.MCAD 304020000 1 76 103 0 .CMD FORMAT rd=d ct=10 im=i et=3 zt=15 pr=3 mass length time charge temperature tr=0 vm=0 .CMD SET ORIGIN 0 .CMD SET TOL 0.001000000000000 .CMD SET PRNCOLWIDTH 8 .CMD SET PRNPRECISION 4 .CMD PRINT_SETUP 1.200000 1.200000 1.200000 1.200000 0 .CMD HEADER_FOOTER 1 1 *empty* *empty* *empty* 0 1 *empty* |P *empty* .CMD HEADER_FOOTER_FONT fontID=14 family=Arial points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD HEADER_FOOTER_FONT fontID=15 family=Arial points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFAULT_TEXT_PARPROPS 0 0 0 .CMD DEFINE_FONTSTYLE_NAME fontID=0 name=Variables .CMD DEFINE_FONTSTYLE_NAME fontID=1 name=Constants .CMD DEFINE_FONTSTYLE_NAME fontID=2 name=Text .CMD DEFINE_FONTSTYLE_NAME fontID=4 name=User^1 .CMD DEFINE_FONTSTYLE_NAME fontID=5 name=User^2 .CMD DEFINE_FONTSTYLE_NAME fontID=6 name=User^3 .CMD DEFINE_FONTSTYLE_NAME fontID=7 name=User^4 .CMD DEFINE_FONTSTYLE_NAME fontID=8 name=User^5 .CMD DEFINE_FONTSTYLE_NAME fontID=9 name=User^6 .CMD DEFINE_FONTSTYLE_NAME fontID=10 name=User^7 .CMD DEFINE_FONTSTYLE fontID=0 family=Times^New^Roman points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFINE_FONTSTYLE fontID=1 family=Times^New^Roman points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFINE_FONTSTYLE fontID=2 family=Arial points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFINE_FONTSTYLE fontID=4 family=Arial points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFINE_FONTSTYLE fontID=5 family=Courier^New points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFINE_FONTSTYLE fontID=6 family=System points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFINE_FONTSTYLE fontID=7 family=Script points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFINE_FONTSTYLE fontID=8 family=Roman points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFINE_FONTSTYLE fontID=9 family=Modern points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD DEFINE_FONTSTYLE fontID=10 family=Times^New^Roman points=10 bold=0 italic=0 underline=0 colrid=-1 .CMD UNITS U=1 .CMD DIMENSIONS_ANALYSIS 0 0 .CMD COLORTAB_ENTRY 0 0 0 .CMD COLORTAB_ENTRY 128 0 0 .CMD COLORTAB_ENTRY 0 128 0 .CMD COLORTAB_ENTRY 128 128 0 .CMD COLORTAB_ENTRY 0 0 128 .CMD COLORTAB_ENTRY 128 0 128 .CMD COLORTAB_ENTRY 0 128 128 .CMD COLORTAB_ENTRY 128 128 128 .CMD COLORTAB_ENTRY 192 192 192 .CMD COLORTAB_ENTRY 255 0 0 .CMD COLORTAB_ENTRY 0 255 0 .CMD COLORTAB_ENTRY 255 255 0 .CMD COLORTAB_ENTRY 0 0 255 .CMD COLORTAB_ENTRY 255 0 255 .CMD COLORTAB_ENTRY 0 255 255 .CMD COLORTAB_ENTRY 255 255 255 .TXT 5 14 8 0 0 0 Cg a45.125000,45.125000,39 {\rtf1\ansi \deff0{\fonttbl{\f0\fcharset0\fnil Arial;}}{\stylesheet{ \cf1\f0\fs20 Normal;}{\s1\f0\fs28\b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4\f0\fs20 \fi420 Paragraph;}{\s5 \f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48 \b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\fs28\b \pard\plain\s1\f0\fs28\b Letting Mathcad Handle Unit Conversions} .TXT 5 -13 4 0 0 0 Cg a72.000000,72.000000,528 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 For historical reasons, we are often faced with performing calculations involving quantities from both the SI system and the English engineering units. Conversion of units is a major headache and also the major source of errors in most student's work. This Mathcad module shows how to perform these unit conversions automatically with little extra effort by the student. \par \par To illustrate, we will take a few calculations from our first Hwk assignment. In particular, we will look at the solution to Prob. 4.3-8 in Geankoplis. } .TXT 16 0 10 0 0 0 Cg a72.250000,72.250000,61 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 The heat transfer coefficient {\i h}{\i\dn i} is given as 500 btu/h.ft{\up 2}.{ \up o}F} .EQN 5 0 11 0 0 0 {0:hi}NAME:500 .TXT 0 34 12 0 0 0 Cg a38.250000,38.250000,70 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 If we define hi to be 500, Mathcad take the number to be diminsionless} .TXT 6 -34 19 0 0 0 Cg a71.250000,71.250000,676 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 To get Mathcad to make the unit conversions, we must assign the units to all constants instead of leaving them dimensionless. This can be done by multiplying (or dividing) the constant "500" by built-in constants representing the units. This is done in the example below: after typing "500", I typed the "multiply" symbol (*) and then typed "BTU". { \ul You must use the }{\i\ul exact}{\ul name Mathcad uses for each unit (including upper or lower case)}. If you don't remember the name of the unit, click on the "measuring cup" in the toolbar (if the 'toolbar' is not visible, go to the View menu and click on 'toolbar'). A dialog box will appear which allows you to select the proper unit.} .TXT 15 28 80 0 0 0 Cg a43.875000,43.875000,231 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 After entering "BTU", I typed "/hr*ft^2 *R" (the blank denotes a space made by hitting the space bar). Again, if I didn't know Mathcad's name for a unit, I can insert it at the current cursor location using the measuring cup tool.} .EQN 3 -27 32 0 0 0 {0:hi}NAME:500*({0:BTU}NAME)/({0:hr}NAME*({0:ft}NAME)^(2)*{0:R}NAME) .TXT 7 -1 27 0 0 0 Cg a70.500000,70.500000,135 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 Once you have defined a variable like "hi", you can either use it in any calculations or display its value in any desired set of units.} .TXT 7 28 76 0 0 0 Cg a44.750000,44.750000,278 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 If you just type "=" after the constant, Mathcad displays the value in its default set of units (usually MKS unless you have declared a different default). Notice that the value displayed at left (as well as the units) are different from what we entered in the statement above.} .EQN 1 -28 28 0 0 0 {0:hi}NAME={0}?_n_u_l_l_ .TXT 11 0 34 0 0 0 Cg a72.250000,72.250000,311 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 If you click on the equation above, you will notice a placeholder appears at the end of the list of units. This placeholder is denoted by a solid square (about 1mm x 1mm in size). Moving the cursor to select this placeholder, you can enter any desired units in which the value of constant are to be displayed.} .TXT 9 27 59 0 0 0 Cg a44.375000,44.375000,259 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 For example, if we enter "kW/m^2 *K" in this placeholder, we obtain the result at left. Notice that the value of hi has changed to reflect the different units used. Mathcad has automatically applied the conversion 1 kW = 1000 joules/sec = 1000 kg*m/sec^3. } .EQN 3 -27 52 0 0 0 {0:hi}NAME={0}?({0:kW}NAME)/(({0:m}NAME)^(2)*{0:K}NAME) .TXT 9 27 60 0 0 0 Cg a43.625000,43.625000,237 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 If we incorrectly enter the units as "BTU/ft^2 *R" (we have omitted the hr), Mathcad uses them, but appends the default unit of time "s^-1" to indicate that additional units are required. Of course, we do not recover our original value.} .EQN 4 -27 53 0 0 0 {0:hi}NAME={0}?({0:BTU}NAME)/(({0:ft}NAME)^(2){53}{0:R}NAME) .TXT 8 27 61 0 0 0 Cg a43.250000,43.250000,128 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 If instead, we enter "BTU/hr*ft^2 *R" (including the "hr") in the units placeholder, we do recover the original value and units.} .EQN 1 -27 57 0 0 0 {0:hi}NAME={0}?({0:BTU}NAME)/({0:hr}NAME*({0:ft}NAME)^(2)*{0:R}NAME) .TXT 6 0 65 0 0 0 Cg a72.250000,72.250000,108 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 Now we will enter the rest of the variables appearing in this problem in the most convenient units (for us).} .EQN 8 0 66 0 0 0 {0:ho}NAME:1500*({0:BTU}NAME)/({0:hr}NAME*({0:ft}NAME)^(2)*{0:R}NAME) .EQN 0 20 68 0 0 0 {0:k}NAME:45.1*({0:W}NAME)/({0:m}NAME*{0:K}NAME) .EQN 0 15 69 0 0 0 {0:Di}NAME:2.067*{0:in}NAME .EQN 0 13 70 0 0 0 {0:Do}NAME:2.375*{0:in}NAME .EQN 7 -48 75 0 0 0 {0:xW}NAME:({0:Do}NAME-{0:Di}NAME)/(2) .EQN 0 20 82 0 0 0 {0:xW}NAME={0}?{0:in}NAME .TXT 0 15 84 0 0 0 Cg a37.250000,37.250000,93 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 Here we calculate the wall thickness. I specified "in" as the unit to display the answer in.} .TXT 7 0 86 0 0 0 Cg a37.250000,37.250000,99 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 Here we calculate the log-mean diameter. Again I specified "in" as the unit to display the result.} .EQN 1 -34 87 0 0 0 {0:Dlm}NAME:({0:Do}NAME-{0:Di}NAME)/({0:ln}NAME(({0:Do}NAME)/({0:Di}NAME))) .EQN 0 19 83 0 0 0 {0:Dlm}NAME={0}?{0:in}NAME .TXT 7 11 103 0 0 0 Cg a40.000000,40.000000,278 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 Here we are calculating the overall coefficient using the formula at the top of page 9 of the class notes. Notice that we have mixed different sets of units when specifying values for the variables appearing in this equation. The units are correctly converted automatically. } .EQN 2 -30 88 0 0 0 {0:Uo}NAME:(1)/((1)/({0:ho}NAME)+({0:xW}NAME)/({0:k}NAME)*({0:Do}NAME)/({0:Dlm}NAME)+(1)/({0:hi}NAME)*({0:Do}NAME)/({0:Di}NAME)) .TXT 14 34 93 0 0 0 Cg a37.250000,37.250000,63 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 This is the display of the result using Mathcad's default units} .EQN 1 -34 91 0 0 0 {0:Uo}NAME={0}?_n_u_l_l_ .EQN 9 0 94 0 0 0 {0:Uo}NAME={0}?({0:BTU}NAME)/({0:hr}NAME*({0:ft}NAME)^(2)*{0:R}NAME) .TXT 0 34 102 0 0 0 Cg a37.250000,37.250000,139 {\rtf1\ansi \deff0{\colortbl;\red0\green0\blue0;}{\fonttbl{\f0 \fcharset0\fnil Arial;}}{\stylesheet{\cf1\f0\fs20 Normal;}{\s1\f0\fs28 \b Heading 1;}{\s2\f0\fs24\b\i Heading 2;}{\s3\f0\fs24 Heading 3;}{\s4 \f0\fs20 \fi420 Paragraph;}{\s5\f0\fs20 \li285\fi-285 List;}{\s6\f0\fs20 \li2160 Indent;}{\s7\f1\fs48\b \qc Title;}{\s8\f1\fs36 \qc \sbasedon0 Subtitle;}}\plain\cf1\fs20 \pard\plain\s0\cf1\f0\fs20 What remains is the display of the answer in two different sets of units. The last value should match with the answer in the solution key.} .EQN 7 -34 95 0 0 0 {0:Uo}NAME={0}?({0:W}NAME)/(({0:m}NAME)^(2)*{0:K}NAME)