about theta angle in bladegen
 

i am a newer to bladegen, i cannot understand what is the theta angle. i am totally confused. can you help me? thanks!

Let say you have a guide vane of the turbine in xy plane. Z is axis of rotation. The leading edge and trailing edge (LE and TE) are defined by the line in zx plane and by the theta angle (and can also be defined by beta angle). Theta determines a line from x+ axis (it is like polar coordinates). Theta is the angle between a line and x+ axis. For example if the turbine guide vane LE has theta 0°, the point of LE lies on x axis, if 90° it lies on y axis.