modelling

In this paper the use of a thin adsorbent sheet composed of activated carbon particles to purify indoor air is modelled. A loose sheet with high porosity appears more effective than a dense one. The carbon sheet can be replaced by a fresh sheet after a certain period of use, thus keeping the volatile organic compound (VOC) level low in the remaining years. The model has been used to predict the optimal replacement time. Binary VOCs are modelled.

Adsorption, desorption and chemisorption are known to impact the dispersal of volatile organic and chemically reactive compounds in buildings. These same three processes may be used to advantage to control the levels of these compounds indoors using building sorption filtration devices.

There is a need to calculate root mean square (r.m.s.) pressures from the output of steady-state computer programs. We know much less about calculating r.m.s. pressures than about calculating r.m.s. velocities. R.m.s. pressures can be quickly estimated from calculated mean pressures, mean velocities and r.m.s. velocities using the equations in this paper. The equations have been used in \Mind Engineering but can be applied in any turbulent flow where pressures are required.

Flowfields around bluff bodies are characterized by complex distributions of the strain-rate tensor. Such flowfields can be analyzed with various turbulence models. The shortcoming of the eddy viscosity modelling in the k-e model is scrutinized in comparison with the results of ASM. The accuracy of the algebraic approximation adopted in ASM is examined using the numerical data given from LES. A new LES model with variable Smagorinsky constant is then presented.