I am currently trying to use a centrifugal fan to force air through a small tube however i am looking for some information on how to better the design and performance as what i have currently is severely lack-lustre. This is just a prototype for controlling rate of airflow and all i had on hand was a tin with some tubing hence the god-awful design. The issue is that the air making it out of the tube is less than desired, as it seems more air is forced from the fan outwards towards northwest (according to the diagram, if that makes any sense) rather than into the tin and out of the tube. I am to change the design but i am unsure what is the best approach. I will get a more suitable fan (is a pump better?) as mine is certainly powerful enough - but it is overkill for what i need. it is the airflow that is hindering the performance. I think need to find a better way to direct the airflow in a gradual reduction in diameter/volume rather than blast air into a tin and use the pressure to force air through the tube. Are there any software tools than can aid with design or simulation of fluid flow? Thanks for reading, any input is greatly appreciated!