Apparatus required :

CCL₄ manometer, H_g manometer.

Procedure :

• Keep the bypass valve completely open and the main valve completely closed. Switch on the pump.
• Connect a CCL₄ manometer, H_gmanometer across the venturi.
• Open the main valve and set a flow rate of water using the rotameter.
• Note down the rotameter reading and manometer reading after a steady state is attained.
• Increase the flow rate by opening the main valve and throttling the bypass valve suitably and repeat step 4.
• Use mercury manometer for higher flow rates.
• Take readings with CCL₄ manometer, H_g manometer as well as with H_g manometer.
• Repeat the experiment with different ratios and with different fluids.

Data :

Diameter of the pipe = d =           cm
Diameter of the venture throat= d_t=           cm
Density of CCL₄ =_CCL4 =           kg/m³

Density of Hg =_Hg =           kg/m³
Density of fluid = =           kg/m³
Viscosity of fluid = =           cp

Observations :

Calculations :

Flow rate: Hm= cm of manometric fluid.

Volumetric flow rate = Q = m³/s
=   m of H₂o
_m= density of manometric fluid.

Average velocity through the throat =V_t=Q/A_t=    m/s
A_t = Cross sectional area of throat =  
=d_t/d=

Reynolds Number at the throat = <img src="images/CodeCogsEqn126.gif"style="width:101px;height:42px"> =

Coefficient of discharge = C_d =

Plot Q vs and Q vs on ordinary graph(calibration).

Plot C_d vs N_Ret on a semilog graph sheet (with N_Reton log scale).

Plot log Q vs log .Find the slope and the intercept. Find the coefficient and power of . Comment on the nonlinear flow head relationship. Obtain C_d from the plot.

Results :

• Report on calibration
• Comment on C_d vs N_Ret
• Report the C_d
• Comment on flow head relationship
• compare C_d for orifice and venturimeter