Scott Fluid Circuit System Engineering Essay

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To measure the major head losses of the fluid using Scott Fluid Circuit System. As well as, analyzing the relation between the pressure, velocity and the friction arising from the flow.

Abstract:

In this lab, an approach of Reynolds theory was used to determine the head loss within the flow of the fluid suing Scott fluid circuit. The Experiment was conducted using two different sizes of pipes which were Â¾ in and 1 in.

For the Â¾ in, the moody chart was referred for the value of friction factor using the roughness and the Reynolds no. The Roughness curve does tend to close out at Reynolds number = 10^5 after which the curve analysis is required to determine the appropriate friction factor. The experiment did conclude the least possible % error for the venturi meter height of 5.25 inches. Other errors does tend to describe the error in the analysis of the data or some other elements factoring the data collection.

Theory:

According to Reynolds, there are two types of pipe flows:

Laminar Flow

Turbulent Flow

Laminar flows are low in velocity and the fluid particles move in a straight line. Whereas, the turbulent flows are high in velocity and motion of the fluid particles are irregular.

As the fluids are viscous, they lose energy when flowing due to friction. The Pressure loss due to friction is termed as the head loss.

The Flow Rate, Q; Q1 = Q2 = Constant

Or, V1 = V2 = Constant

Change in the Pressure and Gravity can be equated to the head loss, i.e,

Head loss due to friction is in a circular pipe, flowing laminar or turbulent flow for

f=friction factor

L=length of pipe

D=diameter of pipe.

Î½= Kinematic viscosity

And for the Reynolds number , Re = V*D / Î½

Îµ, which is the roughness coefficient related to the roughness of the walls.

And referring to the moody chart relates to the roughness Îµ and the Reynolds number for determining the friction factor, (f).

Manometer

Rotometer

Pump

Venturi Tube

Procedure:

Make sure all equipments are clean.

Task is divided into separate group.

Make sure that the system valves are closed, i.e. If the pipe flow with diameter Â¾ inches is used, make sure that the valves other pipes are closed. This way there will be no leakage in the system.

Recording the pressure levels and make sure that there is no back pressure build in the pump and that all flow is continuous.

Data Analysis & Calculations:

Sample calculation using major Â¾ inches

First convert âˆ†P in inches to ft:

Flow rate = Q =

Flow Rate = Q =

Flow Rate = Q = 0.018364 ft3 / sec

Converting Flow Rate from (ft3 / sec) to (gallons / minute)

448.8311688 ft3/s/g/m * .015 ft3/s = 8.242475 gallons / minute

Velocity = Flow Rate / Area = Q / A = .015 ft3 / sec / .003360986 ft2 = 5.463979 ft / sec

Reynolds Number = (v * D) / Î½ = (4.556 ft / sec * 1.025 * 1 ft / 12 in) / (.000011 ft2 / sec) = 42428.63

Friction Factor = Recorded using Moody Chart = 0.0217

Head Loss = f * (L / D) * (V2 / 2 * g)

Head Loss = 0.0217 * (5 ft / 1.025 in * 1 ft / 12 in) * ((5.463979 ft/sec) 2 / 2 * 32.2 ft / sec2)

Indicated Head Loss = 0.541667 ft

Error Analysis:

% Error = [Experimental value - Actual Value] / [Actual Value] * 100 %

% Error = [0.58887 - 0.541667] / [0.541667] *100 % = 8.714433 %

Conclusion:

The data collected and calculated results do coagulate the equation, hf = f * (L / d) * (V2 / 2 * g), showing that pipe head loss equals the change in the sum of pressure and gravity head. Hence, it can be said that the friction factor is a function of the Reynolds Number, and hence the roughness factor is valid.