inzinerski formuli equations
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8/12/2019 Inzinerski Formuli Equations
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Engineering SoftwareP.O. Box 1180, Germantown, MD 20875
Phone: (301) 540-3605
FAX: (301) 540-3605
E-Mail: info@engineering-4e.com
Web Site: http://www.engineering-4e.com
Engineeri ng Software is pleased to announce the introduction of Free Coursework Materi al.
Engineeri ng SoftwareCoursework Materi alcovers the following area:
Engineering F ormulas
Here are some of the basic engineering formulas/equations related to energy conversion systems:
Continui ty Equation
m = vA
Momentum Equation
F = (vm + pA)out - in
Energy Equation
Q - W = ((h + v2/2 + gh)m)out - in
State Equation for I deal Gas
pv= RT/MW
Perfect Gas
cp= constant
= cp/cv
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I sentropic Compression
T2/T1= (p2/p1)(-1)/
T2/T1= (V1/V2)(-1)
p2/p1= (V1/V2)
Combustion -- F lame Temperature
hreactants= hproducts
CombustionHHV
HHV= hreactants-hproducts
I sentr opic Expansion
T1/T2= (p1/p2)(-1)/
T1/T2= (V2/V1)(-1)
p1/p2= (V2/V1)
Sonic Velocity
vs= (RT/MW)1/2
Mach Number
M= v/vs
I sentropic F low
Tt /T= (1 + M2( - 1)/2)
pt/p= (1 + M2( - 1)/2)/(-1)
ht= (h + v2/2)
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Tt= (T + v2/(2cp))
Thrust
Thrust= vm + (p - pa)A
Cycle Ef fi ciency
Cycle Efficiency= Net Work/Heat
Carnot Cycle Ef fi ciency
Carnot Cycle Efficiency = 1 - Theat rejection/Theat addition
Brayton Cycle Ef fi ciency
Brayton Cycle Efficiency = 1 - 1/(p2/p1)(-1)/
Otto Cycle Ef fi ciency
Compression Ratio = V1/V2
Otto Cycle Efficiency= 1 - 1/Compression Ratio(-1)
Diesel Cycle Ef fi ciency
Compression Ratio (CR) = V1/V2
Cut-Off Ratio (COR) = V3/V2
Diesel Cycle Efficiency =1 - (COR- 1)/(*CR(-1)*(COR - 1))
Fuel Cell
Fuel Cell Efficiency= - (Gout- Gin)/HHV
Heat Rate
Heat Rate = (1/Cycle Efficiency)*3,412
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Physical Properties
For each reaction species, the thermodynamic functions specific heat, enthalpy and entropy asfunctions of temperature are given in the form of least squares coefficients as follows:
Cp/R = A1 + A2T + A3T
2
+ A4T
3
+ A5T
4
H/(R*T) = A1 + A2T/2 + A3T2/3 + A4T
3/4 + A5T
4/5 + A6/T
S/R = A1lnT + A2T + A3T2/2 + A4T
3/3 + A5T
4/4 + A7
or
S/R = A1lnT + A2T + A3T2/2 + A4T
3/3 + A5T
4/4 + A7- lnp
For each species, two sets of coefficients are included for two adjacent temperature intervals, 273
to 1,000 [K] and 1,000 to 5,000 [K]. The data have been constrained to be equal at 1,000 [K].
Also,
U = H - p*v*MW or U = H - R*T
G = H - S*T
and
u = h - p*v or u = h - R*T/MW
g = h - s*T
Legend:
m -- Mass Flow Rate [kg/s]
-- Density [kg/m3]
v -- Velocity [m/s]
A -- Cross Sectional Area [m
2
]
F -- Force [N]
p -- Pressure [N/m2]
q -- Heat [kJ/kg]
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w -- Work [kJ/kg]
g -- Gravitational Acceleration [m/s2]
h -- Height [m]
k -- Kappa [/]
hreactants-- Reactants Enthalpy [kJ/kg]
hproducts-- Products Enthalpy [kJ/kg]
HHV -- Higher Heating Value [Btu/lbm]
vs-- Sonic Velocity [m/s]
M -- Mach Number [/]
Cp-- Specific Heat [kJ/kmol*K]
cp-- Specific Heat [kJ/kg*K]
MW -- Molecular Weight [kg/kmol]
R -- Universal Gas Constant [kJ/kmol*K]
Gas Constant = R/MW [kJ/kg*K]
H -- Enthalpy [kJ/kmol]
h -- Enthalpy [kJ/kg]
T -- Temperature [K]
S -- Entropy [kJ/kmol*K]
s -- Entropy [kJ/kg*K]
p -- Pressure [atm]
U -- Internal Energy [kJ/kmol]
u -- Internal Energy [kJ/kg]
v -- Specific Volume [m3/kg]
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G -- Gibbs Free Energy [kJ/kmol]
g -- Gibbs Free Energy [kJ/kg]
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