Fluid Mechanics & Transport interview questions

1. A.dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000
2. B.manufacturer plot of head, efficiency and power against flow rate; the operating point is where it intersects the system resistance curve
3. C.energy balance for steady inviscid incompressible flow stating that pressure head, velocity head and elevation head sum to a constant along a streamline
4. D.laminar pipe-flow relation in which pressure drop is proportional to viscosity, length and flow rate and inversely to the fourth power of diameter

Answer + AI explanation with Pro

1. A.Orifice meter vs venturi
2. B.Reynolds number
3. C.Fanning friction factor
4. D.Affinity laws

Answer + AI explanation with Pro

1. A.Reynolds number — dimensionless wall-shear parameter equal to 16/Re in laminar flow and one quarter of the Darcy factor, used in the ΔP = 4f(L/D)(ρv²/2) equation
2. B.Reynolds number — energy balance for steady inviscid incompressible flow stating that pressure head, velocity head and elevation head sum to a constant along a streamline
3. C.Reynolds number — manufacturer plot of head, efficiency and power against flow rate; the operating point is where it intersects the system resistance curve
4. D.Reynolds number — dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000

Answer + AI explanation with Pro

1. A.vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required
2. B.dimensionless wall-shear parameter equal to 16/Re in laminar flow and one quarter of the Darcy factor, used in the ΔP = 4f(L/D)(ρv²/2) equation
3. C.energy balance for steady inviscid incompressible flow stating that pressure head, velocity head and elevation head sum to a constant along a streamline
4. D.laminar pipe-flow relation in which pressure drop is proportional to viscosity, length and flow rate and inversely to the fourth power of diameter

Answer + AI explanation with Pro

1. A.Bernoulli equation
2. B.Fanning friction factor
3. C.Reynolds number
4. D.Orifice meter vs venturi

Answer + AI explanation with Pro

1. A.Bernoulli equation — dimensionless wall-shear parameter equal to 16/Re in laminar flow and one quarter of the Darcy factor, used in the ΔP = 4f(L/D)(ρv²/2) equation
2. B.Bernoulli equation — laminar pipe-flow relation in which pressure drop is proportional to viscosity, length and flow rate and inversely to the fourth power of diameter
3. C.Bernoulli equation — energy balance for steady inviscid incompressible flow stating that pressure head, velocity head and elevation head sum to a constant along a streamline
4. D.Bernoulli equation — orifice plate is cheap but wastes most of its differential as permanent loss (coefficient about 0.61); venturi recovers pressure with a coefficient near 0.98

Answer + AI explanation with Pro

1. A.dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000
2. B.vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required
3. C.centrifugal pump flow varies with speed, head with speed squared and power with speed cubed, which is the basis of VFD energy savings
4. D.fluid whose shear stress is directly proportional to shear rate, so viscosity stays constant at a fixed temperature, as for water and air

Answer + AI explanation with Pro

1. A.Orifice meter vs venturi
2. B.Reynolds number
3. C.Cavitation
4. D.Newtonian fluid

Answer + AI explanation with Pro

1. A.Newtonian fluid — vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required
2. B.Newtonian fluid — fluid whose shear stress is directly proportional to shear rate, so viscosity stays constant at a fixed temperature, as for water and air
3. C.Newtonian fluid — energy balance for steady inviscid incompressible flow stating that pressure head, velocity head and elevation head sum to a constant along a streamline
4. D.Newtonian fluid — dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000

Answer + AI explanation with Pro

1. A.laminar pipe-flow relation in which pressure drop is proportional to viscosity, length and flow rate and inversely to the fourth power of diameter
2. B.dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000
3. C.centrifugal pump flow varies with speed, head with speed squared and power with speed cubed, which is the basis of VFD energy savings
4. D.vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required

Answer + AI explanation with Pro

1. A.Orifice meter vs venturi
2. B.Hagen-Poiseuille equation
3. C.Bernoulli equation
4. D.Cavitation

Answer + AI explanation with Pro

1. A.Hagen-Poiseuille equation — energy balance for steady inviscid incompressible flow stating that pressure head, velocity head and elevation head sum to a constant along a streamline
2. B.Hagen-Poiseuille equation — laminar pipe-flow relation in which pressure drop is proportional to viscosity, length and flow rate and inversely to the fourth power of diameter
3. C.Hagen-Poiseuille equation — dimensionless wall-shear parameter equal to 16/Re in laminar flow and one quarter of the Darcy factor, used in the ΔP = 4f(L/D)(ρv²/2) equation
4. D.Hagen-Poiseuille equation — fluid whose shear stress is directly proportional to shear rate, so viscosity stays constant at a fixed temperature, as for water and air

Answer + AI explanation with Pro

1. A.dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000
2. B.fluid whose shear stress is directly proportional to shear rate, so viscosity stays constant at a fixed temperature, as for water and air
3. C.vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required
4. D.dimensionless wall-shear parameter equal to 16/Re in laminar flow and one quarter of the Darcy factor, used in the ΔP = 4f(L/D)(ρv²/2) equation

Answer + AI explanation with Pro

1. A.Affinity laws
2. B.Fanning friction factor
3. C.Reynolds number
4. D.Hagen-Poiseuille equation

Answer + AI explanation with Pro

1. A.Fanning friction factor — centrifugal pump flow varies with speed, head with speed squared and power with speed cubed, which is the basis of VFD energy savings
2. B.Fanning friction factor — manufacturer plot of head, efficiency and power against flow rate; the operating point is where it intersects the system resistance curve
3. C.Fanning friction factor — dimensionless wall-shear parameter equal to 16/Re in laminar flow and one quarter of the Darcy factor, used in the ΔP = 4f(L/D)(ρv²/2) equation
4. D.Fanning friction factor — vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required

Answer + AI explanation with Pro

1. A.fluid whose shear stress is directly proportional to shear rate, so viscosity stays constant at a fixed temperature, as for water and air
2. B.centrifugal pump flow varies with speed, head with speed squared and power with speed cubed, which is the basis of VFD energy savings
3. C.manufacturer plot of head, efficiency and power against flow rate; the operating point is where it intersects the system resistance curve
4. D.orifice plate is cheap but wastes most of its differential as permanent loss (coefficient about 0.61); venturi recovers pressure with a coefficient near 0.98

Answer + AI explanation with Pro

1. A.Orifice meter vs venturi
2. B.Affinity laws
3. C.Bernoulli equation
4. D.Hagen-Poiseuille equation

Answer + AI explanation with Pro

1. A.Orifice meter vs venturi — fluid whose shear stress is directly proportional to shear rate, so viscosity stays constant at a fixed temperature, as for water and air
2. B.Orifice meter vs venturi — manufacturer plot of head, efficiency and power against flow rate; the operating point is where it intersects the system resistance curve
3. C.Orifice meter vs venturi — energy balance for steady inviscid incompressible flow stating that pressure head, velocity head and elevation head sum to a constant along a streamline
4. D.Orifice meter vs venturi — orifice plate is cheap but wastes most of its differential as permanent loss (coefficient about 0.61); venturi recovers pressure with a coefficient near 0.98

Answer + AI explanation with Pro

1. A.dimensionless wall-shear parameter equal to 16/Re in laminar flow and one quarter of the Darcy factor, used in the ΔP = 4f(L/D)(ρv²/2) equation
2. B.dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000
3. C.vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required
4. D.manufacturer plot of head, efficiency and power against flow rate; the operating point is where it intersects the system resistance curve

Answer + AI explanation with Pro

1. A.Hagen-Poiseuille equation
2. B.Newtonian fluid
3. C.Pump characteristic curve
4. D.Fanning friction factor

Answer + AI explanation with Pro

1. A.Pump characteristic curve — manufacturer plot of head, efficiency and power against flow rate; the operating point is where it intersects the system resistance curve
2. B.Pump characteristic curve — fluid whose shear stress is directly proportional to shear rate, so viscosity stays constant at a fixed temperature, as for water and air
3. C.Pump characteristic curve — centrifugal pump flow varies with speed, head with speed squared and power with speed cubed, which is the basis of VFD energy savings
4. D.Pump characteristic curve — dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000

Answer + AI explanation with Pro

1. A.laminar pipe-flow relation in which pressure drop is proportional to viscosity, length and flow rate and inversely to the fourth power of diameter
2. B.energy balance for steady inviscid incompressible flow stating that pressure head, velocity head and elevation head sum to a constant along a streamline
3. C.dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000
4. D.vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required

Answer + AI explanation with Pro

1. A.Fanning friction factor
2. B.Cavitation
3. C.Reynolds number
4. D.Bernoulli equation

Answer + AI explanation with Pro

1. A.Cavitation — dimensionless wall-shear parameter equal to 16/Re in laminar flow and one quarter of the Darcy factor, used in the ΔP = 4f(L/D)(ρv²/2) equation
2. B.Cavitation — dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000
3. C.Cavitation — vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required
4. D.Cavitation — orifice plate is cheap but wastes most of its differential as permanent loss (coefficient about 0.61); venturi recovers pressure with a coefficient near 0.98

Answer + AI explanation with Pro

1. A.fluid whose shear stress is directly proportional to shear rate, so viscosity stays constant at a fixed temperature, as for water and air
2. B.dimensionless ratio of inertial to viscous forces (ρvD/μ); pipe flow is laminar below about 2100 and fully turbulent above roughly 4000
3. C.centrifugal pump flow varies with speed, head with speed squared and power with speed cubed, which is the basis of VFD energy savings
4. D.orifice plate is cheap but wastes most of its differential as permanent loss (coefficient about 0.61); venturi recovers pressure with a coefficient near 0.98

Answer + AI explanation with Pro

1. A.Cavitation
2. B.Reynolds number
3. C.Affinity laws
4. D.Bernoulli equation

Answer + AI explanation with Pro

1. A.Affinity laws — vapour bubbles forming and collapsing when suction pressure falls below liquid vapour pressure, pitting the impeller; prevented by keeping NPSH available above NPSH required
2. B.Affinity laws — orifice plate is cheap but wastes most of its differential as permanent loss (coefficient about 0.61); venturi recovers pressure with a coefficient near 0.98
3. C.Affinity laws — centrifugal pump flow varies with speed, head with speed squared and power with speed cubed, which is the basis of VFD energy savings
4. D.Affinity laws — dimensionless wall-shear parameter equal to 16/Re in laminar flow and one quarter of the Darcy factor, used in the ΔP = 4f(L/D)(ρv²/2) equation

Answer + AI explanation with Pro