Measurement and Three-Dimensional Computational Analysis for Flow Electrification in Complex-Shaped Ducts

2016 ◽  
Vol 136 (3) ◽  
pp. 318-324
Author(s):  
Naoya Miyamoto ◽  
Makoto Koizumi ◽  
Hiroshi Miyao ◽  
Takayuki Kobayashi ◽  
Kojiro Aoki
2013 ◽  
Vol 19 (2) ◽  
pp. 021102 ◽  
Author(s):  
Shang Wang ◽  
Chih-Hao Liu ◽  
Valery P. Zakharov ◽  
Alexander J. Lazar ◽  
Raphael E. Pollock ◽  
...  

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ömer Akbal ◽  
Hakan F. Öztop ◽  
Nidal H. Abu-Hamdeh

Purpose The purpose of this paper is to make a three-dimensional computational analysis of melting in corrugated pipe inserted system filled with phase change material (PCM). The system was heated from the inner pipe, and temperature of the outer pipe was lower than that of inner pipe. Different geometrical ratio cases and two different temperature differences were tested for their effect on melting time. Design/methodology/approach A computational analysis through a pipe with corrugated pipe filled with PCM is analyzed. Finite volume method was applied with the SIMPLE algorithm method to solve the governing equations. Findings The results indicate that the geometrical parameters can be used to control the melting time inside the heat exchanger which, in turn, affect the energy efficiency. The fastest melting time is seen in Case 4 at the same temperature difference which is the major observation of the current work. Originality/value Originality of this work is to perform a three-dimensional analysis of melting of PCM in a corrugated pipe inserted pipe.


Author(s):  
Alka Gupta ◽  
Mohamed Saeed Ibrahim ◽  
R. S. Amano

This paper presents the computational analysis of the dilution process involved in gas turbines order to cool the combustion gases to the desired temperature before it enters the turbine. Here, it should be noted that in order to focus only on the dilution process, non-reacting flow conditions were simulated and the complete system was reduced to mixing of a primary (hot) stream and dilution (cold) stream of air. Four different schemes were investigated based on the layout of the dilution holes and use of a blunt body. A complete three dimensional analysis was carried out for each case in order to investigate its effectiveness to produce a more uniform temperature conditions at the exit of the combustor, so as to reduce the detrimental effect these temperature non-uniformities have on the turbine blades. For comparison of the proposed schemes, a parameter is defined in terms of the temperatures of the dilution and primary flow streams at the inlet and the exit plane, called the mixture fraction. Based on this parameter, it was found that the staggered dilution holes with the blunt body has the mixture fraction closest to the equilibrium mixture fraction (0.4), which implies that this scheme with the mixture fraction of 0.36, resulted in best mixing and produced the most uniform temperature distribution at the exit amongst the four proposed schemes.


2005 ◽  
Author(s):  
Khaled Alhussan ◽  
Charles Garris

The work to be presented herein is a Computational Fluid Dynamics investigation of the complex fluid mechanisms that occur inside a non-steady, three-dimensional, supersonic pressure exchange ejector, specifically with regard to the pressure exchange mechanisms and the induction processes between a “driving” primary fluid and a “driven” secondary fluid and how this is affected by the diffuser surface. The results will show that this ejector is capable of producing the desire affect of the flow induction in a three-dimensional supersonic, non-steady, viscous flow. Results of contour plots of total pressure and static pressure demonstrate that the flow inside the diffuser is a critical element in flow induction mechanism, especially when a pressure recovery is needed. Results of velocity vectors will show the structure of flow induction mechanism in a complex three-dimensional conical surface.


1969 ◽  
Vol 73 (697) ◽  
pp. 55-65 ◽  
Author(s):  
J. H. Argyris ◽  
D. W. Scharpf

It is by now well established that the computational analysis of significant problems in structural and continuum mechanics by the matrix displacement method often requires elements of higher sophistication than used in the past. This refers, in particular, to regions of steep stress gradients, which are frequently associated with marked changes in geometry, involving rapid variations of the radius of curvature. The philosophy underlying the idealisation of such configurations into finite elements was discussed in broad terms in ref. 1. It was emphasised that the so successful, constant strain, two-dimensional TRIM 3 and three-dimensional TET 4 elements do not, in general, prove the best choice. For this reason elements with a linear variation of strain like TRIM 6 and TET 10 were originally evolved and followed up with the quadratic strain elements TRIM 15, TRIA 4 (two-dimensional) and TET 20, TEA 8 (three-dimensional) of ref. 2. However, all these elements are characterised by straight edges and necessitate a polygonisation or polyhedrisation in the idealisation process. This may not be critical in many problems, but is sometimes of doubtful validity in the immediate neighbourhood of a curved boundary, where stress concentrations are most pronounced. To overcome this difficulty with a significant (local) increase of elements does not always yield the most economical and technically satisfactory solution. Moreover, there arises another inevitable shortcoming when dealing with TRIM and TET elements with a linear or quadratic variation of strain. Indeed, while TRIM 3 and TET 4 elements permit a very elegant extension into the realm of large displacements, this is not possible for the higher order TRIM and TET elements. This is simply due to the fact that TRIM 3 and TET 4 elements, by virtue of their specification, always remain straight under any magnitude of strain, but this is not so for the triangular and tetrahedron elements of higher sophistication.


2020 ◽  
Vol 26 (6) ◽  
pp. 465-474
Author(s):  
Deepak Singh ◽  
Dhananjay Singh ◽  
Sattar Husain

This research article reports the computational analysis of temperature distribution in microwave-heated convenience food such as potato. The detailed study of temperature (because temperature is a function of bacterial inactivation) and microwave powers along with drying time for the preservation of food material has been presented. Therefore, a mathematical model for potato sample is developed to predict the behavior of temperature distribution at each possible point and different shapes (slab, cylindrical, and spherical) of food material. The developed mathematical model is programmed by MATLAB software. Another parameter, microwave power is also a function of temperature. The ranging values of various microwave powers (125 W, 375 W, 625 W, 875 W, and 1250 W) along with different values of drying time (0 to 10 minutes) have been used for computation. The obtained results show the uniformity of temperature distribution throughout the whole product in the form of a three-dimensional structure. The model provides the minimum and maximum temperature ranges in specimens without performing an experiment which depicts the condition of bacterial inactivation.


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