Transition from laminar flow to turbulent flow is aided by the (A) Surface roughness and curvature (i.e. sharp corners) (B) Vibration (C) Pressure gradient and the compressibility of the flowing medium (D) All (A), (B) & (C)

Transition from laminar flow to turbulent flow is aided by the
(A) Surface roughness and curvature (i.e. sharp corners)
(B) Vibration
(C) Pressure gradient and the compressibility of the flowing medium
(D) All (A), (B) & (C)
by

1 Answer

Answer :

(D) All (A), (B) & (C)
by

Related questions

In turbulent flow, a rough pipe has the same friction factor as a smooth pipe (A) In the zone of complete turbulence (B) When the roughness projections are much smaller than the thickness of the laminar film (C) Everywhere in the transition zone (D) When the friction factor is independent of the Reynold's number

Description : In turbulent flow, a rough pipe has the same friction factor as a smooth pipe (A) In the zone of complete turbulence (B) When the roughness projections are much smaller than the thickness of ... ) Everywhere in the transition zone (D) When the friction factor is independent of the Reynold's number

Last Answer : (B) When the roughness projections are much smaller than the thickness of the laminar film

Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone. (A) Laminar (B) Transition (C) Both 'a' & 'b' (D) Highly turbulent

Description : Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone. (A) Laminar (B) Transition (C) Both 'a' & 'b' (D) Highly turbulent

Last Answer : (D) Highly turbulent

The laminar boundary layer thickness in zero pressure gradient flow over a flat plate along the x-direction varies as x0.5 while the thickness of turbulent boundary layer varies as (where, x = distance from the leading edge) (A) x1.5 (B) x0.8 (C) x-1.5 (D) x-0.8

Description : The laminar boundary layer thickness in zero pressure gradient flow over a flat plate along the x-direction varies as x0.5 while the thickness of turbulent boundary layer varies as (where, x = distance from the leading edge) (A) x1.5 (B) x0.8 (C) x-1.5 (D) x-0.8

Last Answer : (B) x0.8

Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer. (A) Grashoff (B) Reynolds (C) Both 'a' & 'b' (D) Prandtl & Grashoff

Description : Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer. (A) Grashoff (B) Reynolds (C) Both 'a' & 'b' (D) Prandtl & Grashoff

Last Answer : (D) Prandtl & Grashoff

Maximum heat transfer rate is obtained in __________ flow. (A) Laminar (B) Turbulent (C) Creeping (D) Transition region

Description : Maximum heat transfer rate is obtained in __________ flow. (A) Laminar (B) Turbulent (C) Creeping (D) Transition region

Last Answer : (B) Turbulent

Fanning equation is given by (∆P/ρ) = 4f (L/D) (v 2 /2gc ). It is applicable to __________ region flow. (A) Transition (B) Laminar (C) Turbulent (D) Both (B) and (C)

Description : Fanning equation is given by (∆P/ρ) = 4f (L/D) (v 2 /2gc ). It is applicable to __________ region flow. (A) Transition (B) Laminar (C) Turbulent (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

When the pipe Reynold's number is 6000, the flow is generally (A) Viscous(B) Laminar(C) Turbulent(D) Transition

Description : When the pipe Reynold's number is 6000, the flow is generally (A) Viscous (B) Laminar (C) Turbulent (D) Transition

Last Answer : (C) Turbulent

Transition from laminar flow to turbulent flow in fluid flow through a pipe does not depend upon the (A) Length of the pipe (B) Diameter of the pipe (C) Density of the fluid (D) Velocity of the fluid

Description : Transition from laminar flow to turbulent flow in fluid flow through a pipe does not depend upon the (A) Length of the pipe (B) Diameter of the pipe (C) Density of the fluid (D) Velocity of the fluid

Last Answer : (A) Length of the pipe

Pick out the wrong statement: (A) Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer (B) Blowers develop a maximum pressure of 2 atmospheres (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads (D) Fanning friction factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number

Description : Pick out the wrong statement: (A) Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer (B) Blowers develop a maximum pressure of 2 atmospheres ( ... factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number

Last Answer : (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads

Isothermal turbulent flow of a fluid results in decrease of its pressure, which depends on the (A) Wall roughness (B) Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Isothermal turbulent flow of a fluid results in decrease of its pressure, which depends on the (A) Wall roughness (B) Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of (A) Grashoff number (B) Grashoff number & Reynolds number (C) Reynolds number (D) Grashoff number & Prandtl number

Description : Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of (A) Grashoff number (B) Grashoff number & Reynolds number (C) Reynolds number (D) Grashoff number & Prandtl number

Last Answer : Option D

Fanning friction factor for laminar flow of fluid in a circular pipe is (A) Not a function of the roughness of pipe wall (B) Inversely proportional to Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Fanning friction factor for laminar flow of fluid in a circular pipe is (A) Not a function of the roughness of pipe wall (B) Inversely proportional to Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Which of the fluid forces are not considered in the Reynold's equation of flow? (A) Viscous forces (B) Turbulent forces (C) Pressure forces (D) Compressibility forces

Description : Which of the fluid forces are not considered in the Reynold's equation of flow? (A) Viscous forces (B) Turbulent forces (C) Pressure forces (D) Compressibility forces

Last Answer : (D) Compressibility forces

Pick out the wrong statement. (A) The form drag is dependent upon the occurrence of a wake (B) The shear stress at any given cross-section of a pipe for steady flow (either laminar or turbulent) varies linearly as the radial distance (C) An ideal fluid is the one, which has negligible surface tension and obeys the Newton's law of viscosity (D) Existence of the boundary layer in fluid flow is because of viscosity of the fluid

Description : Pick out the wrong statement. (A) The form drag is dependent upon the occurrence of a wake (B) The shear stress at any given cross-section of a pipe for steady flow (either laminar or turbulent ... of viscosity (D) Existence of the boundary layer in fluid flow is because of viscosity of the fluid

Last Answer : (C) An ideal fluid is the one, which has negligible surface tension and obeys the Newton's law of viscosity

The friction factor for turbulent flow in a hydraulically smooth pipe (A) Depends only on Reynolds number (B) Does not depend on Reynolds number (C) Depends on the roughness (D) None of these

Description : The friction factor for turbulent flow in a hydraulically smooth pipe (A) Depends only on Reynolds number (B) Does not depend on Reynolds number (C) Depends on the roughness (D) None of these

Last Answer : (A) Depends only on Reynolds number

The distribution of shear stress in a stream of fluid in a circular tube is(A) Linear with radius for turbulent flow only(B) Linear with radius for laminar flow only(C) Linear with radius for both laminar & turbulent flow(D) Parabolic with radius for both laminar & turbulent flow

Description : The distribution of shear stress in a stream of fluid in a circular tube is (A) Linear with radius for turbulent flow only (B) Linear with radius for laminar flow only (C) Linear with radius for both laminar & turbulent flow (D) Parabolic with radius for both laminar & turbulent flow

Last Answer : (C) Linear with radius for both laminar & turbulent flow

Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as (A) Re0.5, Re0.8 (B) Re0.8, Re-0.5 (C) Re0.8, Re0.5 (D) Re-0.8, Re0.5

Description : Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as (A) Re0.5, Re0.8 (B) Re0.8, Re-0.5 (C) Re0.8, Re0.5 (D) Re-0.8, Re0.5

Last Answer : (C) Re0.8, Re0.5

Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as (A) Gr0.25, Gr (B) Gr0.25, Gr0.33 (C) Gr, Gr0.25 (D) Gr0.33, Gr0.25

Description : Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as (A) Gr0.25, Gr (B) Gr0.25, Gr0.33 (C) Gr, Gr0.25 (D) Gr0.33, Gr0.25

Last Answer : Option A

Location of vena-contracta in an orificemeter does not depend upon the (A) Type of orifice (B) Density, viscosity & compressibility of the fluid (C) Ratio of pipe diameter to orifice diameter (D) Pipe roughness

Description : Location of vena-contracta in an orificemeter does not depend upon the (A) Type of orifice (B) Density, viscosity & compressibility of the fluid (C) Ratio of pipe diameter to orifice diameter (D) Pipe roughness

Last Answer : (A) Type of orifice

Transition curves are introduced at either end of a circular curve, to obtain (A) Gradually decrease of curvature from zero at the tangent point to the specified quantity at the junction of the transition curve with main curve (B) Gradual increase of super-elevation from zero at the tangent point to the specified amount at the junction of the transition curve with main curve (C) Gradual change of gradient from zero at the tangent point to the specified amount at the junction of the transition curve with main curve (D) None of these

Description : Transition curves are introduced at either end of a circular curve, to obtain (A) Gradually decrease of curvature from zero at the tangent point to the specified quantity at the junction of the ... specified amount at the junction of the transition curve with main curve (D) None of these

Last Answer : (B) Gradual increase of super-elevation from zero at the tangent point to the specified amount at the junction of the transition curve with main curve

For laminar flow of a shear thinning liquid in a pipe, if the volumetric flow rate is doubled, the pressure gradient will increase by a factor of (A) 2 (B) < 2 (C) > 2 (D) 1/2

Description : For laminar flow of a shear thinning liquid in a pipe, if the volumetric flow rate is doubled, the pressure gradient will increase by a factor of (A) 2 (B) < 2 (C) > 2 (D) 1/2

Last Answer : (A) 2

In a fully turbulent flow (Re > 10 5 ) in a pipe of diameter 'd', for a constant pressure gradient, the dependence of volumetric flow rate of an incompressible fluid is (A) d(B) d2(C) d2.5(D) d

Description : In a fully turbulent flow (Re > 10 5 ) in a pipe of diameter 'd', for a constant pressure gradient, the dependence of volumetric flow rate of an incompressible fluid is (A) d (B) d 2 (C) d 2.5 (D) d

Last Answer : (C) d 2.5

In case of a plate and frame filter press, filtrate flow through the cake follows __________ flow. (A) Plug (B) Turbulent (C) Laminar (D) None of these

Description : In case of a plate and frame filter press, filtrate flow through the cake follows __________ flow. (A) Plug (B) Turbulent (C) Laminar (D) None of these

Last Answer : (C) Laminar

A straight line is obtained on plotting reciprocal of filtration rate vs. the volume of filtrate for __________ flow of filtrate. (A) Compressible cakes and laminar (B) Incompressible cake and laminar (C) Compressible cake and turbulent (D) Incompressible cake and turbulent

Description : A straight line is obtained on plotting reciprocal of filtration rate vs. the volume of filtrate for __________ flow of filtrate. (A) Compressible cakes and laminar (B) Incompressible cake and laminar (C) Compressible cake and turbulent (D) Incompressible cake and turbulent

Last Answer : (B) Incompressible cake and laminar

Maximum heat transfer rate is achieved in __________ flow. (A) Co-current (B) Counter-current (C) Turbulent (D) Laminar

Description : Maximum heat transfer rate is achieved in __________ flow. (A) Co-current (B) Counter-current (C) Turbulent (D) Laminar

Last Answer : (C) Turbulen

The Graetz number is concerned with the (A) Mass transfer between a gas and a liquid (B) Absorption with chemical reaction (C) Heat transfer in turbulent flow (D) Heat transfer in laminar flow

Description : The Graetz number is concerned with the (A) Mass transfer between a gas and a liquid (B) Absorption with chemical reaction (C) Heat transfer in turbulent flow (D) Heat transfer in laminar flow

Last Answer : (D) Heat transfer in laminar flow

Dittus-Boelter equation used for the determination of heat transfer co￾efficient is valid (A) For fluids in laminar flow (B) For fluids in turbulent flow (C) When Grashoff number is very important (D) For liquid metals

Description : Dittus-Boelter equation used for the determination of heat transfer co￾efficient is valid (A) For fluids in laminar flow (B) For fluids in turbulent flow (C) When Grashoff number is very important (D) For liquid metals

Last Answer : (B) For fluids in turbulent flow

Bernoulli's equation describes the (A) Mechanical energy balance in potential flow (B) Kinetic energy balance in laminar flow (C) Mechanical energy balance in turbulent flow (D) Mechanical energy balance in boundary layer

Description : Bernoulli's equation describes the (A) Mechanical energy balance in potential flow (B) Kinetic energy balance in laminar flow (C) Mechanical energy balance in turbulent flow (D) Mechanical energy balance in boundary layer

Last Answer : (A) Mechanical energy balance in potential flow

Pick out the correct statement. (A) A forced vortex occurs when fluid rotates as a solid about an axis (B) In laminar flow, Newton's law of viscosity does not apply (C) A free vortex occurs, when fluid rotates as a solid (D) In turbulent flow, there are neither cross-currents nor eddies

Description : Pick out the correct statement. (A) A forced vortex occurs when fluid rotates as a solid about an axis (B) In laminar flow, Newton's law of viscosity does not apply (C) A free vortex occurs, when fluid rotates as a solid (D) In turbulent flow, there are neither cross-currents nor eddies

Last Answer : (A) A forced vortex occurs when fluid rotates as a solid about an axis

f = 16/NRe , is valid for (A) Turbulent flow (B) Laminar flow through an open channel(C) Steady flow(D) None of these

Description : f = 16/NRe , is valid for (A) Turbulent flow (B) Laminar flow through an open channel (C) Steady flow (D) None of these

Last Answer : (D) None of these

In turbulent flow, the (A) Fluid particles move in an orderly manner (B) Momentum transfer is on molecular scale only (C) Shear stress is caused more effectively by cohesion than momentum transfer (D) Shear stresses are generally larger than in a similar laminar flow

Description : In turbulent flow, the (A) Fluid particles move in an orderly manner (B) Momentum transfer is on molecular scale only (C) Shear stress is caused more effectively by cohesion than momentum transfer (D) Shear stresses are generally larger than in a similar laminar flow

Last Answer : (D) Shear stresses are generally larger than in a similar laminar flow

Pick out the wrong statement. (A) A fluid mass is free from shearing forces, when it is made to rotate with a uniform velocity(B) Newton's law of viscosity is not applicable to the turbulent flow of fluidwith linear velocity distribution(C) Laminar flow of viscous liquids is involved in the lubrication of varioustypes of bearings(D) Rise of water in capillary tubes reduces with the increasing diameter ofcapillary tubes

Description : Pick out the wrong statement. (A) A fluid mass is free from shearing forces, when it is made to rotate with a uniform velocit (B) Newton's law of viscosity is not applicable to the ... types of bearings (D) Rise of water in capillary tubes reduces with the increasing diameter of capillary tubes

Last Answer : (B) Newton's law of viscosity is not applicable to the turbulent flow of fluid with linear velocity distribution

Consider the following statements in respect of steady laminar flow through a circular pipe: 1. Shear stress is zero on the central axis of the pipe 2. Discharge varies directly with the viscosity of the fluid 3. Velocity is maximum at the centre of the pipe. 4. Hydraulic gradient varies as the square of the mean velocity of flow. Which of these statements are correct? (a) 1, 2 , 3 & 4 (b) 1 & 3 only (c) 2 & 4 only (d)3 & 4 only

Description : Consider the following statements in respect of steady laminar flow through a circular pipe: 1. Shear stress is zero on the central axis of the pipe 2. Discharge varies directly with the viscosity of the fluid 3. Velocity is maximum at the ... 2 , 3 & 4 (b) 1 & 3 only (c) 2 & 4 only (d)3 & 4 only

Last Answer : (b) 1 & 3 only

In the complete turbulence zone (in rough pipes), the (A) Rough and smooth pipes have the same friction factor (B) Laminar film covers the roughness projections (C) Friction factor depends upon NRe only (D) Friction factor is independent of the relative roughness

Description : In the complete turbulence zone (in rough pipes), the (A) Rough and smooth pipes have the same friction factor (B) Laminar film covers the roughness projections (C) Friction factor depends upon NRe only (D) Friction factor is independent of the relative roughness

Last Answer : (D) Friction factor is independent of the relative roughness

A flow in which the viscosity of fluid is dominating over the inertia force is called (A) Steady flow (B) Unsteady flow (C) Laminar flow (D) Turbulent flow

Description : A flow in which the viscosity of fluid is dominating over the inertia force is called (A) Steady flow (B) Unsteady flow (C) Laminar flow (D) Turbulent flow

Last Answer : Answer: Option C

General energy equation holds for (A) Steady flow (B) Turbulent flow (C) Laminar flow (D) Non-uniform flow

Description : General energy equation holds for (A) Steady flow (B) Turbulent flow (C) Laminar flow (D) Non-uniform flow

Last Answer : Answer: Option D

A large Reynold number is indication of (A) Smooth and streamline flow (B) Laminar flow (C) Steady flow (D) Highly turbulent flow

Description : A large Reynold number is indication of (A) Smooth and streamline flow (B) Laminar flow (C) Steady flow (D) Highly turbulent flow

Last Answer : Answer: Option D

The velocity at which the flow changes from laminar flow to turbulent flow is called (A) Critical velocity (B) Velocity of approach (C) Sub-sonic velocity (D) Super-sonic velocity

Description : The velocity at which the flow changes from laminar flow to turbulent flow is called (A) Critical velocity (B) Velocity of approach (C) Sub-sonic velocity (D) Super-sonic velocity

Last Answer : Answer: Option A

The flow in a pipe is neither laminar nor turbulent when Reynold number is (A) Less than 2000 (B) Between 2000 and 2800 (C) More than 2800 (D) None of these

Description : The flow in a pipe is neither laminar nor turbulent when Reynold number is (A) Less than 2000 (B) Between 2000 and 2800 (C) More than 2800 (D) None of these

Last Answer : Answer: Option B

Define : (i) Laminar flow (ii) Turbulent flow

Description : Define : (i) Laminar flow (ii) Turbulent flow

Last Answer : Laminar flow: - 1. Laminar flow occurs when the fluid flows in infinitesimal parallel layers with no disruption between them. For laminar flow Reynolds number Re < 2300 OR 2. The flow in which ... such a way that its velocity changes irregularly, such type of flow is known as turbulent flow. 

Compare i) Steady and uniform flow ii) Laminar and turbulent flow

Description : Compare i) Steady and uniform flow ii) Laminar and turbulent flow

Last Answer : Steady flow:- The flow is said to be steady when the flow characteristics, such as velocity, pressure, density and temperature do not change with time. Water flowing through a tap at a constant rate is an ... called as turbulent flow. e.g. The flow of river at the time of flood is turbulent flow.

Define laminar flow and turbulent flow.

Description : Define laminar flow and turbulent flow.

Last Answer : Laminar flow : When a fluid flowing through the pipe at different speeds (fast at center and slow at edges), and the fluid particles move in layers with one layer sliding over the adjacent ... successive cross sections, then this flow is called as turbulent flow. Reynolds no is greater than 4000 

Asymptotic conditions is reached, when for a fluid flowing in laminar flow through a long tube (A) Exit-fluid temperature > wall temperature (B) Exit fluid temperature < wall temperature (C) Exit fluid temperature = wall temperature (D) Graetz number > 100

Description : Asymptotic conditions is reached, when for a fluid flowing in laminar flow through a long tube (A) Exit-fluid temperature > wall temperature (B) Exit fluid temperature < wall temperature (C) Exit fluid temperature = wall temperature (D) Graetz number > 100

Last Answer : (C) Exit fluid temperature = wall temperature

The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are (A) Re.Gz (B) Nu, Pr (C) Nu, Pr, Re (D) Nu, Gz

Description : The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are (A) Re.Gz (B) Nu, Pr (C) Nu, Pr, Re (D) Nu, Gz

Last Answer : (D) Nu, Gz

Pick out the wrong statement. (A) Momentum transfer in laminar flow results from velocity gradient (B) A fluid in equilibrium is not free from shear stress (C) The viscosity of a non-Newtonian fluid is a function of temperature only (D) Both (B) and (C)

Description : Pick out the wrong statement. (A) Momentum transfer in laminar flow results from velocity gradient (B) A fluid in equilibrium is not free from shear stress (C) The viscosity of a non-Newtonian fluid is a function of temperature only (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

Momentum transfer in laminar flow of fluids results due to the (A) Viscosity (B) Density (C) Velocity gradient (D) None of these

Description : Momentum transfer in laminar flow of fluids results due to the (A) Viscosity (B) Density (C) Velocity gradient (D) None of these

Last Answer : (C) Velocity gradient

A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer co￾efficient for turbulent flow conditions is proportional to (A) d 0.8 (B) d -0.2 (C) d -1 (D) d -1.8

Description : A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer co￾efficient for turbulent flow conditions is proportional to (A) d 0.8 (B) d -0.2 (C) d -1 (D) d -1.8

Last Answer : (B) d -0.2

essure drop (Δp) for a fluid flowing in turbulent flow through a pipe is a function of velocity (V) as (A) V1.8 (B) V-0.2 (C) V2.7 (D) V

Description : essure drop (Δp) for a fluid flowing in turbulent flow through a pipe is a function of velocity (V) as (A) V1.8 (B) V-0.2 (C) V2.7 (D) V

Last Answer : (D) V

Pressure drag does not depend upon the(A) Roughness of surface of the body (B) Pressure of main flow only (C) Length of the body in flow direction (D) All (A), (B) and (C)

Description : Pressure drag does not depend upon the (A) Roughness of surface of the body (B) Pressure of main flow only (C) Length of the body in flow direction (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)