HGE - FORMULAS

Two formula for Mass Density

ρ = M / V

ρ = P / RT

Two values of Gas Constant, R

R = 1716 (lb-ft / slug-R)

R = 287 (J / kg-K)

Kelvin - Celsius Formula

K = C + 273

Rankine - Fahrenheit Formula

R = F + 460

Celsius - Fahrenheit Formula

C(9/5) = (F-32)

Specific Volume, Vs

Vs = 1 / Rho(p)

Unit Weight / Specific Weight Formula, γ

γ = W / V

γ = ρg

Specific Gravity, s

s = ρ(liquid) / ρ(water)

s = γ(liquid) / γ(water)

Density and Unit Weight of water

ρ = 1.94 slug/ft³

ρ = 1000 kg/m³

γ = 9.81 kN/m³

γ = 62.4 lb/ft³

Viscosity, μ

μ = τ / (dU/dy)

Kinematic Viscosity, ν

ν = μ / ρ

Surface Tension or Pressure inside a droplet, P

P = 4σ / d

Capillary

h = 4σ(cosθ) / γd

Compressibility

β = - (dV / Vi ) / dP

Bulk Modulus of Elasticity

Eb = - dP / (dV / Vi)

Bulk Modulus of Elasticity of Water

Eb = 2.2 GPa

Pressure Disturbance

c = √( Eb / ρ )

Gas Laws Formula

(P1V1) / T1 = (P2V2) / T2

Boyle’s Law & Charle’s Law (Isothermal)

P1V1 = P2V2

V1/T1 = V2/T2

Isentropic Formula

P1(V1)^k = P2(V2)^k

T2/T1 = (P2/P1)^(k-1 / k)

where: T must be expressed in Kelvin

Capillarity Angle of Water-Glass

0 degrees

note: ethyl alcohol - glass is also 0 degrees

Capillarity Angle of Mercury-Glass

140 degrees

Pressure Units

1 atm = 101325 Pa = 760mmHg

1mmHg = 1 torr

1 bar = 100,000 Pa

Formula for Absolute Pressure

Pabs = Pgage + Patm

Common unit of Viscosity

1 poise = 1 dyne*s / cm² = 0.1 Pa-sec

1 stoke = 0.0001 m²

_{1 dyne = 10^-5 N}

Specific Gravity of Mercury

13.60

Specific Gravity of Sea Water

1.03

Specific Gravity of Ice

0.92

Adiabatic Index of Hydrogen

1.4

Adiabatic Index of Argon

5/3

Adiabatic Index of Nitrogen

1.4

Adiabatic Index of Oxygen

1.4

Adiabatic Index of Helium

5/3

1 gallon is equal to how many liters?

1 gallon = 3.785 liters

1 slug is equal to how many kg?

1 slug = 14.59 kg

m³ to ft³ conversion

(1m / 3.28ft)³