BME 331

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A control volume is a fixed, identifiable quantity of mass that is isolated from its surroundings by boundaries.

False

A fluid is said to be static if there is no relative motion between adjacent particles.

False

A fluid satisfies the no-slip condition at a solid boundary regardless of whether it's an inviscid fluid or viscous fluid.

False

A frictionless flow is a viscous flow.

False

A fully-developed flow field in the x-direction means that the pressure is constant in the x-direction

False

A large Reynolds number indicates that the flow is more likely to be laminar.

False

A magnetic force is an example of a surface force.

False

A non-newtonian fluid has linear stress to strain relationship for a given applied shear stress.

False

A streamline is a line joining all of the fluid particles that have passed through a fixed point in the flow field.

False

A two-dimensional stream function need not be constant along a streamline in unsteady flow

False

A viscous fluid satisfies the no-penetration condition at a solid boundary, such as a wall, but an inviscid fluid does not.

False

All fluids are liquids.

False

An incompressible fluid is expressed mathematically as ρ=0

False

An inviscid fluid in a pipe must always satisfy the no-slip condition.

False

An inviscid fluid is one where the viscosity is constant.

False

An inviscid fluid is one where the vorticity is zero.

False

Consider the steady velocity profile shown in figure below for a widening pipe. This flow is also fully-developed flow field, since it is not changing in time.

False

Ducts, nozzles, and diffusers are examples of external flows.

False

Fluid Particle kinematics do not apply to compressible fluids.

False

For an unsteady system, the volume flow rate in must equal the volume flow rate out of a control volume.

False

For two-dimensional streamline coordinates, the positive n-direction points in a direction perpendicular to the flow direction and away from the convex side toward the concave side.

False

For two-dimensional streamline coordinates, the velocity component in the normal direction, Vn, is never zero (except at an inflection point in the curve).

False

Gage pressure can never be negative.

False

Geometric Similarity implies Kinematic similarity

False

Geometric similarity implies dynamic similarity

False

If a flow had friction, the total head (H) of the flow would increase.

False

If a fluid particle is traveling in a circular path, then it must have nonzero vorticity.

False

If a fluid particle is traveling in a straight path, then it must have zero vorticity.

False

If the fluid is incompressible and the flow field is steady, then you can apply the steady Bernoulli equation between any two points on a streamline.

False

If the meter is put in the boundary layer region, it would not rotate indicating that the boundary layer flow is irrotational.

False

If the vorticity meter is placed in the freestream above the boundary layer, then it would begin to rotate indicating that the freestream flow has vorticity present in it.

False

If μ = constant, then the fluid is irrotational.

False

If ρ = constant, then the fluid is irrotational.

False

Incompressible flow fields must have constant density, ρ = constant.

False

Internal flows with viscosity generally have uniform velocity distributions.

False

Kinematic similarity implies dynamic similarity.

False

Pipes with smaller diameters will have less head loss

False

Stoke's Theorem states that the circulation around a closed contour is equal to the total viscosity within it.

False

The Hanquist number is a common dimensionless group, which is defined as the velocity of the flow divided by the speed of sound

False

The Reynolds number is a ratio of pressure forces to viscous forces.

False

The continuity equation is derived from the conservation of momentum.

False

The continuity equation is the essential governing equation needed for studying head loss.

False

The continuity equation only applies to turbulent flows.

False

The continuity equation states that momentum is conserved.

False

The drag coefficient (CD) has units of force.

False

The friction factor is only a function of the Reynold's number for turbulent flow

False

The friction factor is only a function of the pipe roughness for a laminar flow.

False

The kinematic viscosity, ν=μ/ρ, has SI units of kg/m/s.

False

The motion of a fluid particle can be decomposed into four basic components: kinetic energy, acceleration, momentum, and conservation of mass.

False

The static pressure is due to the bulk motion of the fluid

False

The total head loss, Hlt , consists only of losses due to frictional effects in fully developed pipe flow.

False

Turbulent flow in a pipe is expected for Reynolds numbers less than 2300.

False

Under the steady-state flow assumption the continuity equation can be reduced to the equation: gradient V = 0

False

Velocity is an extensive property of a system.

False

Work is an intensive property of a system.

False

f we take the vorticity of the two-dimensional stream function, then it is always zero provided it is twice differentiable in x and y.

False

if delta ρ/delta time = 0, then the density ρ is constant.

False

A benefit of differential analysis is that it can provide detailed information of the flow field (e.g. pressure and velocity distributions)

True

A dimension is a name given to any measurable quantity.

True

A fluid satisfies the no-penetration condition at a solid boundary regardless of whether it's an inviscid fluid or viscous fluid.

True

A main difference between Euler's equations and Navier-Stokes equations is that Euler's equations are used for inviscid flows and Navier-Stokes are used for viscous flows.

True

A normal stress on a static fluid's surface is also known as pressure.

True

A two-dimensional stream function always satisfies the continuity equation provided it is twice differentiable in x and y

True

A two-dimensional stream function is always constant along a streamline in steady flow

True

A uniform flow field is independent of all space variables.

True

An inviscid fluid cannot satisfy the no-slip condition at a solid boundary.

True

An inviscid fluid is one where the viscosity μ = 0.

True

An irrotational flow has zero vorticity.

True

Archimedes's principle states that a body immersed in a fluid is buoyed up with a force equal to the weight of the fluid displaced by the body.

True

Below is a diagram of a boundary layer that has formed over a flat plate. Take the x-axis to run along the edge of the plate with the origin at the leading edge of the plate and the y-axis pointing upward along the page. Imagine putting a vorticity meter in the velocity profile shown in the figure to determine if the flow field has vorticity present. If the vorticity meter is placed in the freestream above the boundary layer, then it would not rotate because there is no vorticity in uniform flow to put a velocity shear on the meter, indicating that the freestream flow is an irrotational flow field.

True

Consider the steady, one dimensional, one directional flow field for which two velocity profiles are shown in the figure below. The net force on a fluid particle in the velocity fully-developed profile shown in figure must be zero.

True

For Newtonian fluids, the constant dynamic viscosity assumption can be applied to isothermal flow fields.

True

For a steady system and an incompressible flow, the volume flow rate in must equal the volume flow rate out of a control volume.

True

For incompressible newtonian fluids, the constant kinematic viscosity assumption can be applied to isothermal flow fields.

True

For two-dimensional streamline coordinates, if the streamlines are circular and the flow is steady, then the normal acceleration component, a_n, always points towards the concave side of the curve

True

Geometric similarity requires that the model and prototype be the same shape, and that all linear dimensions of the model be related to the corresponding dimensions of the prototype by a constant scale factor.

True

Head loss increases with flow rate.

True

Head loss is typically due to friction.

True

If a fluid is assumed to a continuum, the fluid's properties vary smoothly from point to point.

True

If the fluid is incompressible and inviscid, and the flow field steady, then you can apply the steady Bernoulli equation between any two points on a streamline.

True

If the meter is put in the boundary layer region, it would rotate indicating that the boundary layer flow has vorticity present in it.

True

If ρ = constant, then the flow field is incompressible.

True

In order to use the non-dimensionalization technique, you must know all of the governing equations and the boundary conditions for the system.

True

Inertial forces are fictitious forces that resists a change in velocity of an object.

True

Kinematic similarity implies geometric similarity.

True

Kinematic similarity is a necessary, but not sufficient, requirement for dynamic similarity.

True

Mass is an extensive property of a system.

True

Paint is an example of a psuedoplastic in that it is a shear-thinning fluid.

True

Particle angular deformation is related to shearing.

True

Particle linear deformation is related to volumetric strain (compression/expansion).

True

Particle rotation is related to angular velocity and vorticity.

True

Particle translation is related to linear velocity and linear acceleration.

True

Pascal's law states that pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and to the walls of the container.

True

Pipe roughness, e, has units of length.

True

Suppose the Buckingham Pi Theorem approach leads to one equation with one dependent non-dimensional parameter Π1, and two independent parameters, Π2 and Π3. Then, without knowing anything about the function itself, the resulting non-dimensional functional relationship is of the form: Π1=f~(Π2,Π3).

True

The Buckingham Pi Theorem approach can be applied to situations where you don't know the explicit governing equations.

True

The Eulerian (or field) approach to describing fluid motion describes the flow field as a function of space and time.

True

The Moody diagram relates relative pipe roughness, Reynold's number, and the friction factor.

True

The Reynolds number is a ratio of inertial forces to viscous forces.

True

The boundary condition at a free-surface, such as an air-water interface, is the no shear condition: τ = 0.

True

The constant in the steady Bernoulli equation depends on the streamline that you're on (i.e., on the initial condition).

True

The equation g=6z/t2 dimensionally consistent, where t = time, z = distance, and g = acceleration due to gravity.

True

The following form of the continuity equation is expressed in coordinate-free notation gradient V = 0

True

The fundamental units in the SI system corresponding to mass, length, and time are the kilogram, meter, and second.

True

The kinetic energy correction factor, α , is generally close to unity for turbulent flows.

True

The motion of a fluid particle can be decomposed into four basic components: translation, rotation, linear deformation (stretching/contracting), and angular deformation (shearing).

True

The non-dimensionalization technique is most useful when you are able to identify characteristic properties of the flow field.

True

The parameters ρ, V, and L composing the inertia force term are idea candidates for repeated parameters since the inertia force shows up in so many non-dimensional parameters.

True

The specific weight γ can be defined as: γ=g/v where g is gravity and v is the specific volume.

True

The stagnation pressure (sometimes called total pressure) is essentially the sum of the static and dynamic pressures at a given location in the flow field.

True

The vorticity is twice the average angular velocity.

True

Turbulent flow is flow with fluctuating and disorderly motion.

True

Two flows are dynamically similar when the two flows have force distributions such that identical types of forces are parallel and are related in magnitude by a constant scale factor at all corresponding points.

True

Two flows are kinematically similar when the velocities at corresponding points are in the same direction and differ only by a constant scale factor.

True

Under the incompressible fluid assumption (constant density) the continuity equation can be reduced to the equation: gradient V = 0

True

if gradient cross velocity = 0, then the fluid is irrotational.

True

two-dimensional stream function is always constant along a streamline in steady flow

True


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