Validation of hygrothermal material modelling under consideration of the hysteresis of moisture storage.

Gregor A. Scheffler

doi:10.51202/9783816796497

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Validation of hygrothermal material modelling under consideration of the hysteresis of moisture storage.

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Series:: Schriftenreihe / Publication Series - Technische Universität Dresden, Institut für Bauklimatik
Publisher:: 2016

Summary

The achievable accuracy of hygrothermal building component simulation is significantly dependent on the applied material functions. These functions are determined by the material modelling marking the connection between the basic storage and transport parameters which are obtained from basic measurements, and the storage and transport coefficients which are defined within the balance and flow equations. It is the aim of the present study to develop a flexible and widely applicable material model which is not restricted to the current level of the transport theory. Furthermore, limits and options of this model are to be validated by means of four building materials on the basis of special transient moisture profile measurements.

By the presented study, the material modelling has been decisively further developed, the set of basic measurement methods has been extended by a substantial experiment and the instantaneous profile measurement technique has been made applicable to Building Physics. Moreover, the influences of the process history and the process dynamics on the moisture transport and the resulting moisture profiles could be shown and proven. By that, not only a material model is now available which perfectly applies to the requirements of flexibility, applicability and extendibility. The obtained data provides also a powerful basis for further research and development.

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Bibliographic data

Copyright year: 2016
ISBN-Print: 978-3-8167-9648-0
ISBN-Online: 978-3-8167-9649-7
Publisher: Fraunhofer IRB Verlag, Stuttgart
Series: Schriftenreihe / Publication Series - Technische Universität Dresden, Institut für Bauklimatik
Language: English
Pages: 237
Product type: Book Titles

Titelei/Inhaltsverzeichnis Partial access Pages 1 - 12 Download chapter (PDF)
Introduction and Overview No access Pages 13 - 16
1. 1. Transport processes No access
  2. Balance equations of heat, air and moisture No access
  3. 1. Heat transport No access
    2. Air mass transport No access
    3. Moisture mass transport No access
  4. 1. The air mass balance No access
    2. Hygroscopic and overhygroscopic moisture range No access
    3. Moisture storage No access
    4. Hysteresis of moisture storage No access
2. 1. 1. Diffusivity approach according to Häupl No access
    2. Diffusivity approach according to Pel No access
    3. Diffusivity approach according to Kießl and Künzel No access
    4. Diffusivity approach according to Krus and Holm No access
    5. Diffusivity approach according to Carmeliet and Janssen No access
    6. Further diffusivity models No access
  2. 1. Simplified material models No access
    2. Network models No access
    3. Bundle of tubes models No access
3. Conclusions on material modelling No access
1. 1. Density and porosity No access
  2. Thermal properties No access
  3. Moisture storage No access
  4. Vapour diffusion No access
  5. Water uptake experiment No access
  6. Drying experiment No access
  7. Saturated and unsaturated flow experiments No access
  8. Concluding basic experimental methods No access
2. 1. Principle of instantaneous profile methods No access
  2. 1. Moisture content measurement No access
    2. Moisture potential measurement No access
  3. Concluding instantaneous profile measurements No access
3. Conclusions on Experimental Methods No access
Investigated Material No access Pages 83 - 86
1. 1. Moisture storage and pore structure No access
  2. 1. Moisture content regions No access
    2. Mechanistical approach: serial-parallel model No access
    3. Calibration of liquid and vapour transport coefficients No access
  3. Heat conduction No access
  4. Concluding the developments in material modelling No access
2. 1. 1. Vapour transfer - Influence of boundary conditions No access
    2. Moisture inside the material - Influence of transport properties No access
  2. 1. Influences and considerations No access
    2. Development of a drying apparatus No access
    3. Realisation of the drying apparatus No access
  3. 1. Attempts to standardize drying data No access
    2. Discussion on the proposed drying coefficient No access
    3. Concluding the drying coefficient No access
  4. Conclusions on the drying experiment No access
3. 1. Measurement set-up for the hygroscopic moisture range No access
  2. Measurement set-up for the overhygroscopic moisture range No access
  3. 1. TDR system configuration and calibration No access
    2. TDR data evaluation No access
  4. Conclusions on instantaneous profile measurements No access
4. Concluding Developments and Utilisation No access
1. 1. Program components No access
  2. Adjustment and calibration procedure No access
2. 1. Building brick No access
  2. Calcium silicate No access
  3. Aerated concrete No access
  4. Lime-sand brick No access
3. Implementation of TDR data evaluation No access
4. Application of the TDR models No access
5. Conclusions No access
1. 1. Transient moisture storage data No access
  2. Hygroscopic simulation results No access
  3. Concluding hygroscopic assessment No access
2. Overhygroscopic moisture transport No access
3. 1. Observation summary No access
  2. Discussion No access
  3. Concluding assessment No access
1. Content summary No access
2. Results and conclusions No access
3. Future prospects No access
List of Symbols and Abbreviations No access Pages 215 - 220
References No access Pages 221 - 237