Numerical Simulation of Heat and Fluid Flow in a Basic Pulse-Tube Refrigerator

2004 ◽  
Author(s):  
Takao Koshimizu ◽  
Hiromi Kubota ◽  
Yasuyuki Takata ◽  
Takehiro Ito
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Heat Exchange ◽  
Surface Heat ◽  
Physical Models ◽  
The Other ◽  
Pulse Tube ◽  
Working Principle ◽  
Pulse Tube Refrigerators ◽  
Heat And Fluid Flow

The working principle of refrigeration in basic pulse-tube refrigerators (BPTR) has been explained by the mechanism called surface heat pumping (SHP) that heat is conveyed from the cold end to the hot end of the pulse tube by the successive heat exchange between the working gas and the wall. In this study, a numerical simulation has been performed to clarify the effect of the wall in BPTRs by comparing the numerical results in two physical models; one is the model considering the heat exchange between the working gas and the wall (HE model), and the other is the model ignoring that (AW model). As a result, the importance in the effect of the wall was shown clearly. In addition, the mechanism of refrigeration other than the SHP was made clear in the AW model.

Numerical Simulation of Heat Pumping in a Pulse Tube Refrigerator

2007 ◽  
Author(s):  
Takao Koshimizu ◽  
Hiromi Kubota ◽  
Yasuyuki Takata ◽  
Takehiro Ito
Keyword(s):  
Numerical Simulation ◽  
Pulse Tube ◽  
Pulse Tube Refrigerator ◽  
Heat Quantity ◽  
The Difference ◽  
Regenerator Material ◽  
Energy Equations ◽  
Pulse Tube Refrigerators ◽  
Heat And Fluid Flow ◽  
Heat Pumping

Numerical simulation of heat and fluid flow in a basic and an orifice pulse tube refrigerator have been performed to visualize heat pumping generated in the regenerator and the pulse tube, and to clarify the difference in heat pumping caused by the phase difference between pressure and displacement of gas. Common components of the regenerator and the pulse tube are used in the basic and the orifice pulse tube refrigerator. The flow in the tube is assumed to be one-dimensional and compressible. As governing equations, the continuity, momentum and energy equations are used in this study. From the temperature and velocity field obtained as a result of the simulation, the relation between the displacement and the temperature change of gas elements is visually clarified, and consequently it is found that the characteristic that the temperatures of gas elements are nearly higher than those of the regenerator material or the pulse-tube wall during compression and lower during expansion is very important for the heat pumping in basic and orifice pulse tube refrigerators. Furthermore, the behavior of heat pumping in the basic and the orifice pulse tube refrigerator is illustrated by analyzing the relation between the displacement of gas elements and heat quantity transferred to the wall from the gas elements, and the difference in heat pumping between the basic and the orifice pulse tube refrigerator is made clear.

scholarly journals Numerical Simulation of Heat and Fluid Flow in Basic Pulse Tube Refrigerator

2003 ◽  
Vol 2003.7 (0) ◽  
pp. 99-100
Author(s):  
Takao KOSHIMIZU ◽  
Hiromi KUBOTA ◽  
Yasuyuki TAKATA ◽  
Takehiro ITO
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Pulse Tube ◽  
Pulse Tube Refrigerator ◽  
Heat And Fluid Flow

D05 Numerical Simulation of Heat and Fluid Flow in Pulse Tube Refrigerator

2001 ◽  
Vol 2001.5 (0) ◽  
pp. 125-128
Author(s):  
Takao KOSHIMIZU ◽  
Hiromi KUBOTA ◽  
Yasuyuki TAKATA ◽  
Takehiro ITO
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Pulse Tube ◽  
Pulse Tube Refrigerator ◽  
Heat And Fluid Flow

711 Numerical Simulation of heat and fluid flow in oil-immersed transformer

2008 ◽  
Vol 2008.45 (0) ◽  
pp. 237-238
Author(s):  
Takahiro SAKAKIBARA ◽  
Masaru ISHIZUKA ◽  
Shinji NAKAGAWA
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Heat And Fluid Flow

CFD-Based Study of Velocity and Temperature Distribution among Rib-Tube in Heat Environment

2014 ◽  
Vol 487 ◽  
pp. 558-561
Author(s):  
Su Hou De ◽  
Zhang Yu Fu ◽  
Che Ji Yong ◽  
Wu Shi Lei ◽  
Xiao Long Wen
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Heat Exchange ◽  
Temperature Distribution ◽  
Velocity Distribution ◽  
Engineering Application ◽  
Dispersed Phase ◽  
Wall Function ◽  
Governing Equations ◽  
Theory Analysis

The velocity distribution coupled thermal and fluid flow a rib-tube was studied in this article. Based on theory analysis and numerical simulation, we choose modal and wall function to simulate the flow in rib-tube, velocity to definite the dispersed phase. The governing equations were built and solved by numerical way. The progress of flow and heat exchange in rib-tube, the rules and contours of temperature, velocity were obtained, they shows that, along the rib-tube, velocity was changed with the temperature rising , which could give us a reference for engineering application .

Numerical Simulation of Twin-Parachute Inflation Process for Aircraft Ejection Escape

2020 ◽  
Author(s):  
Liwu Wang ◽  
Mingzhang Tang ◽  
Sijun Zhang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Model ◽  
Physical Models ◽  
The Other ◽  
Arbitrary Lagrangian Eulerian ◽  
Safe Distance ◽  
Structure Interaction ◽  
Parachute Inflation ◽  
Good Agreement

Abstract In order to study the safe distance between twin-parachute during their inflation process for fighter ejection escape, the fighter was equipped with two canopies and two seats, two types of parachute were used to numerically simulate their inflation process, respectively. One of them is C-9, the other a slot-parachute (S-P). Their physical models were built, then the meshes inside and around both parachutes were generated for fluid-structure interaction (FSI) simulation. The penalty function and the arbitrary Lagrangian-Eulerian (ALE) method were employed in the FSI simulation. To validate the numerical model for FSI simulation, at first the single parachute of the twin-parachute was used for the FSI simulation, the predicted inflation times for both types of parachute were compared with the experimental data. The computed results are in good agreement with experimental data. As a result, the inflation times were predicted with twin-parachute for both kinds of parachute. On the basis of the locations of ejected seats after the separation of seat and pilot, the initial locations and orientations of twin-parachute were also obtained. The numerical simulations for both kinds of parachute were performed by the FSI method, respectively. Our results illustrate that when the interval time for two seats ejected is greater than 0.25s, two pilots attached the twin-parachute are safe, and the twin-parachute would not interfere each other. Moreover, our results also indicate that the FSI simulation for twin-parachute inflation process is feasible for engineering applications and have a great potential for wide use.

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