I've been given a project to improve the design of a turbine used to measure the flow of beer! I've trawled the web and libraries to find previous work in the hope of finding some handy pointers, rules of thumb and simple equations to guide me. However, I've had little joy. Basic parameters are: - flow rate range: 5 to 60 seconds per pint (0.56812 litres) - inner diameter of bore = 8.9mm The design variables that I've got to play with include: - blade angle (should I go for high or low angle of attack to improve response at low speeds?) - hub diamater - tip clearance - shape of leading and trailing profile of the hub (hemisphere on the front? flat on the back? what effect does the wake profile have?) If you can point in the right directions then that would be great! e.g. journal articles, textbooks, web resources etc.