Turbomachinery interview questions

1. A.the ratio of the power delivered to the runner to the power supplied by the water jet or flow, isolating losses inside the flow passages
2. B.a turbine in which the whole pressure drop occurs in the nozzle, so the runner sees only a change in kinetic energy at constant pressure
3. C.a violent axial oscillation of the whole flow that sets in when the discharge is throttled past the peak of the pressure-rise characteristic
4. D.an inward mixed-flow reaction turbine with adjustable guide vanes, suited to medium head and medium discharge

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1. A.Specific speed of a turbine
2. B.Pelton wheel
3. C.Impulse turbine
4. D.Surging in a compressor

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1. A.Impulse turbine — an axial-flow reaction turbine with adjustable propeller blades, suited to low head and high discharge
2. B.Impulse turbine — relates the work transferred per unit mass to the change in the product of tangential blade speed and whirl component of absolute velocity between inlet and outlet
3. C.Impulse turbine — the ratio of the power delivered to the runner to the power supplied by the water jet or flow, isolating losses inside the flow passages
4. D.Impulse turbine — a turbine in which the whole pressure drop occurs in the nozzle, so the runner sees only a change in kinetic energy at constant pressure

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1. A.a violent axial oscillation of the whole flow that sets in when the discharge is throttled past the peak of the pressure-rise characteristic
2. B.a gradually expanding outlet passage that recovers part of the exit kinetic energy as suction, letting a reaction turbine sit above the tailrace
3. C.relates the work transferred per unit mass to the change in the product of tangential blade speed and whirl component of absolute velocity between inlet and outlet
4. D.a turbine in which pressure falls in both the fixed and the moving passages, so the runner must run full and be enclosed

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1. A.Kaplan turbine
2. B.Reaction turbine
3. C.Hydraulic efficiency of a turbine
4. D.Pelton wheel

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1. A.Reaction turbine — a turbine in which pressure falls in both the fixed and the moving passages, so the runner must run full and be enclosed
2. B.Reaction turbine — relates the work transferred per unit mass to the change in the product of tangential blade speed and whirl component of absolute velocity between inlet and outlet
3. C.Reaction turbine — a gradually expanding outlet passage that recovers part of the exit kinetic energy as suction, letting a reaction turbine sit above the tailrace
4. D.Reaction turbine — a dimensionless number comparing the net suction head available at a reaction turbine's runner exit to the working head, below whose critical value cavitation begins

Answer + AI explanation with Pro

1. A.the speed of a geometrically similar turbine producing unit power under unit head, the parameter used to select between Pelton, Francis and Kaplan machines
2. B.a tangential-flow impulse turbine with split buckets, suited to high head and low discharge
3. C.a turbine in which pressure falls in both the fixed and the moving passages, so the runner must run full and be enclosed
4. D.the fraction of the total energy change in a stage that occurs as a pressure change within the moving blades, zero for a purely impulse stage

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1. A.Specific speed of a turbine
2. B.Pelton wheel
3. C.Hydraulic efficiency of a turbine
4. D.Thoma's cavitation factor

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1. A.Pelton wheel — a tangential-flow impulse turbine with split buckets, suited to high head and low discharge
2. B.Pelton wheel — a turbine in which the whole pressure drop occurs in the nozzle, so the runner sees only a change in kinetic energy at constant pressure
3. C.Pelton wheel — a violent axial oscillation of the whole flow that sets in when the discharge is throttled past the peak of the pressure-rise characteristic
4. D.Pelton wheel — an inward mixed-flow reaction turbine with adjustable guide vanes, suited to medium head and medium discharge

Answer + AI explanation with Pro

1. A.a turbine in which the whole pressure drop occurs in the nozzle, so the runner sees only a change in kinetic energy at constant pressure
2. B.an axial-flow reaction turbine with adjustable propeller blades, suited to low head and high discharge
3. C.a dimensionless number comparing the net suction head available at a reaction turbine's runner exit to the working head, below whose critical value cavitation begins
4. D.the fraction of the total energy change in a stage that occurs as a pressure change within the moving blades, zero for a purely impulse stage

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1. A.Francis turbine
2. B.Impulse turbine
3. C.Kaplan turbine
4. D.Thoma's cavitation factor

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1. A.Kaplan turbine — a violent axial oscillation of the whole flow that sets in when the discharge is throttled past the peak of the pressure-rise characteristic
2. B.Kaplan turbine — a turbine in which pressure falls in both the fixed and the moving passages, so the runner must run full and be enclosed
3. C.Kaplan turbine — the speed of a geometrically similar turbine producing unit power under unit head, the parameter used to select between Pelton, Francis and Kaplan machines
4. D.Kaplan turbine — an axial-flow reaction turbine with adjustable propeller blades, suited to low head and high discharge

Answer + AI explanation with Pro

1. A.the ratio of the power delivered to the runner to the power supplied by the water jet or flow, isolating losses inside the flow passages
2. B.a dimensionless number comparing the net suction head available at a reaction turbine's runner exit to the working head, below whose critical value cavitation begins
3. C.an inward mixed-flow reaction turbine with adjustable guide vanes, suited to medium head and medium discharge
4. D.a turbine in which the whole pressure drop occurs in the nozzle, so the runner sees only a change in kinetic energy at constant pressure

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1. A.Draft tube
2. B.Francis turbine
3. C.Euler's turbine equation
4. D.Surging in a compressor

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1. A.Francis turbine — a turbine in which pressure falls in both the fixed and the moving passages, so the runner must run full and be enclosed
2. B.Francis turbine — the fraction of the total energy change in a stage that occurs as a pressure change within the moving blades, zero for a purely impulse stage
3. C.Francis turbine — an inward mixed-flow reaction turbine with adjustable guide vanes, suited to medium head and medium discharge
4. D.Francis turbine — relates the work transferred per unit mass to the change in the product of tangential blade speed and whirl component of absolute velocity between inlet and outlet

Answer + AI explanation with Pro

1. A.the ratio of the pitch diameter of a Pelton runner to the diameter of its jet, typically about twelve for good efficiency
2. B.an axial-flow reaction turbine with adjustable propeller blades, suited to low head and high discharge
3. C.a gradually expanding outlet passage that recovers part of the exit kinetic energy as suction, letting a reaction turbine sit above the tailrace
4. D.relates the work transferred per unit mass to the change in the product of tangential blade speed and whirl component of absolute velocity between inlet and outlet

Answer + AI explanation with Pro

1. A.Draft tube
2. B.Reaction turbine
3. C.Impulse turbine
4. D.Pelton wheel

Answer + AI explanation with Pro

1. A.Draft tube — the ratio of the power delivered to the runner to the power supplied by the water jet or flow, isolating losses inside the flow passages
2. B.Draft tube — an inward mixed-flow reaction turbine with adjustable guide vanes, suited to medium head and medium discharge
3. C.Draft tube — a dimensionless number comparing the net suction head available at a reaction turbine's runner exit to the working head, below whose critical value cavitation begins
4. D.Draft tube — a gradually expanding outlet passage that recovers part of the exit kinetic energy as suction, letting a reaction turbine sit above the tailrace

Answer + AI explanation with Pro

1. A.a turbine in which pressure falls in both the fixed and the moving passages, so the runner must run full and be enclosed
2. B.relates the work transferred per unit mass to the change in the product of tangential blade speed and whirl component of absolute velocity between inlet and outlet
3. C.an axial-flow reaction turbine with adjustable propeller blades, suited to low head and high discharge
4. D.the fraction of the total energy change in a stage that occurs as a pressure change within the moving blades, zero for a purely impulse stage

Answer + AI explanation with Pro

1. A.Impulse turbine
2. B.Euler's turbine equation
3. C.Reaction turbine
4. D.Hydraulic efficiency of a turbine

Answer + AI explanation with Pro

1. A.Euler's turbine equation — an inward mixed-flow reaction turbine with adjustable guide vanes, suited to medium head and medium discharge
2. B.Euler's turbine equation — the fraction of the total energy change in a stage that occurs as a pressure change within the moving blades, zero for a purely impulse stage
3. C.Euler's turbine equation — relates the work transferred per unit mass to the change in the product of tangential blade speed and whirl component of absolute velocity between inlet and outlet
4. D.Euler's turbine equation — the ratio of the pitch diameter of a Pelton runner to the diameter of its jet, typically about twelve for good efficiency

Answer + AI explanation with Pro

1. A.a dimensionless number comparing the net suction head available at a reaction turbine's runner exit to the working head, below whose critical value cavitation begins
2. B.an inward mixed-flow reaction turbine with adjustable guide vanes, suited to medium head and medium discharge
3. C.an axial-flow reaction turbine with adjustable propeller blades, suited to low head and high discharge
4. D.the fraction of the total energy change in a stage that occurs as a pressure change within the moving blades, zero for a purely impulse stage

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1. A.Kaplan turbine
2. B.Hydraulic efficiency of a turbine
3. C.Reaction turbine
4. D.Degree of reaction

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1. A.Degree of reaction — the fraction of the total energy change in a stage that occurs as a pressure change within the moving blades, zero for a purely impulse stage
2. B.Degree of reaction — a tangential-flow impulse turbine with split buckets, suited to high head and low discharge
3. C.Degree of reaction — the ratio of the power delivered to the runner to the power supplied by the water jet or flow, isolating losses inside the flow passages
4. D.Degree of reaction — relates the work transferred per unit mass to the change in the product of tangential blade speed and whirl component of absolute velocity between inlet and outlet

Answer + AI explanation with Pro

1. A.the ratio of the pitch diameter of a Pelton runner to the diameter of its jet, typically about twelve for good efficiency
2. B.a gradually expanding outlet passage that recovers part of the exit kinetic energy as suction, letting a reaction turbine sit above the tailrace
3. C.an axial-flow reaction turbine with adjustable propeller blades, suited to low head and high discharge
4. D.the speed of a geometrically similar turbine producing unit power under unit head, the parameter used to select between Pelton, Francis and Kaplan machines

Answer + AI explanation with Pro

1. A.Jet ratio
2. B.Pelton wheel
3. C.Euler's turbine equation
4. D.Reaction turbine

Answer + AI explanation with Pro

1. A.Jet ratio — the ratio of the pitch diameter of a Pelton runner to the diameter of its jet, typically about twelve for good efficiency
2. B.Jet ratio — the speed of a geometrically similar turbine producing unit power under unit head, the parameter used to select between Pelton, Francis and Kaplan machines
3. C.Jet ratio — an inward mixed-flow reaction turbine with adjustable guide vanes, suited to medium head and medium discharge
4. D.Jet ratio — an axial-flow reaction turbine with adjustable propeller blades, suited to low head and high discharge

Answer + AI explanation with Pro

1. A.a turbine in which pressure falls in both the fixed and the moving passages, so the runner must run full and be enclosed
2. B.a violent axial oscillation of the whole flow that sets in when the discharge is throttled past the peak of the pressure-rise characteristic
3. C.the ratio of the pitch diameter of a Pelton runner to the diameter of its jet, typically about twelve for good efficiency
4. D.the speed of a geometrically similar turbine producing unit power under unit head, the parameter used to select between Pelton, Francis and Kaplan machines

Answer + AI explanation with Pro

1. A.Surging in a compressor
2. B.Specific speed of a turbine
3. C.Euler's turbine equation
4. D.Impulse turbine

Answer + AI explanation with Pro

1. A.Specific speed of a turbine — relates the work transferred per unit mass to the change in the product of tangential blade speed and whirl component of absolute velocity between inlet and outlet
2. B.Specific speed of a turbine — a dimensionless number comparing the net suction head available at a reaction turbine's runner exit to the working head, below whose critical value cavitation begins
3. C.Specific speed of a turbine — the speed of a geometrically similar turbine producing unit power under unit head, the parameter used to select between Pelton, Francis and Kaplan machines
4. D.Specific speed of a turbine — the fraction of the total energy change in a stage that occurs as a pressure change within the moving blades, zero for a purely impulse stage

Answer + AI explanation with Pro