Problem 1: Pump Total Head from Flange Measurements

Water passes through a pump. At the suction flange, gauge pressure is p1=−20.0 kPap_1=-20.0\text{ kPa}, velocity is V1=2.00 m/sV_1=2.00\text{ m/s}, and elevation is z1=0z_1=0. At the discharge flange, p2=250 kPap_2=250\text{ kPa}, V2=3.00 m/sV_2=3.00\text{ m/s}, and z2=5.00 mz_2=5.00\text{ m}. Take α1=α2=1\alpha_1=\alpha_2=1 and γ=9.81 kN/m3\gamma=9.81\text{ kN/m}^3. Determine pump total head.

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Problem 2: Water, Shaft, and Electrical Input Power

A pump delivers 50.0 L/s50.0\text{ L/s} of water against a total dynamic head of 40.0 m40.0\text{ m}. Pump efficiency is 75.0%75.0\% and motor efficiency is 90.0%90.0\%. Determine water power, shaft power, and electrical input power.

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Problem 3: Pump Efficiency from Test Data

A pump delivers 0.0800 m3/s0.0800\text{ m}^3/\text{s} against 25.0 m25.0\text{ m} head while absorbing 30.0 kW30.0\text{ kW} of shaft power. Determine pump efficiency.

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Problem 4: Single-Pump Operating Point

A pump curve is approximated by Hp=50−0.020Q2H_p=50-0.020Q^2 and the connected system by Hsys=10+0.010Q2H_{\text{sys}}=10+0.010Q^2, with HH in metres and QQ in L/s\text{L/s}. Determine the operating flow and head.

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Problem 5: Two Identical Pumps in Series

Each pump has H=40−0.010Q2H=40-0.010Q^2, where HH is in metres and QQ in L/s\text{L/s}. The system curve is Hsys=20+0.015Q2H_{\text{sys}}=20+0.015Q^2. Determine the operating point for two identical pumps in series.

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Problem 6: Two Identical Pumps in Parallel

Each pump has H=50−0.020q2H=50-0.020q^2, where qq is one-pump discharge in L/s\text{L/s}. The system curve is Hsys=10+0.010Q2H_{\text{sys}}=10+0.010Q^2, where QQ is total station discharge. Determine the operating point for two identical pumps in parallel.

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Problem 7: Variable Speed Changes the Pump-System Intersection

At 1200 rpm1200\text{ rpm} a pump curve is Hp=40−0.010Q2H_p=40-0.010Q^2, with HH in metres and QQ in L/s\text{L/s}. The system curve is Hsys=5+0.005Q2H_{\text{sys}}=5+0.005Q^2. Estimate the operating point at 1200 rpm1200\text{ rpm} and after reducing speed to 900 rpm900\text{ rpm}.

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Problem 8: Modest Impeller Trim Estimate

A centrifugal pump at constant speed delivers Q1=0.100 m3/sQ_1=0.100\text{ m}^3/\text{s} at H1=30.0 mH_1=30.0\text{ m} and absorbs P1=40.0 kWP_1=40.0\text{ kW} with impeller diameter D1=300 mmD_1=300\text{ mm}. Estimate performance after a modest trim to D2=270 mmD_2=270\text{ mm}.

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Problem 9: NPSH Available from an Open Reservoir

A pump draws water from an open reservoir. Atmospheric pressure head is 10.3 m10.3\text{ m} of water, vapor-pressure head is 0.240 m0.240\text{ m}, the pump centerline is 3.00 m3.00\text{ m} above the reservoir surface, and suction-line loss is 1.20 m1.20\text{ m}. Determine NPSHANPSH_A and compare it with NPSHR=4.20 mNPSH_R=4.20\text{ m}.

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Problem 10: Effect of Altitude and Temperature on NPSH Margin

At a higher-elevation, warmer installation, atmospheric pressure head is 8.50 m8.50\text{ m}, vapor-pressure head is 0.500 m0.500\text{ m}, suction lift is 2.00 m2.00\text{ m}, and suction loss is 1.00 m1.00\text{ m}. The pump has NPSHR=4.50 mNPSH_R=4.50\text{ m} at the proposed flow. Determine NPSHANPSH_A and the numerical excess above NPSHRNPSH_R.

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Problem 11: Conventional and Dimensionless Pump Specific Speed

A pump operates at N=1450 rpmN=1450\text{ rpm}, Q=0.100 m3/sQ=0.100\text{ m}^3/\text{s}, and H=30.0 mH=30.0\text{ m} at BEP. Calculate the conventional metric index Ns=NQ/H3/4N_s=N\sqrt{Q}/H^{3/4} and the dimensionless pump specific speed Ωs=ωQ/(gH)3/4\Omega_s=\omega\sqrt Q/(gH)^{3/4}.

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Problem 12: Euler Head from a Velocity Triangle

For a centrifugal pump, inlet whirl is negligible so Vθ1=0V_{\theta1}=0. At the impeller outlet, blade speed is u2=20.0 m/su_2=20.0\text{ m/s} and tangential absolute velocity is Vθ2=15.0 m/sV_{\theta2}=15.0\text{ m/s}. Determine ideal Euler head. If hydraulic efficiency relative to Euler head is 85.0%85.0\%, estimate actual developed head.

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Problem 13: Turbine Shaft and Generator Output

A turbine receives 3.00 m3/s3.00\text{ m}^3/\text{s} of water under net head Hn=40.0 mH_n=40.0\text{ m}. Turbine efficiency is 90.0%90.0\% and generator efficiency is 96.0%96.0\%. Determine shaft power and electrical output.

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