THERMAL SCIENCE

International Scientific Journal

Umair Munir

,

Muhammad Sajid Kamran

,

Asad Naeem Shah

,

Muhammad Farhan

,

Zahid Anwar

THE CFD METHODOLOGY FOR SIMULATING PUMPING LOSS FROM DISPLACER AND PISTON SEALS OF FREE PISTON STIRLING ENGINE

ABSTRACT
A new axisymmetric CFD model capable of describing pumping loss is proposed for free piston Stirling engine. Inclusion of clearance seals, bounce space, heater, cooler, and regenerator in a single model is the unique strength of this work. For transient simulation of engine, dynamic mesh was utilized for catering needs of moving boundaries. The model was validated with 12.5 kW component test power converter and successfully predicted indicated power, efficiency, pressure amplitude, pressure drop, and gas temperature in expansion and compression space at different piston amplitudes with 6% maximum deviation. The results showed that the heat exchange at heater and cooler was minimized at each flow reversal and was strongly influenced by oscillating gas-flow rate. The results also present optimum displacer and piston seal clearance at different charge pressure and operating frequencies. The displacer seal clearance could be increased up to 125 μm without compromising power, however, engine output was severely affected with increasing piston seal gap.
KEYWORDS
Stirling engine, CFD, Clearance seal, Pumping loss, CTPC
PAPER SUBMITTED: 2020-04-08
PAPER REVISED: 2020-06-08
PAPER ACCEPTED: 2020-09-01
PUBLISHED ONLINE: 2020-10-10
DOI REFERENCE: https://doi.org/10.2298/TSCI200408295M
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2022, VOLUME 26, ISSUE Issue 1, PAGES [13 - 23]
REFERENCES
  1. Wang, K., et al., Stirling cycle engines for recovering low and moderate temperature heat: A review, Renewable and Sustainable Energy Reviews, 62. (2016), Supplement C, pp. 89-108, DOI No. doi.org/10.1016/j.rser.2016.04.031
  2. Shendage, D.J., et al., Numerical investigations on the Dish-Stirling engine system, International Journal of Ambient Energy, 40. (2019), 3, pp. 274-284, DOI No. 10.1080/01430750.2017.1388840
  3. Ribberink, H., et al., A plausible forecast of the energy and emissions performance of mature-technology Stirling engine residential cogeneration systems in Canada, Journal of Building Performance Simulation, 2. (2009), 1, pp. 47-61, DOI No. 10.1080/19401490802651925
  4. Bani-Hani, E., et al., Enhancing Cooling System of a Combustion Engine by Integrating with a Stirling Cycle, Energy Engineering, 116. (2019), 3, pp. 41-53, DOI No. 10.1080/01998595.2019.12057061
  5. Ahmadi, M.H., et al., Thermal models for analysis of performance of Stirling engine: A review, Renewable and Sustainable Energy Reviews, 68. (2017), pp. 168-184, DOI No. doi.org/10.1016/j.rser.2016.09.033
  6. Ye, W., et al., EXERGY LOSS ANALYSIS OF THE REGENERATOR IN A SOLAR STIRLING ENGINE, Thermal Science, 22. (2018),
  7. Sharma, A., et al., FINITE TIME THERMODYNAMIC ANALYSIS AND OPTIMIZATION OF SOLAR-DISH STIRLING HEAT ENGINE WITH REGENERATIVE LOSSES, Thermal Science, 15. (2011), 4
  8. Salazar, J.L.,W.-L. Chen, A computational fluid dynamics study on the heat transfer characteristics of the working cycle of a β-type Stirling engine, Energy Conversion and Management, 88. (2014), Supplement C, pp. 177-188, DOI No. doi.org/10.1016/j.enconman.2014.08.040
  9. Kato, Y., et al., Effect of geometry and speed on the temperatures estimated by CFD for an isothermal model of a gamma configuration low temperature differential Stirling engine with Flat-shaped heat exchangers, Applied Thermal Engineering, 115. (2017), Supplement C, pp. 111-122, DOI No. doi.org/10.1016/j.applthermaleng.2016.12.070
  10. Alfarawi, S., et al., Influence of phase angle and dead volume on gamma-type Stirling engine power using CFD simulation, Energy Conversion and Management, 124. (2016), Supplement C, pp. 130-140, DOI No. doi.org/10.1016/j.enconman.2016.07.016
  11. Li, Z., et al., Analysis of a high performance model Stirling engine with compact porous-sheets heat exchangers, Energy, 64. (2014), pp. 31-43
  12. Xiao, G., et al., Design optimization with computational fluid dynamic analysis of β-type Stirling engine, Applied Thermal Engineering, 113. (2017), Supplement C, pp. 87-102, DOI No. doi.org/10.1016/j.applthermaleng.2016.10.063
  13. Kuban, L., et al., A 3D-CFD study of a γ-type Stirling engine, Energy, 169. (2019), pp. 142-159, DOI No. doi.org/10.1016/j.energy.2018.12.009
  14. Caetano, B.C., et al., A novel methodology on beta-type Stirling engine simulation using CFD, Energy Conversion and Management, 184. (2019), pp. 510-520, DOI No. doi.org/10.1016/j.enconman.2019.01.075
  15. Lewandowski, E.J.,P.K. Johnson, Stirling system modeling for space nuclear power systems. (2008),
  16. Dhar, M., Stirling Space Engine Program. Volume 1; Final Report. (1999),
  17. Tew, R., et al. An initial non-equilibrium porous-media model for CFD simulation of stirling regenerators,4th International Energy Conversion Engineering Conference and Exhibit (IECEC),2006, p. 4003
PDF VERSION [DOWNLOAD]
The CFD methodology for simulating pumping loss from displacer and piston seals of free piston Stirling engine

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence