On-site experimental estimation of thermal conductivities and heat capacities in multilayer walls under arbitrary transient conditions using explicit and implicit finite difference schemes

Antonopoulos, KA; Vrachopoulos, M

dc.contributor.author	Antonopoulos, KA	en
dc.contributor.author	Vrachopoulos, M	en
dc.date.accessioned	2014-03-01T01:12:10Z
dc.date.available	2014-03-01T01:12:10Z
dc.date.issued	1996	en
dc.identifier.issn	0363-907X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/11983
dc.subject	Heat capacity	en
dc.subject	Multilayer wall	en
dc.subject	Thermal conductivity	en
dc.subject	Transient	en
dc.subject.classification	Energy & Fuels	en
dc.subject.classification	Nuclear Science & Technology	en
dc.subject.other	Finite Difference Techniques	en
dc.subject.other	Multilayer	en
dc.subject.other	Thermal Conductivity	en
dc.subject.other	Walls	en
dc.subject.other	Finite difference method	en
dc.subject.other	Interpolation	en
dc.subject.other	Specific heat	en
dc.subject.other	Temperature measurement	en
dc.subject.other	Thermal conductivity	en
dc.subject.other	Transients	en
dc.subject.other	Walls (structural partitions)	en
dc.subject.other	Fourth order polynomial interpolation	en
dc.subject.other	Multilayer wall	en
dc.subject.other	Thermodynamic properties	en
dc.title	On-site experimental estimation of thermal conductivities and heat capacities in multilayer walls under arbitrary transient conditions using explicit and implicit finite difference schemes	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/(SICI)1099-114X(199601)20:1<17::AID-ER147>3.0.CO;2-5	en
heal.identifier.secondary	http://dx.doi.org/10.1002/(SICI)1099-114X(199601)20:1<17::AID-ER147>3.0.CO;2-5	en
heal.language	English	en
heal.publicationDate	1996	en
heal.abstract	It is often required to estimate the thermal properties of the layers of a multilayer wall, which is already part of an existing building. Such cases are encountered when an ex post check is required in order to find out if the design specifications have been followed, or if air conditioning loads have to be calculated in old buildings, the walls of which are composed of layers of unknown materials and thermal properties. In the present study, a method is proposed for estimating the thermal conductivities and heat capacities of the layers a multilayer wall is composed of. The method is based on explicit and implicit finite difference schemes and uses on-site temperature measurements at various locations within the wall. It is applicable to multilayer walls which are already parts of buildings. The outdoor and indoor conditions may be arbitrary, i.e. transient, nonperiodic, with solar radiation. The accuracy of the method, which has been verified by numerical and experimental applications, depends on the available number of temperature values in space. For example, in a 10-cm thick wall layer, measurement at five locations gives satisfactory accuracy, which is considerably improved by increasing the number of values in space using fourth-order polynomial interpolation.	en
heal.publisher	JOHN WILEY & SONS LTD	en
heal.journalName	International Journal of Energy Research	en
dc.identifier.doi	10.1002/(SICI)1099-114X(199601)20:1<17::AID-ER147>3.0.CO;2-5	en
dc.identifier.isi	ISI:A1996TQ21100002	en
dc.identifier.volume	20	en
dc.identifier.issue	1	en
dc.identifier.spage	17	en
dc.identifier.epage	32	en