ESP-r: Convection

Current capabilities

• For internal convection:
  - time invariant values can be specified (in expert mode)
  - schedules of imposed values can be specified (in expert mode)
  - time varying values are used by default with Alamdari and Hammond correlations typically used
  - alternative regimes based on the work of Ian Beausoleil-Morrison.
  - time varying values can be derived from a simultaneous CFD solution of the model
• For external convection
  time varying wind driven convection coefficients calculated with a choice of two different correlations.

Primary routines

• esrubld/convect1.F - controlling routines for simulation time calculation
• esrubld/convect2.F - htc correlations

Primary variables

• COMMON/CONCOE - present and future values of internal and external htc
• COMMON/CONVS - present values of internal and external htc
• COMMON/CORIND - correlation index for internal and external surfaces

Issues arising

• Internal convection modelling has been the subject of considerable research (2 PhD's from ESRU alone). There are, however, only a limited number of example models and supporting documents. The relationship between the alternative convective regimes and control is opaque.
• There is, as yet, no link between predictions from a flow network and air velocity within zones.
• External convection modelling is less well developed and could be improved by more careful consideration of building micro climate issues.
• Links with comfort calculations could be extended - possible link to control?

Last edited April 2005