Transient modelling of convective movements in a dwelling cell

Numerical modelling of convective air movements inside a heated room was built, using a coupling of a zonal model and integral analysis. The model describes the heat transfer between air and walls, between different air layers inside the room, between air in the room and cold air jet from ventilation air supply, and between air and heat emitter. Experiments were conducted in a testing chamber with floor heating or heating by a hot water radiator, with steps in hot water and ventilation flow rates. Validation results are satisfying.

Cold downdraughts.

Simulation of thermal coupling between a radiator and a room with zonal models.

Zonal models are a promising way to predict air movement, in a room with respect to comfort conditions and gradient of temperature, because they require extremely low computer time and may be therefore rather easily included in multizone air movement models. The main objective of this paper is to study the ability of the zonal models to predict the thermal behaviour of air in case of natural convection coupled with a radiator. First, we present simplified two zone and five zone models.

Modelling of boundary conditions near the radiator.

In this paper information is provided about ways to model the boundary conditions near the radiator for use in the flow simulation program. Due to lack of time the modelling is restricted to the thermal behaviour of a single plane radiator as selected in 'R.I. 1.4 : Selection of radiator'. Ways to model the flow near the radiator with e.g. hot and cold wall jets have not been investigated.

Selection of radiator.

In this paper a proposal has been made for the radiator to be used for the measurements and numerical simulations of test case d: 'free convection with radiator'. The selection of the radiator is based on the identical testroom configuration as described in 'R.I. 1.3 : Test room, identical testrooms'. Thisconfiguration consists of a window with single glazing. However data for double glazing is also presented. A radiator of a well known manufacturer has been chosen, in order to make sure that the radiator is available in each participating country.

Calculation of the air flow pattern in a proposed new European test chamber for radiators.

A new European norm for measuring the heat transfer rate of radiators is under discussion [ CEN TC 130 ]. This testing can be done either in a closed chamber with cooled walls or in a open chamber with a controlled air supply. The air flow pattern around a typical radiator is calculated for both types of chambers. The calculation is done with the program PHOENICS, a finite volume program that solves the conservation equations for mass, momentum and energy. For turbulence, the k-E model is used with the Lam-Bremhorst correction for low Reynolds numbers.