# Archive - Day: April 27, 2016

### Show that the diagram efficiency, ?_d, of an impulse turbine is given by: ?_d=4b/a_i (cos??a_i- b/a_i ? ) Where b=mean blade speed a_i=nozzle angle ai=absolute velocity of steam from nozzle

a) i) State any FOUR assumptions made in the theory of torsion. ii) Show that the strain energy ‘u’ stored in a solid shaft of diameter ‘d’, length ‘l’ and….

### Show that the diagram efficiency, ?_d, of an impulse turbine is given by: ?_d=4b/a_i (cos??a_i- b/a_i ? ) Where b=mean blade speed a_i=nozzle angle ai=absolute velocity of steam from nozzle

a) i) State any FOUR assumptions made in the theory of torsion. ii) Show that the strain energy ‘u’ stored in a solid shaft of diameter ‘d’, length ‘l’ and….

### Oil is pumped through a pipe 120mm diameter and 900m long. The pressure difference between the ends is 420KN/m2. The dynamic viscosity of the oil is 1.42 N-S/m2 and the relative density is 0.9. Show that the flow is viscous if Reynold’s number is 2100. Calculate the electric power of the motor required if the mechanical efficiency between the pump and the electric motor is 80%

a) i) State any FOUR assumptions made in the theory of torsion. ii) Show that the strain energy ‘u’ stored in a solid shaft of diameter ‘d’, length ‘l’ and….

### Define the following terms with reference to fluid flow: Critical velocity Reynold’s number ii) Show that the flow rate Q, of a fluid of dynamic viscosity ?, flowing under laminar conditions through a horizontal circular pipe of diameter ‘d’, length ‘L’, with a mean velocity V, when the pressure difference between the ends is P, is given by the expression: Q=(ppd^4)/128?L Hence show that the pressure difference p can be given by the expression P=32?lv/d^2

a) i) State any FOUR assumptions made in the theory of torsion. ii) Show that the strain energy ‘u’ stored in a solid shaft of diameter ‘d’, length ‘l’ and….