{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 17 - Fluid Flow : Nozzles and Orifices"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1a - Pg 299"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#calculate the exit area\n",
"#initialization of varaibles\n",
"import math\n",
"w=1 #lb/sec\n",
"v2=36.4\n",
"h1=1279.1 #B/lb\n",
"h2=1091.7 #B/lb\n",
"V1=100 #fps\n",
"#calculations\n",
"a2=w*v2/(math.sqrt(2*32.2*778*(h1-h2) + V1*V1)) #sq ft\n",
"a2=1.705 #sq in\n",
"#results\n",
"print '%s %.3f %s' %(\"Exit area =\",a2,\"sq. in\")\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Exit area = 1.705 sq. in\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1b - Pg 300"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Calculate the throat area\n",
"#initialization of varaibles\n",
"import math\n",
"w=1 #lb/sec\n",
"k=1.3\n",
"P=100 #psia\n",
"#calculations\n",
"Pratio=math.pow((2/(k+1)),(k/(k-1)))\n",
"Pt=Pratio*P\n",
"print '%s' %(\"From table 3,\")\n",
"ht=1221.5 #B/lb\n",
"vt=8.841 #cu ft/lb\n",
"at=w*vt/1700.\n",
"#results\n",
"print '%s %.4f %s' %(\"Throat area =\",at,\"sq ft\")\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"From table 3,\n",
"Throat area = 0.0052 sq ft\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2 - Pg 309"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Calculate the Throat and exit areas for both frictionless and frictioned nozzles\n",
"#initialization of varaibles\n",
"import math\n",
"k=1.3\n",
"P=250 #psia\n",
"h0=1263.4 #B/lb\n",
"w=10000. #lb\n",
"cv=0.949\n",
"vts=3.415 #cu ft/lb\n",
"#calculations\n",
"Pratio=math.pow((2/(k+1)),(k/(k-1)))\n",
"Pt=Pratio*P\n",
"hts=1208.2 #B/lb\n",
"h2s=891 #B/lb\n",
"Vts=math.sqrt(2*32.2*778*(h0-hts))\n",
"w=w/3600. #lb/sec\n",
"at=w*vts/(Vts)\n",
"V2=cv*math.sqrt(2*32.2*778*(h0-h2s))\n",
"etan=cv*cv\n",
"h2=928. #B/lb\n",
"print '%s' %(\"From table 3,\")\n",
"v2=276. #cu ft/lb\n",
"a2=w*v2/V2\n",
"a2s=0.17 #ft^2\n",
"Cw=0.98\n",
"at2=at/Cw\n",
"#results\n",
"print '%s %.5f %s' %(\"\\n Throat area =\",at,\"ft^2\")\n",
"print '%s %.3f %s' %(\"\\n Exit area =\",a2,\"ft^2\")\n",
"print '%s %.3f %s' %(\"\\n For frictionless nozzle =\",a2s,\"ft^2\")\n",
"print '%s %.5f %s' %(\"\\n Changed throat area =\",at2,\"ft^2 and exit area is unchanged\")\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"From table 3,\n",
"\n",
" Throat area = 0.00570 ft^2\n",
"\n",
" Exit area = 0.187 ft^2\n",
"\n",
" For frictionless nozzle = 0.170 ft^2\n",
"\n",
" Changed throat area = 0.00582 ft^2 and exit area is unchanged\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3a - Pg 310"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#calculate the Exit velocity, throat and exit areas\n",
"#initialization of varaibles\n",
"import math\n",
"w=1 #lb/sec\n",
"Pratio=0.53\n",
"k=1.4\n",
"T0=800. #R\n",
"cp=0.24\n",
"P0=150. #psia\n",
"P2=15. #psia\n",
"#calculations\n",
"Pt=Pratio*P0\n",
"Tratio=math.pow((Pratio),((k-1)/k))\n",
"Tts=T0*Tratio\n",
"Vts=math.sqrt(2*32.2*778*cp*(T0-Tts))\n",
"vts=53.34*Tts/(Pt*144.)\n",
"at=w*vts/(Vts)\n",
"T2s=T0*math.pow((Pt/P0),((k-1)/k))\n",
"T2=460. #R\n",
"V2=math.sqrt(2*32.2*cp*778*(T0-T2))\n",
"v2=53.34*T2/(144.*P2)\n",
"a2=w*v2/V2\n",
"#results\n",
"print '%s %d %s' %(\"Exit velocity =\",Vts,\"fps\")\n",
"print '%s %.5f %s' %(\"\\n Throat area =\",at,\"ft^2\")\n",
"print '%s %.5f %s' %(\"\\n Exit area =\",a2,\"ft^2\")\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Exit velocity = 1263 fps\n",
"\n",
" Throat area = 0.00246 ft^2\n",
"\n",
" Exit area = 0.00562 ft^2\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 3b - Pg 310"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#calculate the Exit velocity, throat and exit areas\n",
"#initialization of varaibles\n",
"import math\n",
"h0=191.81 #B/lb\n",
"Pr0=5.526\n",
"w=1 #lb/sec\n",
"Pratio=0.53\n",
"k=1.4\n",
"T0=800. #R\n",
"cp=0.24\n",
"P0=150. #psia\n",
"P2=15. #psia\n",
"Pt=79.5 #psia\n",
"#calculations\n",
"Prt=Pratio*Pr0\n",
"print '%s' %(\"From keenan and kaye steam tables,\")\n",
"Pr=2.929\n",
"Tts=668 #R\n",
"hts=159.9 #B/lb\n",
"Vts=math.sqrt(2*32.2*778*(h0-hts))\n",
"vts=53.34*Tts/(Pt*144.)\n",
"at=w*vts/(Vts)\n",
"Pr2=P2*Pr0/P0\n",
"T2s=415 #R\n",
"h2s=99.13 #B/lb\n",
"h2=110.25 #B/lb\n",
"T2=462 #R\n",
"V2=math.sqrt(2*32.2*778*(h0-h2))\n",
"v2=53.34*T2/(144.*P2)\n",
"a2=w*v2/V2\n",
"#results\n",
"print '%s %d %s' %(\"Exit velocity =\",Vts,\"fps\")\n",
"print '%s %.5f %s' %(\"\\n Throat area =\",at,\"ft^2\")\n",
"print '%s %.5f %s' %(\"\\n Exit area =\",a2,\"ft^2\")\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"From keenan and kaye steam tables,\n",
"Exit velocity = 1264 fps\n",
"\n",
" Throat area = 0.00246 ft^2\n",
"\n",
" Exit area = 0.00564 ft^2\n"
]
}
],
"prompt_number": 5
}
],
"metadata": {}
}
]
}