So Much Fun!!! Flashcards
(18 cards)
What is the name and formula for the dimensionless parameter relating:
inertia & compressibility
Mach number (Ma)
Ma² = ρV² / B
Ma = V / √(B/ρ)
c (speed of sound waves) = √(B/ρ)
What is the name and formula for the dimensionless parameter relating:
inertia & gravity
Froude number (Fr)
Fr² = ρV² / ρgL = V² / gL
Fr = V / √(gL)
c (speed of gravity waves) = √(gL)
What is the name and formula for the dimensionless parameter relating:
inertia & surface tension
Weber number (We)
We = ρV² / (σ/L) = V²ρL / σ
c (speed of capillary waves) = √(σ / ρL)
What is the name and formula for the dimensionless parameter relating:
inertia & viscosity
Reynolds number (Re)
Re = ρV² / (μV / L) = VρL / μ
What is the name and formula for the dimensionless parameter relating:
pressure change & inertia
Euler number (Eu)
Eu = Δp / ρV²
What is the name and formula for the dimensionless parameter relating:
centrifugal force & inertia
Strouhal number (St)
St = Iω / V
What is the formula for the friction factor (using stagnation pressure as a basis)?
f = D(dp’‘/dx) / ½ρV²
What is the formula for the drag coefficient (using stagnation pressure as a basis)?
C_D = (F_D / A) / ½ρV²
What is the formula for the thrust coefficient (using stagnation pressure as a basis)?
C_T = (F_T / D²) / ½ρV²
What is a formula you can use for torque similarity (using stagnation pressure as a basis)?
(T / L³) / ½ρV²
where T is torque
NOT IN ASSIGNMENTS
What is the formula for the absolute pressure coefficient (using stagnation pressure as a basis)?
p / ½ρV²
What is the formula you can use for flow rate similarity?
Q / VL²
What is the formula you can use for rotational kinematic similarity?
V / ωL
What is the formula to relate:
gravity & surface tension
Which two fundamental dimensionless constants are used?
Gravity: Fr² = V² / gL
Surface tension: We = V²ρL / σ
Fr² / We = (V² / gL) / (V²ρL / σ) = σ / ρgL²
Note that the L can also be H
What is the formula to relate:
gravity & viscosity
Which two fundamental dimensionless constants are used?
Gravity: Fr = V / √(gL)
Viscosity: Re = VρL / μ
Fr / Re = (V / √(gL)) / (VρL / μ) = μ / ρL√(gL)
Fr / Re = μ / ρ√(gL³)
Note that the L can also be H
What is the formula for the discharge coefficient (C_Q)?
C_Q = Q / ωD³
What is the formula for the head coefficient (C_H)?
C_H = gH / ω²D²
What is the formula for the Net Positive Suction Head coefficient (C_NPSH)?
C_NPSH = g(NPSH) / ω²D²
