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{
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{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Chapter 17:Compressible Fluid Flow"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Ex17.2:pg-717"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\n",
" Example 17.2 \n",
"\n",
"\n",
" Mass flow rate of air through diffuser is 59.4200292233 Kg/s\n",
"\n",
" Mach number of leaving air is 0.135\n",
"\n",
" Temperature of leaving air is 71.4290750078 degree celcius\n",
"\n",
" Pressure of leaving air is 0.260471799082 MPa \n",
"\n",
" Net thrust is 51.3284455434 kN\n"
]
}
],
"source": [
"import math\n",
"P1 = 0.18 # Diffuser static pressure in MPa\n",
"R = 0.287 # Gas constant\n",
"T1 = 37 # Static temperature \n",
"P0 = 0.1# Atmospheric pressure in MPa\n",
"A1 = 0.11 # intake area in m**2\n",
"V1 = 267 # Inlet velocity in m/s\n",
"w = (P1*1e3/(R*(T1+273)))*A1*V1 # mass flow rate\n",
"g = 1.4 # Heat capacity ratio\n",
"c1 = math.sqrt(g*R*(T1+273)*1000) # velocity\n",
"M1 = V1/c1 # Mach number\n",
"A1A_ = 1.0570 # A1/A* A* = A_\n",
"P1P01 = 0.68207 # pressure ratio\n",
"T1T01 = 0.89644# Temperature ratio\n",
"F1F_ = 1.0284# Impulse function ratio\n",
"A2A1 = 0.44/0.11 # Area ratio\n",
"A2A_ = A2A1*A1A_# Area ratio\n",
"M2 = 0.135 # Mach number\n",
"P2P02 = 0.987 # Pressure ratio\n",
"T2T02 = 0.996 # Temperature ratio\n",
"F2F_ = 3.46# Impulse function ratio\n",
"P2P1 = P2P02/P1P01 # Pressure ratio\n",
"T2T1 = T2T02/T1T01# Temperature ratio\n",
"F2F1 = F2F_/F1F_ # Impulse function ratio\n",
"P2 = P2P1*P1 # Outlet pressure\n",
"T2 = T2T1*(T1+273) # Outlet temperature\n",
"A2 = A2A1*A1 # Exit area\n",
"F1 = P1*A1*(1+g*M1**2) # Impulse function\n",
"F2 = F2F1*F1 # Impulse function\n",
"Tint = F2-F1 # Internal thrust\n",
"Text = P0*(A2-A1) # External thrust\n",
"NT = Tint - Text # Net thrust\n",
"\n",
"print \"\\n Example 17.2 \\n\"\n",
"print \"\\n Mass flow rate of air through diffuser is \",w ,\" Kg/s\"\n",
"print \"\\n Mach number of leaving air is \",M2\n",
"print \"\\n Temperature of leaving air is \",T2-273 ,\" degree celcius\"\n",
"print \"\\n Pressure of leaving air is \",P2 ,\" MPa \"\n",
"print \"\\n Net thrust is \",NT*1e3 ,\" kN\"\n",
"\n",
"#The answers vary due to round off error\n",
"\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Ex17.3:pg-718"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\n",
" Example 17.3\n",
"\n",
"\n",
" When divergent section act as a nozzle\n",
"\n",
" Maximum flow rate of air is 1.06476372092 kg/s\n",
"\n",
" Static temperature is 183.204 K\n",
"\n",
" Static Pressure is 93.9 kPa\n",
"\n",
" Velocity at the exit from the nozzle is 596.077184351 m/s\n",
"\n",
"\n",
" When divergent section act as a diffuser\n",
"\n",
" Maximum flow rate of air is 1.06476372092 kg/s\n",
"\n",
" Static temperature is 353.232 K\n",
"\n",
" Static Pressure is 936.0 kPa\n",
"\n",
" Velocity at the exit from the nozzle is 116.03411731 m/s\n"
]
}
],
"source": [
"import math\n",
"M2 = 2.197 # Mach number\n",
"P2P0 = 0.0939 # pressure ratio\n",
"T2T0 = 0.5089 # Temperature ratio\n",
"P0 = 1 # Stagnation pressure in MPa \n",
"T0 = 360 # Stagnation temperature in K\n",
"g = 1.4 # Heat capacity ratio\n",
"R = 0.287 # Gas constant\n",
"P2 = P2P0*P0*1e3 # Static Pressure\n",
"T2 = T2T0*T0 # Static temperature\n",
"c2 = math.sqrt(g*R*T2*1000)\n",
"V2 = c2*M2 #velocity at the exit from the nozzle\n",
"# for air\n",
"P_P0 = 0.528 # pressure ratio\n",
"T_T0 = 0.833 # Temperature ratio\n",
"P_ = P_P0*P0*1e3 # Static Pressure\n",
"T_ = T_T0*T0 #Static temperature\n",
"rho_ = P_/(R*T_) # density\n",
"V_ = math.sqrt(g*R*T_*1000) # Velocity at the exit from the nozzle \n",
"At = 500e-06 # throat area\n",
"w = At*V_*rho_# Maximum flow rate of air\n",
"\n",
"print \"\\n Example 17.3\\n\"\n",
"print \"\\n When divergent section act as a nozzle\"\n",
"print \"\\n Maximum flow rate of air is \",w ,\" kg/s\"\n",
"print \"\\n Static temperature is \",T2 ,\" K\"\n",
"print \"\\n Static Pressure is \",P2 ,\" kPa\"\n",
"print \"\\n Velocity at the exit from the nozzle is \",V2 ,\" m/s\"\n",
"#The answers vary due to round off error\n",
"\n",
"# Part (b)\n",
"Mb = 0.308 # Mach number\n",
"P2P0b = 0.936 # Pressure ratio\n",
"T2T0b = 0.9812 # Temperature ratio\n",
"P2b = P2P0b*P0*1e3#Static Pressure \n",
"T2b = T2T0b*T0 # Static temperature\n",
"c2b = math.sqrt(g*R*T2b*1000) # Velocity \n",
"V2b = c2b*Mb #Velocity at the exit from the nozzle\n",
"print \"\\n\\n When divergent section act as a diffuser\"\n",
"print \"\\n Maximum flow rate of air is \",w ,\" kg/s\"\n",
"print \"\\n Static temperature is \",T2b ,\" K\"\n",
"print \"\\n Static Pressure is \",P2b ,\" kPa\"\n",
"print \"\\n Velocity at the exit from the nozzle is \",V2b ,\" m/s\"\n",
"\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Ex17.4:pg-720"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\n",
" Example 17.4\n",
"\n",
"\n",
" Mach number of the tunnel is 1.735\n"
]
}
],
"source": [
"import math\n",
"Px = 16.0 # pressure in kPa\n",
"Poy = 70.0 #pressure in kPa \n",
"Mx = 1.735 # Mach number\n",
"Pyx = 3.34 # Pressure ratio\n",
"rho_yx = 2.25 # Density ratio\n",
"Tyx = 1.483 # Temperature ratio\n",
"Poyox = 0.84 # pressure ratio\n",
"My = 0.631 # Mach number\n",
"g = 1.4 # Ratio of heat capacities\n",
"Tox = 573.0 # stagnation temperature in K \n",
"Toy = Tox # temperature equivalence\n",
"Tx = Tox/(1+((g-1)/2.0)*Mx**2) # temperature at x\n",
"Ty = Tyx*Tx # temperature at y\n",
"Pox = Poy/Poyox # total pressure \n",
"# From table\n",
"Mx = 1.735\n",
"\n",
"print \"\\n Example 17.4\\n\"\n",
"print \"\\n Mach number of the tunnel is \",Mx\n",
"\n",
"\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Ex17.5:pg-721"
]
},
{
"cell_type": "code",
"execution_count": 9,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\n",
" Example 17.5\n",
"\n",
"\n",
" Exit Mach number is 0.402\n",
"\n",
" Exit pressure is 147.9260475 kPa\n",
"\n",
" Exit Stagnation pressure is 44.7195 kPa\n",
"\n",
" Entropy increase is 0.068726024552 kJ/kg K\n"
]
}
],
"source": [
"import math\n",
"Ax = 18.75 # cross sectional area in divergent part in m**2\n",
"A_ = 12.50 # throat area in m**2\n",
"AA_ = 1.5 # Area ratio\n",
"Pxox = 0.159 # pressure ratio from table\n",
"R = 0.287 # Gas constant\n",
"Pox = 0.21e03 # pressure in kPa\n",
"Px = Pxox*Pox # pressure calculation\n",
"# from the gas table on normal shock\n",
"Mx = 1.86 \n",
"My = 0.604 \n",
"Pyx = 3.87 \n",
"Poyx = 4.95 \n",
"Poyox = 0.786\n",
"Py = Pyx*Px\n",
"Poy = Poyx*Px\n",
"My = 0.604\n",
"Ay_ = 1.183\n",
"A2 = 25 \n",
"Ay = 18.75\n",
"A2_ = (A2/Ay)*Ay_\n",
"# From isentropic table \n",
"M2 = 0.402\n",
"P2oy = 0.895\n",
"P2 = P2oy*Poy\n",
"syx = -R*math.log(Poy/Pox) # sy-sx\n",
"\n",
"print \"\\n Example 17.5\\n\"\n",
"print \"\\n Exit Mach number is \",M2\n",
"print \"\\n Exit pressure is \",P2 ,\" kPa\"\n",
"print \"\\n Exit Stagnation pressure is \",Pox-Poy ,\" kPa\"\n",
"print \"\\n Entropy increase is \",syx ,\" kJ/kg K\"\n",
"#The answers vary due to round off error\n",
"\n"
]
}
],
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