Model experiments with low Reynolds number effects in a ventilated room.

The flow in a ventilated room will not always be a fully developed turbulent flow. Reduced air change rates owing to energy considerations and the application of natural ventilation with openings in the outer wall will give room air movements with low turbulence effects. This paper discusses the isothermal low Reynolds number flow from a slot inlet in the end wall of the room. The experiments are made on the scale of I to 5. Measurements indicate a low Reynolds number effect in the wall jet flow. The virtual origin of the wall jet moves forward in front of the opening at a small Reynolds number, an effect that is also known from measurements on free jets. The growth rate of the jet, or the length scale, increases and the velocity decay factor decreases at small Reynolds numbers.