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{
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 18 - Turbines"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1 - Pg 336"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#calculate work done, axial thrust and nozzle bucket efficiency\n",
"#initialization of varaibles\n",
"import math\n",
"drop=50. #B/lb\n",
"cv=0.95\n",
"Vb=700. #fps\n",
"alpha=20.*math.pi/180. #radians\n",
"beta=30.*math.pi/180. #radians\n",
"Cb=0.95\n",
"#calculations\n",
"V1=cv*math.sqrt(2*32.2*778*drop)\n",
"y1=V1*math.cos(alpha)\n",
"z1=V1*math.sin(alpha)\n",
"y1R=y1-Vb\n",
"V1R=math.sqrt(y1R*y1R + z1*z1)\n",
"V2R=Cb*V1R\n",
"y2R=-V2R*math.cos(beta)\n",
"z2=V2R*math.sin(beta)\n",
"Wx=(y1R-y2R)*Vb/32.2\n",
"Fa=(z1-z2)/32.2\n",
"Vc=1582.77\n",
"etanb=Wx/(Vc*Vc /(2*32.2))\n",
"#results\n",
"print '%s %d %s' %(\"Work per pound of fluid =\",Wx,\"ft lbf/lbm\")\n",
"print '%s %.1f %s' %(\"\\n Axial thrust =\",Fa,\"lbf/lbm/sec\")\n",
"print '%s %.2f' %(\"\\n Nozzle bucket efficiency = \",etanb)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Work per pound of fluid = 31221 ft lbf/lbm\n",
"\n",
" Axial thrust = 3.0 lbf/lbm/sec\n",
"\n",
" Nozzle bucket efficiency = 0.80\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2 - Pg 349"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Calculate the internal efficiency and the reheat factor\n",
"#initialization of varaibles\n",
"ha=1187.2 #B/lb\n",
"sa=1.6026 #B/lb R\n",
"h3s=895 #B/lb\n",
"h1s=1090 #B/lb\n",
"p1=28 #psia\n",
"h2s=993 #B/lb\n",
"p2=6.2 #psia\n",
"n=0.65\n",
"#calculations\n",
"print '%s' %(\"From Table 3,\")\n",
"h1=ha-n*(ha-h1s)\n",
"s1=1.65 #B/lb R\n",
"h2dash=1024 #B/lb\n",
"h2=h1-n*(h1-h2dash)\n",
"s2=1.706 #B/lb R\n",
"h3dash=953. #B/lb\n",
"h3=h2-n*(h2-h3dash)\n",
"etaT=(ha-h3)/(ha-h3s)\n",
"reheat=etaT/n\n",
"#results\n",
"print '%s %.3f' %(\"Internal efficiency = \",etaT)\n",
"print '%s %.2f' %(\"\\n Reheat factor = \",reheat)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"From Table 3,\n",
"Internal efficiency = 0.675\n",
"\n",
" Reheat factor = 1.04\n"
]
}
],
"prompt_number": 2
}
],
"metadata": {}
}
]
}
|