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Article
Publication date: 1 December 2006

Qiuwang Wang, Feng Wu, Min Zeng, Laiqin Luo and Jiguo Sun

To find the optimal number of channels of rocket engine thrust chamber, it was found that the optimal channel number is 335, at which the cooling effect of the thrust chamber…

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Abstract

Purpose

To find the optimal number of channels of rocket engine thrust chamber, it was found that the optimal channel number is 335, at which the cooling effect of the thrust chamber cooling channel reaches the best, which can be helpful to design rocket engine thrust chamber.

Design/methodology/approach

The commercial computational fluid dynamics (CFD) software FLUENT with standard kε turbulent model was used. The CFD method was validated via comparing with the available experimental data.

Findings

It was found that both the highest temperature and the maximal heat flux through the wall on the hot‐gas side occurs about the throat region at the symmetrical center of the cooling channel. Owing to the strong curvature of the cooling channel geometry, the secondary flow reached its strongest level around the throat region. The typical values of pressure drop and temperature difference between the inlet and exit of cooling channel were 2.7 MPa and 67.38 K (standard case), respectively. Besides an optimal number of channels exist, and it is approximately 335, which can make the effect of heat transfer of cooling channels best with acceptable pressure drop. As a whole, the present study gives some useful information to the thermal design of liquid rocket engine thrust chamber.

Research limitations/implications

More detailed computation and optimization should be performed for the fluid flow and heat transfer of cooling channel.

Practical implications

A very useful optimization on heat transfer and fluid flow in cooling channel of liquid rocket engine thrust chamber.

Originality/value

This paper provides the performance of optimization on heat transfer and fluid flow in cooling channel of liquid rocket engine thrust chamber, which can make the effect of heat transfer of cooling channels best with acceptable pressure drop. As a whole, the present study gives some useful information to the thermal design of liquid rocket engine thrust chamber.

Details

Engineering Computations, vol. 23 no. 8
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 19 July 2019

Peyman Maghsoudi, Sadegh Sadeghi, Qingang Xiong and Saiied Mostafa Aminossadati

Because of the appreciable application of heat recovery systems for the increment of overall efficiency of micro gas turbines, promising evaluation and optimization are crucial…

175

Abstract

Purpose

Because of the appreciable application of heat recovery systems for the increment of overall efficiency of micro gas turbines, promising evaluation and optimization are crucial. This paper aims to propose a multi-factor theoretical methodology for analysis, optimization and comparison of potential plate-fin recuperators incorporated into micro gas turbines. Energetic, exergetic, economic and environmental factors are covered.

Design/methodology/approach

To demonstrate applicability and reliability of the methodology, detailed thermo-hydraulic analysis, sensitivity analysis and optimization are conducted on the recuperators with louver and offset-strip fins using a genetic algorithm. To assess the relationship between investment cost and profit for the recuperated systems, payback period (PBP), which incorporates all the factors is used as the universal objective function. To compare the performance of the recuperated and non-recuperated systems, exergy efficiency, exergy destruction and corresponding cost rate, fuel consumption and environmental damage cost rates, capital and operational cost rates and acquired profit rates are determined.

Findings

Based on the results, optimal PBP of the louvered-fin recuperator (147 days) is slightly lower than that with offset-strip fins (153 days). The highest profit rate is acquired by reduction of exergy destruction cost rate and corresponding decrements for louver and offset-strip fins are 2.3 and 3.9 times compared to simple cycle, respectively.

Originality/value

This mathematical study, for the first time, focuses on introducing a reliable methodology, which covers energetic, exergetic, economic and environmental points of view beneficial for design and selection of efficient plate-fin recuperators for micro gas turbine applications.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 31 January 2022

You Wang, Tingting Ma and Jialin Ren

The purpose of this paper is to explore the variation law between the clay microstructure and macro external force by using soil scanning electron microscope (SEM) images.

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Abstract

Purpose

The purpose of this paper is to explore the variation law between the clay microstructure and macro external force by using soil scanning electron microscope (SEM) images.

Design/methodology/approach

First, SEM images of clay were pre-processed by MATLAB, and quantitative statistical parameters such as directional probability entropy, fractal dimension and shape factor are extracted. Second, the distribution force model was proposed, considering that the microscopic parameters of soil particles were independent of each other, and the distribution coefficient was determined according to the analytic hierarchy process (AHP). Then, the fitted formula of quantitative statistical parameters based on the distribution force model was obtained by taking the macroscopic distribution force as independent variable and the microscopic parameters of soil particles as dependent variable. Finally, the correctness of corresponding fitting formula was verified.

Findings

The results showed that the change of external consolidation pressure has great influence on the directional probability entropy and fractal dimension, while the shape factor reflecting the regular degree of soil particle shape is less sensitive to the consolidation pressure. The fitting formula has high accuracy, and mostly the R value can reach more than 0.9. All the data have passed the test, which proves that the distribution force model proposed in this paper is rational.

Originality/value

The model can be used to connect the macroscopic stress of soil with the micro-structure deformation of soil particles through mathematical formula, which can provide reference for engineering practice.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

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Article
Publication date: 28 June 2023

Ahmed Youcef, Rachid Saim and Hakan F. Öztop

The purpose of this paper is to give a comparison between different type of baffles for a better application. Computational analysis of heat transfer and fluid flow through plain…

160

Abstract

Purpose

The purpose of this paper is to give a comparison between different type of baffles for a better application. Computational analysis of heat transfer and fluid flow through plain, flower and perforated baffles for heat exchanger.

Design/methodology/approach

Numerical simulations for heat exchangers with plain, flower and perforated baffles are carried out with finite volume method. The thermal-hydraulic performance for the three types is presented in the same conditions.

Findings

The perforated baffles generate low shell pressure with high Nusselt number; transverse baffles give the best heat transfer with high pumping power. The overall performance coefficient of these three types of heat exchangers shows that the perforated baffles have a highest and the transverse baffles have the lowest. Analysis of the results show that perforated transverse baffles produce pressure drop lower by 6.68% than transverse baffles and 2.64% lower than flower baffles. The pumping power for perforated transverse baffles lower by 13.3% to the transverse baffles and 4.72% lower than that of flower baffles. The Nusselt number for perforated baffles higher by 4.16% to the flower baffles and 2.77% with transverse baffles. The overall performance factor in the heat exchanger with perforated baffles higher by 5.55% to that with transverse baffles and 3.46% with flower baffles. Recirculation areas are reduced in shell with perforated baffles and velocity distribution becomes more uniform.

Originality/value

Using of perforated baffles in heat exchanger give the best overall performance factor.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 9
Type: Research Article
ISSN: 0961-5539

Keywords

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