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Article
Publication date: 1 April 1996

B.S.V.P. Patnaik, K.N. Seetharamu and P.A. Aswatha Narayana

A finite element method is used to study the effect of flow past acircular cylinder with an integral wake splitter. A fractional step algorithmis employed to solve the…

Abstract

A finite element method is used to study the effect of flow past a circular cylinder with an integral wake splitter. A fractional step algorithm is employed to solve the Navier‐Stokes and Energy equations with a Galerkin weighted residual formulation. The vortex shedding process is simulated and the effect of splitter addition on the time period of shedding is studied at a Reynolds number of 200 and a blockage ratio of 0.25. The effect of splitter and the Strouhal number and heat transfer augmentation per unit pressure drop has been investigated.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 6 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 9 August 2021

Vishnudas Alias Vipul Luvu Chodankar, Aswatha and K.N. Seetharamu

The purpose of this paper is to attain higher effectiveness with an introduction of Joule–Thomson effect on a three-fluid heat exchanger with two communications. It also gives a…

Abstract

Purpose

The purpose of this paper is to attain higher effectiveness with an introduction of Joule–Thomson effect on a three-fluid heat exchanger with two communications. It also gives a range of parameter values that have to be maintained for achieving effectiveness above 0.85. Attaining effectiveness above 0.85 is very important for the heat exchanger to perform the liquefaction of hot fluid.

Design/methodology/approach

The analysis is conducted using Galerkin’s method, a finite element approach.

Findings

This investigation determines crucial values for the cryogenic heat exchanger to achieve effectiveness above 0.85. The important findings are as follows: effectiveness above 0.85 is attained if the heat exchanger size is within the range of 8–10; ratio of heat flow resistance between intermediate and hot stream to heat flow resistance between cold and hot stream should be maintained between 1 and 10; the intermediate fluid temperature should be maintained between 0 and 0.2; the ratio of thermal capacity of the hot fluid relative to a cold fluid should be maintained between 1.25 and 1.42; and the ratio of thermal capacity of the hot fluid relative to an intermediate fluid should be maintained between 2 and 2.5.

Research limitations/implications

The investigation has presented a finding for improving the effectiveness of the cryogenic heat exchanger. Higher the Joule–Thomson pressure drop effect, more is the drop in temperature of the fluid resulting in additional cooling or lowering of the fluid temperature. The practical implementation is also explained, i.e. to achieve practically the Joule–Thomson pressure drop in a cryogenic heat exchanger.

Originality/value

To the best of the authors’ knowledge, no investigations were carried out previously on Joule–Thomson investigation on a three-fluid heat exchanger with two communications, for different values of Joule–Thomson pressure drop.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 November 2013

Thimmareddy G., Aswatha Reddy and Subrata Roy

This article attempts to study the influence of 1,2,3,4-Butane tetra carboxylic acid (BTCA)treatment on the properties of tassar silk fabric. Indian tassar (Anthrea mylitta D

Abstract

This article attempts to study the influence of 1,2,3,4-Butane tetra carboxylic acid (BTCA)treatment on the properties of tassar silk fabric. Indian tassar (Anthrea mylitta D) silk fabrics have been treated with BTCA, a non-formaldehyde cross-linking agent, in the presence of sodium hypophosphite monohydrate as the catalyst and non-ionic polyethylene emulsion as the softener. Fabric shrinkage (dimensional stability) in the warp and weft directions shows significant improvement after treatment and also, a 10% improvement in the fabric crease recovery is observed. Although the single yarn strength is not significantly affected, the elongation of yarn decreases by 15%. Similarly, the fabric tensile strength and air permeability properties are the least affected, but the fabric tearing strength significantly increases after treatment with BTCA. The treatment displays promising results for tassar fabrics, which are inherently susceptible to shrinkage issues.

Details

Research Journal of Textile and Apparel, vol. 17 no. 4
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 1 April 1993

B.V.K. SATYA SAI, K.N. SEETHARAMU, P.A. ASWATHA NARAYANA and J.N. REDDY

A finite element method based on the Eulerian velocity correction method has been used to analyse the laminar natural convection in an annular cavity. Unsteady, incompressible…

Abstract

A finite element method based on the Eulerian velocity correction method has been used to analyse the laminar natural convection in an annular cavity. Unsteady, incompressible, axisymmetric Navier‐Stokes equations have been made use of. Different radius ratios of the annular cavity have been considered to investigate the effect of the radius of curvature on the heat transfer coefficient.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 3 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Book part
Publication date: 1 November 2012

Satyadhyan Chickerur and Aswatha Kumar M

In this decade, educators in engineering higher education are at the cross roads. On one side there are people who argue that the traditional courses and teaching methods are…

Abstract

In this decade, educators in engineering higher education are at the cross roads. On one side there are people who argue that the traditional courses and teaching methods are still appropriate, while there are others who believe that the vast technological advancement in information and computing technologies could be harnessed for effective teaching and learning. This chapter presents an approach to develop industry-relevant curricula in engineering higher education that involves project-based learning. It is also shown that the effectiveness of the course can be improved by designing the curriculum using modified Bloom’s taxonomy and using various online tools and technologies. Discussion about various tools introduced and the rationale for using those tools is also covered. The impact of each tool on student learning is also summarized.

Details

Increasing Student Engagement and Retention Using Social Technologies
Type: Book
ISBN: 978-1-78190-239-4

Keywords

Article
Publication date: 1 January 2006

N. Aizar Abdul Karim, P.A. Aswatha Narayana and K.N. Seetharamu

To demonstrate thermal modeling technique for a through hole light emitting diode (LED) package using a commercial computational fluid dynamic (CFD) code and to improve its…

1464

Abstract

Purpose

To demonstrate thermal modeling technique for a through hole light emitting diode (LED) package using a commercial computational fluid dynamic (CFD) code and to improve its thermal performance through a series of sensitivity analyses.

Design/methodology/approach

Thermal resistance of the standard through hole LED is calculated using the simulation result. The result is then compared with actual measurement to establish the correct model. Using the validated model, series of sensitivity analyses are carried out through simulation. Taking the most optimum design, a prototype of the improved LED is fabricated and the thermal resistance performance is compared with the simulation result.

Findings

The simulation result of the standard LED is close to actual measurement with 5 percent difference. The thermal resistance of the through hole LED is reduced by changing the leadframe material from mild steel to copper alloy and increasing the leadframe width. Combination of both design changes resulted in thermal resistance reduction of 51 percent.

Originality/value

This paper identified the practicality of using CFD codes in achieving fast and accurate result in thermal modeling of LED package and also offers solutions on reducing the LED thermal resistance.

Details

Microelectronics International, vol. 23 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 February 1999

M.S. Rajagopal, K.N. Seetharamu and P.A. Aswatha Narayana

Accurate prediction of temperature distribution in an electrical machine at the design stage is becoming increasingly important. It is essential to know the locations and…

Abstract

Accurate prediction of temperature distribution in an electrical machine at the design stage is becoming increasingly important. It is essential to know the locations and magnitudes of hot spot temperatures for optimum design of electrical machines. A methodology based on axi‐symmetric finite element formulation has been developed to solve the conduction‐convection problem in radial cooled machines using a new eight noded solid‐fluid coupled element. The axi‐symmetric model adopted is formulated purely from dimensional data, property data and published convective correlations. Steady state temperatures have been determined for 102 kW radial cooled motor at 100 percent and 75 percent loads and are validated with experimental results obtained from heat run tests. Parametric studies have been carried out to study the effect of critical parameters on temperature distribution and for optimising the design.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 9 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Abstract

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 5
Type: Research Article
ISSN: 0961-5539

Content available
Book part
Publication date: 1 November 2012

Abstract

Details

Increasing Student Engagement and Retention Using Social Technologies
Type: Book
ISBN: 978-1-78190-239-4

Article
Publication date: 28 February 2023

Sivasankaran Sivanandam and Bhuvaneswari Marimuthu

The numerical analysis is to scrutinize the collective effect of convective current along with the thermal energy transport in an inclined lid-driven square chamber with sine…

Abstract

Purpose

The numerical analysis is to scrutinize the collective effect of convective current along with the thermal energy transport in an inclined lid-driven square chamber with sine curve based temperature at the lower wall in the existence of unchanging external magnetic field. Insulation has been placed on the left and right of the box to increase the effective space volume of the shell. The thermal condition at ceiling wall is kept lower than the one on the floor.

Design/methodology/approach

The finite volume method employs to discretize (non-dimensional) system of equations govern the model. The heat transfer rate is measured by adjusting various variables, such as the Richardson number Hartmann number, inclination of an enclosure.

Findings

The flow behavior of enclosure convection is more highly influenced within the natural convection when enclosure inclination varies as well as magnetic field strength. The overall heat transfer rate decreases due to increase in both the Hartmann number as well as Richardson number.

Practical implications

The results of the present study are very useful to the cooling of electronic equipments.

Social implications

The study model is useful to the thermal science community and modelling field.

Originality/value

This research is a novel work on mixed convection flow in an inclined chamber with sinusoidal heat source.

Details

Multidiscipline Modeling in Materials and Structures, vol. 19 no. 3
Type: Research Article
ISSN: 1573-6105

Keywords

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