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{
"metadata": {
"name": "",
"signature": "sha256:da3557673ab31ece618ad10f5b0d3ef78112ff36bd0b260e508d99211060a1c9"
},
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"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 4:WORK AND HEAT"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex4.1:PG-96"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#example 1\n",
"#work done during different processes\n",
"import math\n",
"\n",
"P1=200 #initial pressure inside cylinder in kPa\n",
"V2=0.1 #in m^3\n",
"V1=0.04 #initial volume of gas in m^3\n",
"\n",
"W1=P1*(V2-V1) #work done in isobaric process in kJ\n",
"print\"\\n hence,the work done during the isobaric process is\",round(W1,2),\"kJ. \\n\"\n",
"\n",
"W2=P1*V1*math.log(V2/V1) #work done in isothermal process in kJ\n",
"print\"\\n hence,the work done in isothermal process is\",round(W2,2),\"kJ. \\n\"\n",
"\n",
"P2=P1*(V1/V2)**(1.3) #final pressure according to the given process\n",
"W3=(P2*V2-P1*V1)/(1-1.3)\n",
"print\"\\n hence,the work done during the described process is\",round(W3,2),\"kJ. \\n\"\n",
"\n",
"W4=0 #work done in isochoric process\n",
"print\"\\n hence,the work done in the isochoric process is\",round(W4,3),\"kJ. \\n\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n",
" hence,the work done during the isobaric process is 12.0 kJ. \n",
"\n",
"\n",
" hence,the work done in isothermal process is 7.33 kJ. \n",
"\n",
"\n",
" hence,the work done during the described process is 6.41 kJ. \n",
"\n",
"\n",
" hence,the work done in the isochoric process is 0.0 kJ. \n",
"\n"
]
}
],
"prompt_number": 16
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex4.3:PG-99"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#example 3\n",
"\n",
"#work produced\n",
"\n",
"Psat=190.2 #in kPa\n",
"P1=Psat #saturation pressure in state 1\n",
"vf=0.001504 #in m^3/kg\n",
"vfg=0.62184 #in m^3/kg\n",
"x1=0.25 #quality\n",
"v1=vf+x1*vfg #specific volume at state 1 in m^3/kg\n",
"v2=1.41*v1 #specific volume at state 2 in m^3/kg\n",
"P2=600 #pressure in state 2 in kPa from Table B.2.2\n",
"m=0.5 #mass of ammonia in kg\n",
"W=m*(P1+P2)*(v2-v1)/2 #woork produced by ammonia in kJ\n",
"print \"The final pressure is\",round(P2),\"kPa\\n\"\n",
"print \"hence,work produced by ammonia is\",round(W,2),\"kJ\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The final pressure is 600.0 kPa\n",
"\n",
"hence,work produced by ammonia is 12.71 kJ\n"
]
}
],
"prompt_number": 10
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex4.4:PG-100"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#example 4\n",
"\n",
"#calculating work done\n",
"\n",
"v1=0.35411 #specific volume at state 1 in m^3/kg\n",
"v2=v1/2 \n",
"m=0.1 #mass of water in kg\n",
"P1=1000 #pressure inside cylinder in kPa\n",
"W=m*P1*(v2-v1) #in kJ\n",
"print \"the work in the overall process is\",round(W,1),\"kJ\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"the work in the overall process is -17.7 kJ\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex4.7:PG-108"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#example 7\n",
"#heat transfer\n",
"k=1.4 #conductivity of glass pane in W/m-K\n",
"A=0.5 #total surface area of glass pane\n",
"dx=0.005 #thickness of glasspane in m\n",
"dT1=20-12.1 #temperature difference between room air and outer glass surface temperature in celsius\n",
"Q=-k*A*dT1/dx #conduction through glass slab in W\n",
"h=100 #convective heat transfer coefficient in W/m^2-K \n",
"dT=12.1-(-10) #temperature difference between warm room and colder ambient in celsius\n",
"Q2=h*A*dT #heat transfer in convective layer in W\n",
"#result\n",
"print \"the rate of heat transfer in the glass and convective layer is\",round(Q2),\"kW.\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"the rate of heat transfer in the glass and convective layer is 1105.0 kW.\n"
]
}
],
"prompt_number": 1
}
],
"metadata": {}
}
]
}
|
