I created a diagram of 5 scenarios in which I would like to understand how their variations would affect air flow and suction. Examples attached to post or link to examples: http://s29.postimg.org/kua3svg2f/understanding_airflow.png So onto the actual question, how will air flow and suction be effected in each of the scenarios? How can I maximize suction and speed at which the air is exhausted with the fan that I am using? My assumptions about each scenario is listed below. I could be wrong so please correct me or offer more information. Side note, I find fluid mechanics interesting however my knowledge on it is limited. I haven't ever taken a physics class but its a subject that I may take as a course at my university because of its practicality. Ex. 2: Since the outlet is narrowed at the end, then the velocity of the air stream would be increased as the tube narrows. Does the angle at which the frustum narrows effect it? Ex. 3: Since the inlet is narrowed at the beginning, then the suction strength is increased but the area of suction is decreased. Ex. 4: This will increase the velocity of the air flow to the same speed as in Ex. 2 and the suction strength will also be increased the same way as in Ex. 3. Ex. 5: I created this example to understand the Venturi effect a little more. In this example the fan pulls air in, which is then narrowed to increase the velocity of the air flow before being funneled into a straight cylinder at an angle. Following the Venturi effect this should create suction at the bottom of the cylinder and exhaust (for a lack of a better word) at the end. If that reaction occurs than what factors regarding the diagram design could be adjusted to increase suction (like lengths of the cylinder or angle of the T joint)? If anyone can offer easy to use software where I can simulate these events, that would be fantastic. However I lack terminology to operate and understand the CFD software that I have looked into.