Implementation and evaluation of air flow and heat transfer routines for building simulation tools

Dissertation

Research output: ThesisDissertationCollection of Articles

Abstract

Environmental, epidemiological and economical reasons increase the pressure to design, construct and maintain better buildings in the future. Therefore, a new assembly of simulation routines for predicting both ventilation and heat transfer processes of buildings were studied. The work was limited to implementation and evaluation of new air flow and heat transfer routines for building simulation tools. Development of simulation tool user-interfaces, post-processors and component database have all been excluded. The simulation routines were implemented in a new building simulation tool BUS++, which was based on discretisation and solution of mass, momentum, and heat balance equations. Ventilation fans, external wind and thermal buoyancy were included as driving forces for air infiltration and ventilation process. Two completely new routines were developed and implemented to obtain more reliable estimations of dynamic and multi-mode heat transfer covering thermal convection, conduction, and radiation. The first new routine focused on defining a rational thermal calculation network, and the second one concentrated on simulation of thermal radiation in a room. Finally, a rigorous set of tests were conducted to validate the air flow and heat transfer routines implemented in BUS++. The test set included commonly utilised analytical verifications and inter-model comparisons as well as completely new empirical validation test cases. The new rational gridding method reduced simulation times by 44 % to 86 % in a typical slab test case with a cyclic excitation, and the new routine for thermal radiation was up to ten times faster than the conventional matrix radiosity method. In addition, the simulation and validation data showed good agreement, especially for the analytical verifications and inter-model comparisons with typical differences less than 2 %. Despite these promising results, more research work is needed to further develop the simulation routines. In the future, special attention ought to be paid to simulation tool user-interfaces to facilitate full utilisation of the simulation tool by a wide range of users.
Original languageEnglish
QualificationDoctor Degree
Awarding Institution
  • Aalto University
Award date23 Aug 2002
Place of PublicationEspoo
Publisher
Print ISBNs951-38-5995-9
Electronic ISBNs951-38-5996-7
Publication statusPublished - 2002
MoE publication typeG5 Doctoral dissertation (article)

Fingerprint

Heat transfer
Ventilation
Air
Heat radiation
User interfaces
Buoyancy
Infiltration
Fans
Program processors
Momentum
Radiation
Hot Temperature

Keywords

  • air conditioning
  • HVAC systems
  • heat transfer
  • air flow
  • air quality
  • buildings
  • simulation
  • BUS++
  • networks
  • data processing

Cite this

@phdthesis{60ef7cf085cc4548960865aee5b03e5e,
title = "Implementation and evaluation of air flow and heat transfer routines for building simulation tools: Dissertation",
abstract = "Environmental, epidemiological and economical reasons increase the pressure to design, construct and maintain better buildings in the future. Therefore, a new assembly of simulation routines for predicting both ventilation and heat transfer processes of buildings were studied. The work was limited to implementation and evaluation of new air flow and heat transfer routines for building simulation tools. Development of simulation tool user-interfaces, post-processors and component database have all been excluded. The simulation routines were implemented in a new building simulation tool BUS++, which was based on discretisation and solution of mass, momentum, and heat balance equations. Ventilation fans, external wind and thermal buoyancy were included as driving forces for air infiltration and ventilation process. Two completely new routines were developed and implemented to obtain more reliable estimations of dynamic and multi-mode heat transfer covering thermal convection, conduction, and radiation. The first new routine focused on defining a rational thermal calculation network, and the second one concentrated on simulation of thermal radiation in a room. Finally, a rigorous set of tests were conducted to validate the air flow and heat transfer routines implemented in BUS++. The test set included commonly utilised analytical verifications and inter-model comparisons as well as completely new empirical validation test cases. The new rational gridding method reduced simulation times by 44 {\%} to 86 {\%} in a typical slab test case with a cyclic excitation, and the new routine for thermal radiation was up to ten times faster than the conventional matrix radiosity method. In addition, the simulation and validation data showed good agreement, especially for the analytical verifications and inter-model comparisons with typical differences less than 2 {\%}. Despite these promising results, more research work is needed to further develop the simulation routines. In the future, special attention ought to be paid to simulation tool user-interfaces to facilitate full utilisation of the simulation tool by a wide range of users.",
keywords = "air conditioning, HVAC systems, heat transfer, air flow, air quality, buildings, simulation, BUS++, networks, data processing",
author = "Pekka Tuomaala",
year = "2002",
language = "English",
isbn = "951-38-5995-9",
series = "VTT Publications",
publisher = "VTT Technical Research Centre of Finland",
number = "471",
address = "Finland",
school = "Aalto University",

}

Implementation and evaluation of air flow and heat transfer routines for building simulation tools : Dissertation. / Tuomaala, Pekka.

Espoo : VTT Technical Research Centre of Finland, 2002. 50 p.

Research output: ThesisDissertationCollection of Articles

TY - THES

T1 - Implementation and evaluation of air flow and heat transfer routines for building simulation tools

T2 - Dissertation

AU - Tuomaala, Pekka

PY - 2002

Y1 - 2002

N2 - Environmental, epidemiological and economical reasons increase the pressure to design, construct and maintain better buildings in the future. Therefore, a new assembly of simulation routines for predicting both ventilation and heat transfer processes of buildings were studied. The work was limited to implementation and evaluation of new air flow and heat transfer routines for building simulation tools. Development of simulation tool user-interfaces, post-processors and component database have all been excluded. The simulation routines were implemented in a new building simulation tool BUS++, which was based on discretisation and solution of mass, momentum, and heat balance equations. Ventilation fans, external wind and thermal buoyancy were included as driving forces for air infiltration and ventilation process. Two completely new routines were developed and implemented to obtain more reliable estimations of dynamic and multi-mode heat transfer covering thermal convection, conduction, and radiation. The first new routine focused on defining a rational thermal calculation network, and the second one concentrated on simulation of thermal radiation in a room. Finally, a rigorous set of tests were conducted to validate the air flow and heat transfer routines implemented in BUS++. The test set included commonly utilised analytical verifications and inter-model comparisons as well as completely new empirical validation test cases. The new rational gridding method reduced simulation times by 44 % to 86 % in a typical slab test case with a cyclic excitation, and the new routine for thermal radiation was up to ten times faster than the conventional matrix radiosity method. In addition, the simulation and validation data showed good agreement, especially for the analytical verifications and inter-model comparisons with typical differences less than 2 %. Despite these promising results, more research work is needed to further develop the simulation routines. In the future, special attention ought to be paid to simulation tool user-interfaces to facilitate full utilisation of the simulation tool by a wide range of users.

AB - Environmental, epidemiological and economical reasons increase the pressure to design, construct and maintain better buildings in the future. Therefore, a new assembly of simulation routines for predicting both ventilation and heat transfer processes of buildings were studied. The work was limited to implementation and evaluation of new air flow and heat transfer routines for building simulation tools. Development of simulation tool user-interfaces, post-processors and component database have all been excluded. The simulation routines were implemented in a new building simulation tool BUS++, which was based on discretisation and solution of mass, momentum, and heat balance equations. Ventilation fans, external wind and thermal buoyancy were included as driving forces for air infiltration and ventilation process. Two completely new routines were developed and implemented to obtain more reliable estimations of dynamic and multi-mode heat transfer covering thermal convection, conduction, and radiation. The first new routine focused on defining a rational thermal calculation network, and the second one concentrated on simulation of thermal radiation in a room. Finally, a rigorous set of tests were conducted to validate the air flow and heat transfer routines implemented in BUS++. The test set included commonly utilised analytical verifications and inter-model comparisons as well as completely new empirical validation test cases. The new rational gridding method reduced simulation times by 44 % to 86 % in a typical slab test case with a cyclic excitation, and the new routine for thermal radiation was up to ten times faster than the conventional matrix radiosity method. In addition, the simulation and validation data showed good agreement, especially for the analytical verifications and inter-model comparisons with typical differences less than 2 %. Despite these promising results, more research work is needed to further develop the simulation routines. In the future, special attention ought to be paid to simulation tool user-interfaces to facilitate full utilisation of the simulation tool by a wide range of users.

KW - air conditioning

KW - HVAC systems

KW - heat transfer

KW - air flow

KW - air quality

KW - buildings

KW - simulation

KW - BUS++

KW - networks

KW - data processing

M3 - Dissertation

SN - 951-38-5995-9

T3 - VTT Publications

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -