rubbishbox
New Member
Does anyone know how to calculate the capacity constant for a water brake dynamometer. I am using the article "The basic theory of Hydraulic Dynamometers and Retarders" : The Basic Theory of Hydraulic Dynamometers and Retarders on JSTOR. I'm really struggling to determine the K value to then determine the nominal diameter. Does anyone have experience designing a dyno using this as a guide?
T = KN^2 D^5 (T = torque, K = capacity constant, D = diameter)
Is the blade angle used the angle at which the water exits the torus pocket?
r = RI/RO with (R=Radius, I=Inner, O=Outer) but this doesn't seem to have anything to do with the torus inner and outer radius but rather the radius of the design path which is defined as rd=fn(theta) with fn being the coefficient of friction.
Any alternative methods for determining torus shape and impeller dimensions are appreciated as well.
Am I also overdesigning this. The Engine to be tested is a Honda GXH50 which only has 2.1 hp. Would it be better to just design a straight vane impeller as the rotor with some vanes or pockets on the stator to help with the transfer of momentum. Can then just use the general centrifugal pump calculations to determine the diameter required for the impeller.
T = KN^2 D^5 (T = torque, K = capacity constant, D = diameter)
Is the blade angle used the angle at which the water exits the torus pocket?
r = RI/RO with (R=Radius, I=Inner, O=Outer) but this doesn't seem to have anything to do with the torus inner and outer radius but rather the radius of the design path which is defined as rd=fn(theta) with fn being the coefficient of friction.
Any alternative methods for determining torus shape and impeller dimensions are appreciated as well.
Am I also overdesigning this. The Engine to be tested is a Honda GXH50 which only has 2.1 hp. Would it be better to just design a straight vane impeller as the rotor with some vanes or pockets on the stator to help with the transfer of momentum. Can then just use the general centrifugal pump calculations to determine the diameter required for the impeller.
