Sketched in Fig. P12.6 are the upstream [section (1)] and downstream [section (2)] velocity triangles at the arithmetic mean radius for flow through an axial-flow turbomachine rotor. The axial component of velocity is \(50 \mathrm{ft} / \mathrm{s}\) at sections (1) and (2).

(a) Label each velocity vector appropriately. Use \(\mathbf{V}\) for absolute velocity, \(\mathbf{W}\) for relative velocity, and \(\mathbf{U}\) for blade velocity.

(b) Are you dealing with a turbine or a fan?

(c) Calculate the work per unit mass involved.

(d) Sketch a reasonable blade section. Do you think that the actual blade exit angle will need to be less or greater than \(15^{\circ}\) ? Why?

Figure P12.6

Transcribed Image Text:

(1) 15 (2) /30 15 Axial direction