Further developments in the conflation of CFD and building simulation

To provide practitioners with the means to tackle problems related to poor indoor environments, building simulation and computational fluid dynamics can usefully be integrated within a sin- gle computational framework. This paper describes the outcomes from a research project sponsored by the European Com- mission, which furthered the CFD modelling aspects of the ESP-r system. The paper sum- marises the form of the CFD model and describes the method used to integrate the thermal and flow domains.

 

Flow responsive modelling of internal surface convection

A flow responsive algorithm was devised and implemented within the ESP-r simulation program to advance the modelling of internal surface convection. Empirical methods were extracted from the lit- erature and a new method for characterizing mixed flow was created to provide the algorithm with a basis of 28 convection coefficient correlations. Col- lectively these methods can calculate convection coefficients for most flows of practical interest.

Experimental and numerical study of local mean age of air

This paper presents the results from the experimental and numerical study of a room with mixing ventilation, focused on the local mean age of air (LMA). The measurements were performed using the tracer gas concentration decay method.  The numerical predictions were obtained from the computational fluid dynamics (CFD) module of the latest version of the ESP-r software. In order to address the requirement for a proper choice of the number of control volumes in CFD, the analysis is made by comparing the results from two consequently finer numerical grids.

Estimation of relative humidity for thermal comfort assessment

Estimating  relative  humidity  from  outdoor  air temperature and humidity, and indoor air temperature is a means to assess thermal comfort conditions when indoor relative humidity is not available. Buildings in tropical countries are usually well ventilated in the summer and show a large infiltration area. Considering that sources of moisture are minimal in such cases, indoor absolute humidity can be assumed to be the same as the outdoor value.

Error estimation of measurement methods by computer simulation

Computer  simulation  Of  measurement  methods  can give in-depth information on the possible effect of a wide variety of parameters on measurement results. Examples for computer simulation of simple U-value measurements of building components for  the appraisal of retrofit measures and more complex examples of building airtightness measurements with the blower door method are given. The simulation models used are described in detail and results for example cases are given.

EnerXML: a schema for representing energy simulation data

The    eXtensible Markup Language (XML)  has recently become  the W3C  Standard      for commu nicating   data   over   the   Internet.      The   e- commerce    industry    and    several    new    software applications  have  embraced  this  technology  taking advantage of the    potential    for    re-usable    and interoperable  data.    In  order  to  take  advantage  of XML, each industry is coming up with standard tag terminologies   such   that   the   data   can   be   self describing  and  understandable,  independent  of  the application creating or using it.

Energyplus: new capabilities in a whole-building energy simulation program

A new building energy simulation program developed under support from the US government was released in April 2001. EnergyPlus is based on the most popular features and capabilities of BLAST and DOE-2 but is a completely new program written in Fortran 90.

Energy performance of borehole thermal energy storage systems

This paper describes the energy performance of an underground thermal energy storage system that consists of high efficiency heat pump and Borehole- Heat-Exchangers (BHE). The energy conservation concept of this system is operation of the heat pump at higher efficiency using the Water-Source-Heat- Pump (WSHP). For this concept, the seasonal storage system using BHE under the ground is adopted as a Borehole-Thermal-Energy-Storage-System (BTES) with high efficiency WSHP.

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