling of a nano-robot inside the biggest human vein, Aorta. In our formulation of governing nonlinear partial differential equations, momentum and energy equations are applied to the blood and the nano-robot. The equations are solved by a computational fluid dynamic code. The velocity profile, pressure and temperature distribution of the nano-robot in direction of the blood stream as well as in opposite direction of the blood stream are calculated. Results are verified with a known experimental condition. Results show that the nano-robot does not disturb the blood stream significantly. Therefore it is safe to use such devices inside blood stream for medical purposes.

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