Appendix gap losses in Stirling engines – review of recent findings

The appendix gap loss in Stirling cycle machines is generated by the annular gap around the thermally insulating, thin-walled dome typically attached to a piston or displacer plunging into the hot cylinder volume of an engine or the cold volume of a cryocooler. It was considered to be of minor impor...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Kühl Hans-Detlev, Sauer Jan
Formato:	article
Lenguaje:	EN FR
Publicado:	EDP Sciences 2021
Materias:	Environmental sciences GE1-350
Acceso en línea:	https://doaj.org/article/8462dabe615d406e9cc82f96b6624063
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:8462dabe615d406e9cc82f96b6624063
record_format	dspace
spelling	oai:doaj.org-article:8462dabe615d406e9cc82f96b66240632021-11-08T15:18:57ZAppendix gap losses in Stirling engines – review of recent findings2267-124210.1051/e3sconf/202131303001https://doaj.org/article/8462dabe615d406e9cc82f96b66240632021-01-01T00:00:00Zhttps://www.e3s-conferences.org/articles/e3sconf/pdf/2021/89/e3sconf_isec2021_03001.pdfhttps://doaj.org/toc/2267-1242The appendix gap loss in Stirling cycle machines is generated by the annular gap around the thermally insulating, thin-walled dome typically attached to a piston or displacer plunging into the hot cylinder volume of an engine or the cold volume of a cryocooler. It was considered to be of minor importance for decades. Thus, simplified analytical models were considered sufficiently accurate for its description, until numerical simulations and experimental results gave rise to a more detailed analysis revealing that, neglecting entrance and end effects, the flow is typically laminar, but unsteady. Subsequently, an enhanced analytical model accounting for fluidic and thermal inertia effects as well as the volumetric displacement by the seal was developed. Compared to the previous ones, this model predicts a shift of the optimum width to smaller values, a higher minimum overall loss and furthermore, an option to decrease the loss by reducing the effective seal diameter. This could be experimentally confirmed as well as the unsteady gas temperature profiles predicted by this model. Subsequently, both theoretically and experimentally founded correlations for the radial and axial energy transport in the gap were derived and implemented in a differential simulation of the gap within a third order code.Kühl Hans-DetlevSauer JanEDP SciencesarticleEnvironmental sciencesGE1-350ENFRE3S Web of Conferences, Vol 313, p 03001 (2021)
institution	DOAJ
collection	DOAJ
language	EN FR
topic	Environmental sciences GE1-350
spellingShingle	Environmental sciences GE1-350 Kühl Hans-Detlev Sauer Jan Appendix gap losses in Stirling engines – review of recent findings
description	The appendix gap loss in Stirling cycle machines is generated by the annular gap around the thermally insulating, thin-walled dome typically attached to a piston or displacer plunging into the hot cylinder volume of an engine or the cold volume of a cryocooler. It was considered to be of minor importance for decades. Thus, simplified analytical models were considered sufficiently accurate for its description, until numerical simulations and experimental results gave rise to a more detailed analysis revealing that, neglecting entrance and end effects, the flow is typically laminar, but unsteady. Subsequently, an enhanced analytical model accounting for fluidic and thermal inertia effects as well as the volumetric displacement by the seal was developed. Compared to the previous ones, this model predicts a shift of the optimum width to smaller values, a higher minimum overall loss and furthermore, an option to decrease the loss by reducing the effective seal diameter. This could be experimentally confirmed as well as the unsteady gas temperature profiles predicted by this model. Subsequently, both theoretically and experimentally founded correlations for the radial and axial energy transport in the gap were derived and implemented in a differential simulation of the gap within a third order code.
format	article
author	Kühl Hans-Detlev Sauer Jan
author_facet	Kühl Hans-Detlev Sauer Jan
author_sort	Kühl Hans-Detlev
title	Appendix gap losses in Stirling engines – review of recent findings
title_short	Appendix gap losses in Stirling engines – review of recent findings
title_full	Appendix gap losses in Stirling engines – review of recent findings
title_fullStr	Appendix gap losses in Stirling engines – review of recent findings
title_full_unstemmed	Appendix gap losses in Stirling engines – review of recent findings
title_sort	appendix gap losses in stirling engines – review of recent findings
publisher	EDP Sciences
publishDate	2021
url	https://doaj.org/article/8462dabe615d406e9cc82f96b6624063
work_keys_str_mv	AT kuhlhansdetlev appendixgaplossesinstirlingenginesreviewofrecentfindings AT sauerjan appendixgaplossesinstirlingenginesreviewofrecentfindings
_version_	1718441967915892736

Appendix gap losses in Stirling engines – review of recent findings

Ejemplares similares