Fluid Mechanics and Hydraulic Machinery Miscellaneous
 For a Newtonian fluid

View Hint View Answer Discuss in Forum
For a Newtonian fluid, shear stress is proportional to rate of shear strain.
Correct Option: C
For a Newtonian fluid, shear stress is proportional to rate of shear strain.
 Kaplan water turbine is commonly used when the flow through its runner is

View Hint View Answer Discuss in Forum
Kaplan turbine is an axial flow turbine and works at low heads (<50).
Correct Option: B
Kaplan turbine is an axial flow turbine and works at low heads (<50).
 In order to have maximum power from a Pelton turbine, the bucket speed must be

View Hint View Answer Discuss in Forum
For a pelton wheel, maximum power is obtained at,
u = υ 2 Correct Option: B
For a pelton wheel, maximum power is obtained at,
u = υ 2
 The velocity triangles at the inlet and exit of the rotor of a turbo machine are shown. V denotes the absolute velocity of the fluid, W denotes the relative velocity of the fluid and U denotes the blade velocity. Subscripts 1 and 2 refer to inlet and outlet respectively If V_{2} = W_{1} and V_{1} = W_{2}, then the degree of reaction is

View Hint View Answer Discuss in Forum
DOR = W_{2}² −W_{1}² 2/W_{2}² −W_{1}² = 1 = 0.5 2 Correct Option: C
DOR = W_{2}² −W_{1}² 2/W_{2}² −W_{1}² = 1 = 0.5 2
 A hydraulic turbine develops 1000 kW power for a head of 40 m. If the head is reduced to 20 m, the power developed (in kW) is

View Hint View Answer Discuss in Forum
P_{u} = P H^{3/2} ∴ P_{1} = P_{2} H_{1}^{3/2} H_{2}^{3/2}
⇒ P_{2} = 353.55 kW.Correct Option: B
P_{u} = P H^{3/2} ∴ P_{1} = P_{2} H_{1}^{3/2} H_{2}^{3/2}
⇒ P_{2} = 353.55 kW.