I am designing an almond dehydrator as a part of my university project and need some advice regarding air flow in the dehydrator. There is a hollow perforated cylinder with a heating device in the middle. This cylinder is divided into two sections. The lower section has to take in cool air from the environment. This air is passed through the heating device to heat the air.. Then, the upper section passes this air out of the perforations.. I am not able to get the air to flow uniformly throughout the holes in the cylinder. Please reply, its very urgent.. Thanks..