PE Fluid Mechanics - Professional Engineer Exam Prep, Questions & Answers
What is gauge pressure? Refers to values of pressure measured relative to local atmosphere, can be
negative.
What are the standard atmosphere pressures in kPa and 101 kPa, 14.7 psi
psi?
What is specific weight and how is it calculated? Weight per unit of volume, density times gravity
What is Specific Gravity? Ratio of density or specific weight of a substance to that of water.
What is the piezometric head? Pressure/Specific Weight + z
What is a manometer and how does it work? Columns of liquid used to measure pressure by balancing the weight of the liquid
column against an applied pressure, using the height difference to calculate the
pressure.
What is viscosity? What does a high viscosity fluid The rate of deformation of a fluid under shear stress, higher viscosity fluids
experience? experience smaller deformations
How to get velocity from radial velocity? V = WR, where W is in Rad / S, and R is the radius of the inner circle
The torque required to rotate an inner cyclone is linearly Viscocity
proportional to what?
What is a viscometer? A device that can be used to measure viscosity using two flat plates sandwiched
with a fluid inbetween
What is the no slip condition? A fluid being sheared between two cylinders will stick to both.
What is a Newtonian fluid? The shear stress is directly proportional to the velocity gradient / shear strain rate.
What are reyne and poise units of? Dynamic Viscosity
What are the units of dynamic viscosity? Length squared over time
What is the bulk modulus of elasticity? K, gives the relative change in volume for a given change in pressure applied to a
fluid at a constant temperature T
Stuvia 2026-2027 | Latest Version
, PE Fluid Mechanics - Professional Engineer Exam Prep, Questions & Answers
What is the compressibility of a fluid equal to? Inverse of the bulk modulus of elasticity
Explain how bouyancy forces work Resultant force acting on a body that's submerged, since pressure increases with
depth, the pressure forces acting from below are larger than the ones from above,
resulting in a net upward force.
What is the force of bouyancy equal to? Specific weight of fluid times the volume of the fluid displaced by the body
What is kinematic viscosity? Dynamic viscosity over density
What is the difference between laminar and turbulent flow? In Laminar Flow there is not significant mixing of fluid particles, in turbulent flow
quantities such as velocity and pressure show random fluctuations.
What number should you use to determine if a flow is Reynolds
laminar or turbulent?
What is incompressible flow? What states of matter can Where the density of each particle remains relatively constant. For most purpose
achieve this? liquid flors are incompressible, gas flows can also be incompressible but not always.
At what Mach number is a flow subsonic and supersonic? Less then 1 is subsonic, greater then 1 is supersonic.
What are the equations for velocity, and pressure, and V^2/2g + Pressure/Specific Weight + z = Total Head
elevation head? What do they make up when added
together?
What is the static, stagnation, and hydrostatic pressures? P is the static, P + density times V^ is the stagnation, specific weight times z is
What do they make up? the hydrostatic, added together they are the total pressure
The Bernoulli equation can be used on many steady flow Viscous and compressibility effects are importantl
equations except when...
What is the conservation of mass equation if it involves a A1V1 = A2V2
fluid at a steady flow and constant density?
What to search for to get the Bernoulli equations for a Extended
turbine and pump?
What is the equation for fluid power and what is another W = Q times the change in pressure, theoretical
term for it?
What is brake power and what is the equation to obtain it The power the motor supplies to the pump,
from the pump power? W = Wfluid/npump
Stuvia 2026-2027 | Latest Version
What is gauge pressure? Refers to values of pressure measured relative to local atmosphere, can be
negative.
What are the standard atmosphere pressures in kPa and 101 kPa, 14.7 psi
psi?
What is specific weight and how is it calculated? Weight per unit of volume, density times gravity
What is Specific Gravity? Ratio of density or specific weight of a substance to that of water.
What is the piezometric head? Pressure/Specific Weight + z
What is a manometer and how does it work? Columns of liquid used to measure pressure by balancing the weight of the liquid
column against an applied pressure, using the height difference to calculate the
pressure.
What is viscosity? What does a high viscosity fluid The rate of deformation of a fluid under shear stress, higher viscosity fluids
experience? experience smaller deformations
How to get velocity from radial velocity? V = WR, where W is in Rad / S, and R is the radius of the inner circle
The torque required to rotate an inner cyclone is linearly Viscocity
proportional to what?
What is a viscometer? A device that can be used to measure viscosity using two flat plates sandwiched
with a fluid inbetween
What is the no slip condition? A fluid being sheared between two cylinders will stick to both.
What is a Newtonian fluid? The shear stress is directly proportional to the velocity gradient / shear strain rate.
What are reyne and poise units of? Dynamic Viscosity
What are the units of dynamic viscosity? Length squared over time
What is the bulk modulus of elasticity? K, gives the relative change in volume for a given change in pressure applied to a
fluid at a constant temperature T
Stuvia 2026-2027 | Latest Version
, PE Fluid Mechanics - Professional Engineer Exam Prep, Questions & Answers
What is the compressibility of a fluid equal to? Inverse of the bulk modulus of elasticity
Explain how bouyancy forces work Resultant force acting on a body that's submerged, since pressure increases with
depth, the pressure forces acting from below are larger than the ones from above,
resulting in a net upward force.
What is the force of bouyancy equal to? Specific weight of fluid times the volume of the fluid displaced by the body
What is kinematic viscosity? Dynamic viscosity over density
What is the difference between laminar and turbulent flow? In Laminar Flow there is not significant mixing of fluid particles, in turbulent flow
quantities such as velocity and pressure show random fluctuations.
What number should you use to determine if a flow is Reynolds
laminar or turbulent?
What is incompressible flow? What states of matter can Where the density of each particle remains relatively constant. For most purpose
achieve this? liquid flors are incompressible, gas flows can also be incompressible but not always.
At what Mach number is a flow subsonic and supersonic? Less then 1 is subsonic, greater then 1 is supersonic.
What are the equations for velocity, and pressure, and V^2/2g + Pressure/Specific Weight + z = Total Head
elevation head? What do they make up when added
together?
What is the static, stagnation, and hydrostatic pressures? P is the static, P + density times V^ is the stagnation, specific weight times z is
What do they make up? the hydrostatic, added together they are the total pressure
The Bernoulli equation can be used on many steady flow Viscous and compressibility effects are importantl
equations except when...
What is the conservation of mass equation if it involves a A1V1 = A2V2
fluid at a steady flow and constant density?
What to search for to get the Bernoulli equations for a Extended
turbine and pump?
What is the equation for fluid power and what is another W = Q times the change in pressure, theoretical
term for it?
What is brake power and what is the equation to obtain it The power the motor supplies to the pump,
from the pump power? W = Wfluid/npump
Stuvia 2026-2027 | Latest Version
