Research Article
Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle
Kum Song Choe,
Yong Jae Min*
,
Sang Dok Ri,
Myong Chol Ri
Issue:
Volume 11, Issue 3, September 2025
Pages:
33-49
Received:
1 July 2025
Accepted:
22 July 2025
Published:
25 August 2025
Abstract: Since the effects of various irreversible losses and cycle conditions on the internal combustion engine performance are significant, it is important to compare the effects of the parameters on the performance in a cycle study. Thermodynamic cycle studies should take into account the irreversible losses such as internal irreversibility, friction losses, heat transfer losses, and the variation of the specific heat of the working fluid. This study aims at deriving the analytic equation with respect to ecological function of the irreversible Dual-Miller cycle (DMC) by using the specific heat model of polynomial, and comparing results of performance calculation of different friction losses, and analyzing the effect of the cycle parameters for optimum performance. The calculation results show that the friction loss has a considerable influence on the engine performance, but there is no significant difference in the choice of the cycle parameters for optimum performance. It is also found that optimizing the ecological function is an effective way to simultaneously increase the power and efficiency, and the friction loss is not affected. The cut-off ratio, which gives the ecological function maximum, is between the cut-off ratio, which gives the power and efficiency maximum, and the Miller cycle ratio, respectively, which is closer to the efficiency maximum. The Miller cycle ratio that maximizes performance is slightly larger than the cut-off ratio. The presented models and results are expected to provide guidelines for the design and optimization of DMC engines, and for the performance improvement and to perform the cycle modeling close to the cycle of the actual engine.
Abstract: Since the effects of various irreversible losses and cycle conditions on the internal combustion engine performance are significant, it is important to compare the effects of the parameters on the performance in a cycle study. Thermodynamic cycle studies should take into account the irreversible losses such as internal irreversibility, friction los...
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Research Article
Heat-generating Obstacle of Nanofluid Flow in a Rhombus-shaped Enclosure Filled with Porous Media
Md. Rasel Rana Khandaker,
Md. Jahirul Haque Munshi*,
Md. Mahmud Alam
Issue:
Volume 11, Issue 3, September 2025
Pages:
50-61
Received:
11 March 2025
Accepted:
22 May 2025
Published:
29 August 2025
Abstract: The main goal of the current research is to investigate the flow of an innovative nanofluid technology with a heat-generating obstruction in a rhombus-shaped the enclosure that the is filled with porous media. The current research addresses the implications of media with pores on the dimensionless Richardson and Darcy numbers for the heat-generating obstacle field. Numerical solutions to the problem have been found utilising the Galerkin weighted residual consider. The current study investigates the consequences of the Richardson and Darcy numbers on streamline equilibrium temperatures, devoid of dimension temperature, velocity characteristics, average fluid temperature, and Nusselt experiment numbers. The outcomes demonstrate that both components have significant implications on streamlines and equilibrium temperatures. Additionally, it is readily apparent that the Darcy number is a significant control parameter for heat transfer in fluid flow through the porous material that makes up an enclosure. A linear relationship for the average number obtained from Nusselt has been demonstrated according to various Darcy and Richardson principles. When there is an overwhelming concurrence amongst the results of the present investigation and previously published research, it has been validated.
Abstract: The main goal of the current research is to investigate the flow of an innovative nanofluid technology with a heat-generating obstruction in a rhombus-shaped the enclosure that the is filled with porous media. The current research addresses the implications of media with pores on the dimensionless Richardson and Darcy numbers for the heat-generatin...
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