Prediction of airflow rate through a ventilated wall module

• A ventilated wall module to filter the drawn outdoor air and insulate noise.
• Combination of a solar channel with a porous filtration unit.
• Efficient and accurate prediction of the drawn outdoor air rate by a correlation model.
• Flow instability and recirculation generate dynamic flow resistance.

When outdoor air becomes polluted by airborne particles and noise, it is necessary to use a new type of outdoor air intake device that is able to clean the extracted air and insulate the noise. One possibility is to adopt a ventilated wall module that contains a porous filtration unit. To use solar irradiation, a solar channel is attached to the ventilated wall module to heat the air and to propel the air movement. The driving force of air ventilation can be the stack pressure, the wind pressure, a combination of the two, or external fans. This investigation developed a lumped correlation analysis model to predict the volumetric flow rates versus the driving pressure. The correlation model was established based on energy conservation and pressure balance laws. In addition, the computational fluid dynamics (CFD) modeling was also implemented to predict the ventilated wall performance. To validate both types of models, a ventilated wall prototype model was constructed in the lab. Both pressures and induced volumetric flow rates were measured by a high-precision micro-manometer. It is found that the correlation analysis model obtained results in reasonably good agreement with the experimental data, which suffices for engineering design.

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