Aerodynamic noise resulting from turbulent gas flow is the most prevalent source of valve noise in fluid flow control. It is caused due to (A) Reynold stresses (B) Shear forces (C) Both (A) & (B) (D) Neither (A) nor (B)

Aerodynamic noise resulting from turbulent gas flow is the most
prevalent source of valve noise in fluid flow control. It is caused due to
(A) Reynold stresses
(B) Shear forces
(C) Both (A) & (B)
(D) Neither (A) nor (B)
by

1 Answer

Answer :

(C) Both (A) & (B)
by

Related questions

Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation (B) Cavitation may be caused due to boiling of liquid by decreasing the pressure resulting in formation & collapse of vapor cavities (C) Cavitation begins at higher static pressure and lower velocity in larger diameter pipelines resulting in audible noise(D) Large scale cavitation cannot damage pipeline, restrict fluid flow anddamage steam turbine blades

Description : Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation ... (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades

Last Answer : (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades

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

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

. In case of turbulent flow of fluid through a circular pipe, the (A) Mean flow velocity is about 0.5 times the maximum velocity (B) Velocity profile becomes flatter and flatter with increasing Reynolds number (C) Point of maximum instability exists at a distance of 2r/3 from the pipe wall (r = pipe radius) (D) Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more

Description : . In case of turbulent flow of fluid through a circular pipe, the (A) Mean flow velocity is about 0.5 times the maximum velocity (B) Velocity profile becomes flatter and flatter with ... , shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more

Last Answer : (D) Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more

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)

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

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

Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan (A) With greater number of blades (B) Of increased diameter (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan (A) With greater ... (B) Of increased diameter (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Pick out the wrong statement. (A) Surface tension of a liquid is because of the difference in magnitude of adhesive & cohesive forces(B) A hydrometer used for the determination of specific gravities of liquidsworks on the principle of buoyant forces(C) In case of unsteady fluid flow, the velocity at any given point does notchange with time(D) Turbulent fluid flow is characterised by the rapid fluctuation ofinstantaneous pressure & velocity at a poin

Description : Pick out the wrong statement. (A) Surface tension of a liquid is because of the difference in magnitude of adhesive & cohesive forces (B) A hydrometer used for the determination of ... Turbulent fluid flow is characterised by the rapid fluctuation of instantaneous pressure & velocity at a poin

Last Answer : (C) In case of unsteady fluid flow, the velocity at any given point does not change with time

The rate of shear versus the shear stress curves are time dependent for __________ fluid. (A) Thixotropic (B) Rheopectic (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The rate of shear versus the shear stress curves are time dependent for __________ fluid. (A) Thixotropic (B) Rheopectic (C) Both (A) & (B) (D) Neither (A) nor (B)

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

The flow in a pipe is 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 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 C

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

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

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) 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

Fluid resistance to shear depends upon its (A) Rate of transfer of molecular momentum (B) Cohesion (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Fluid resistance to shear depends upon its (A) Rate of transfer of molecular momentum (B) Cohesion (C) Both (A) and (B) (D) Neither (A) nor (B)

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

. In magnetic flow meters, voltage generation is (A) Due to the motion of conducting fluid through an externally generated uniform field (B) Proportional to the fluid velocity (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : . In magnetic flow meters, voltage generation is (A) Due to the motion of conducting fluid through an externally generated uniform field (B) Proportional to the fluid velocity (C) Both (A) and (B) (D) Neither (A) nor (B)

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

The effect of solid boundary on the fluid flow is confined to the boundary layer, except for fluids (A) Having high viscosities (B) Moving at low velocities (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The effect of solid boundary on the fluid flow is confined to the boundary layer, except for fluids (A) Having high viscosities (B) Moving at low velocities (C) Both (A) & (B) (D) Neither (A) nor (B)

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

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)

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

Water hammer in a pipeline results from the (A) Bursting of pipelines due to closure by a valve (B) Rapid pressure change due to a rapid change in the rate of flow (C) Pressure increase due to closure of a valve resulting in decrease in rate of flow (D) None of these

Description : Water hammer in a pipeline results from the (A) Bursting of pipelines due to closure by a valve (B) Rapid pressure change due to a rapid change in the rate of flow (C) Pressure increase due to closure of a valve resulting in decrease in rate of flow (D) None of these

Last Answer : (B) Rapid pressure change due to a rapid change in the rate of flow

Fanning friction factor equation applies to the __________ fluid flow. (A) Non-isothermal condition of (B) Compressible (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Fanning friction factor equation applies to the __________ fluid flow. (A) Non-isothermal condition of (B) Compressible (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (D) Neither (A) nor (B)

In case of a P.F.R., there (A) May be lateral mixing of fluid (B) Should not be any mixing along the flow path (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : In case of a P.F.R., there (A) May be lateral mixing of fluid (B) Should not be any mixing along the flow path (C) Both (A) and (B) (D) Neither (A) nor (B)

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

Toothed roll crushers achieve size reduction by (A) Tearing (shear) and compression (B) Impact and attrition (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Toothed roll crushers achieve size reduction by (A) Tearing (shear) and compression (B) Impact and attrition (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Which of the following fluid forces are not considered in the Navier￾Stoke's equation? (A) Gravity forces (B) Viscous forces (C) Pressure forces (D) Turbulent forces

Description : Which of the following fluid forces are not considered in the Navier￾Stoke's equation? (A) Gravity forces (B) Viscous forces (C) Pressure forces (D) Turbulent forces

Last Answer : (D) Turbulent forces

Bernoulli's equation for fluid flow is derived following certain assumptions. Out of the assumptions listed below, which set of assumptions is used in derivation of Bernoulli's equation? A. Fluid flow is frictionless & irrotational. B. Fluid flow is steady. C. Fluid flow is uniform & turbulent. D. Fluid is compressible. E. Fluid is incompressible. (A) A, C, D (B) B, D, E (C) A, B, E (D) A, D, E

Description : Bernoulli's equation for fluid flow is derived following certain assumptions. Out of the assumptions listed below, which set of assumptions is used in derivation of Bernoulli's equation? A. Fluid flow is frictionless & irrotational. B. Fluid flow is ... A, C, D (B) B, D, E (C) A, B, E (D) A, D, E

Last Answer : (C) A, B, E

The internal energy of an incompressible fluid depends upon its (A) Pressure (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The internal energy of an incompressible fluid depends upon its (A) Pressure (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (B) Temperature

The ratio of inertial forces to viscous forces is called the __________ number. (A) Weber (B) Mach (C) Froude (D) Reynold

Description : The ratio of inertial forces to viscous forces is called the __________ number. (A) Weber (B) Mach (C) Froude (D) Reynold

Last Answer : (D) Reynold

The ratio of pressure forces to inertial forces is called the __________ number. (A) Froude (B) Euler (C) Reynold (D) Mach

Description : The ratio of pressure forces to inertial forces is called the __________ number. (A) Froude (B) Euler (C) Reynold (D) Mach

Last Answer : (B) Euler

. A fluid which has a linear relationship between the magnitude of applied shear-stress and the resulting rate of deformation is called a/an __________ fluid. (A) Newtonian (B) Non-Newtonian (C) Ideal (D) Incompressible

Description : . A fluid which has a linear relationship between the magnitude of applied shear-stress and the resulting rate of deformation is called a/an __________ fluid. (A) Newtonian (B) Non-Newtonian (C) Ideal (D) Incompressible

Last Answer : (A) Newtonian

In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said to have the same hydraulic roughness, when they have equal values of (A) Relative roughness (B) Absolute roughness (C) Friction co-efficient for flows at equal Reynold number (D) All (A), (B) & (C)

Description : In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said ... co-efficient for flows at equal Reynold number (D) All (A), (B) & (C)

Last Answer : (C) Friction co-efficient for flows at equal Reynold number

The fluid forces considered in the Navier Stokes equation are (A) Gravity, pressure and viscous (B) Gravity, pressure and turbulent (C) Pressure, viscous and turbulent (D) Gravity, viscous and turbulent

Description : The fluid forces considered in the Navier Stokes equation are (A) Gravity, pressure and viscous (B) Gravity, pressure and turbulent (C) Pressure, viscous and turbulent (D) Gravity, viscous and turbulent

Last Answer : Answer: Option A

Pick out the wrong statement. (A) Fluid movement under the influence of buoyant forces resulting from change in density takes place in case of natural convection (B) The ratio NNu /NRe . Npr is called the Stanton number (C) The Peclet number is a measure of the ratio of energy transport by convection to that by conduction (D) The Colburn jH factor for heat transfer is given by Nst Npr

Description : Pick out the wrong statement. (A) Fluid movement under the influence of buoyant forces resulting from change in density takes place in case of natural convection (B) The ratio NNu /NRe . Npr is ... convection to that by conduction (D) The Colburn jH factor for heat transfer is given by Nst Npr

Last Answer : (D) The Colburn jH factor for heat transfer is given by Nst Npr

In a static fluid (A) Resistance to shear stress is small (B) Fluid pressure is zero (C) Linear deformation is small (D) Only normal stresses can exist

Description : In a static fluid (A) Resistance to shear stress is small (B) Fluid pressure is zero (C) Linear deformation is small (D) Only normal stresses can exist

Last Answer : Answer: Option D

Water hammer is caused, when water flowing in a pipe is suddenly brought to rest by closing the valve. The extent of pressure thus produced due to water hammer depends on the (A) Pipe length (B) Fluid velocity in the pipe (C) Time taken to close the valve (D) All (A), (B) and (C)

Description : Water hammer is caused, when water flowing in a pipe is suddenly brought to rest by closing the valve. The extent of pressure thus produced due to water hammer depends on the (A) Pipe length (B) Fluid velocity in the pipe (C) Time taken to close the valve (D) All (A), (B) and (C)

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

The loss of head due to friction in a pipe of uniform diameter in which a viscous flow is taking place, is (where RN = Reynold number) (A) 1/RN (B) 4/RN (C) 16/RN (D) 64/RN

Description : The loss of head due to friction in a pipe of uniform diameter in which a viscous flow is taking place, is (where RN = Reynold number) (A) 1/RN (B) 4/RN (C) 16/RN (D) 64/RN

Last Answer : Answer: Option C

A globe valve is the most suitable for applications, in which (A) Fluid flow control is required (B) Fluid contains dispersed solid particles (C) Valve is required to be either fully open or fully closed (D) One way flow is required

Description : A globe valve is the most suitable for applications, in which (A) Fluid flow control is required (B) Fluid contains dispersed solid particles (C) Valve is required to be either fully open or fully closed (D) One way flow is required

Last Answer : (A) Fluid flow control is required

Stefan's law describes the mass transfer by (A) Diffusion (B) Bulk flow (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'

Description : Stefan's law describes the mass transfer by (A) Diffusion (B) Bulk flow (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'

Last Answer : (C) Both 'a' & 'b'

The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (A) Plug

The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (B) Perfectly mixed

With diminishing cross-sectional area in case of subsonic flow in a converging nozzle, the (A) Velocity increases (B) Pressure decreases (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : With diminishing cross-sectional area in case of subsonic flow in a converging nozzle, the (A) Velocity increases (B) Pressure decreases (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Hydraulic mean depth (Dm) for a circular pipe of diameter 'D' flowing full is 0.25 D. For a circular channel, at Dm = 0.3 D, gives the condition for the maximum (A) Flow rate (B) Mean velocity (C) Both 'a' & 'b' (D) Neither 'a' nor 'b

Description : Hydraulic mean depth (Dm) for a circular pipe of diameter 'D' flowing full is 0.25 D. For a circular channel, at Dm = 0.3 D, gives the condition for the maximum (A) Flow rate (B) Mean velocity (C) Both 'a' & 'b' (D) Neither 'a' nor 'b

Last Answer : (B) Mean velocity

Mass velocity in case of steady flow and through a constant cross￾section conduit is independent of the (A) Temperature (B) Pressure (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Mass velocity in case of steady flow and through a constant cross￾section conduit is independent of the (A) Temperature (B) Pressure (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Signal normally used to study non-ideal flow by stimulus response technique is __________ input. (A) Pulse (B) Step (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Signal normally used to study non-ideal flow by stimulus response technique is __________ input. (A) Pulse (B) Step (C) Both (A) & (B) (D) Neither (A) nor (B)

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

The single parameter model proposed for describing non-ideal flow is the __________ model. (A) Tank in series (B) Dispersion (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The single parameter model proposed for describing non-ideal flow is the __________ model. (A) Tank in series (B) Dispersion (C) Both (A) & (B) (D) Neither (A) nor (B)

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

The effect of friction on the flow of steam through a nozzle is to decrease the __________ of steam. (A) Wetness (B) Mass flow rate (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'

Description : The effect of friction on the flow of steam through a nozzle is to decrease the __________ of steam. (A) Wetness (B) Mass flow rate (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'

Last Answer : (C) Both 'a' & 'b'

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

Navier-Stokes equation is useful in the analysis of __________ fluid flow problems. (A) Non-viscous (B) Viscous (C) Turbulent (D) Rotational

Description : Navier-Stokes equation is useful in the analysis of __________ fluid flow problems. (A) Non-viscous (B) Viscous (C) Turbulent (D) Rotational

Last Answer : (B) Viscous

In which type of fluid flow, the velocity of flow of fluid changes from point to point in the fluid at any instant? (A) Rotational (B) Unsteady (C) Turbulent (D) Non-uniform

Description : In which type of fluid flow, the velocity of flow of fluid changes from point to point in the fluid at any instant? (A) Rotational (B) Unsteady (C) Turbulent (D) Non-uniform

Last Answer : (D) Non-uniform

Pick out the wrong statement pertaining to fluid flow. (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5 (B) The Newtonian fluid velocity in a circular pipe flow is maximum at the centre of the pipe (C) Navier-Stokes equation is applicable to the analysis of viscous flows

Description : Pick out the wrong statement pertaining to fluid flow. (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5 (B) The Newtonian ... at the centre of the pipe (C) Navier-Stokes equation is applicable to the analysis of viscous flows

Last Answer : (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5