S4-1 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation SECTION 4 CONVECTION. - презентация

1 S4-1 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation SECTION 4 CONVECTION

2 S4-2 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n Based on Exercise 1c(page 97) in the MSC/NASTRAN Thermal Analysis Users Guide n One end of the aluminum rod is held at K n The rod loses heat to a fluid fixed at K n Perform a SS analysis and review the.DAT and.F06 files

3 S4-3 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n In the MSC/NASTRAN Thermal Analysis Users Guide the diameter and length of the aluminum rod were specified as 0.1m and 0.5m, respectively

4 S4-4 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n Create the finite element mesh u Create a curve 0.5 units long u Create 5 mesh seeds on the curve u Mesh the curve with the IsoMesh l The value of the Global Edge Length does not affect the meshing

5 S4-5 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n Create the material properties u Constant thermal conductivity

6 S4-6 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n Create the 1D finite element properties u 1D rod u Constant cross- section area u The application region is the curve, Curve 1

7 S4-7 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n Create a fixed temperature BC at one end of the rod u Specify 1300 degrees K u Apply at Point 1

8 S4-8 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n Create a temperature varying convection coefficient, h = h(T) u Specify the data using tabular input u Set the function to only vary with temperature

9 S4-9 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n Create temperature varying convection u Element Uniform instead of Nodal u Use To Ambient u 1D u Scale factor for the convection coefficient of 1.0 u Ambient temp of u Exponent of 0.25 u Use h = h(T) field u Apply to Curve 1

10 S4-10 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n Run SS simulation u Default initial temperature of 900 degrees K u No radiation for this problem n Read the results

11 S4-11 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) n Create a plot of temperature versus the path defined by Nodes 1:6

12 S4-12 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP)

13 S4-13 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) $ NASTRAN input file created by the MSC MSC/NASTRAN input file $ translator ( MSC/PATRAN Version 7.5 ) on July 06, 1998 at $ 11:12:53. ASSIGN OUTPUT2 = 'project3.op2', UNIT = 12 $ Direct Text Input for File Management Section $ Steady State Analysis, Database SOL 153 TIME 600 $ Direct Text Input for Executive Control CEND ANALYSIS = HEAT TITLE = MSC/NASTRAN job created on 06-Jul-98 at 11:12:05 ECHO = SORT MAXLINES = TEMPERATURE(INITIAL) = 1 $ Direct Text Input for Global Case Control Data SUBCASE 1 $ Subcase name : Default SUBTITLE=Default NLPARM = 1 SPC = 1 THERMAL(SORT1,PRINT)=ALL FLUX(SORT1,PRINT)=ALL Extracted from MSC.Nastran model.DAT file

14 S4-14 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) BEGIN BULK NLPARM 1 0 AUTO 5 25 PW NO + A + A $ Direct Text Input for Bulk Data $ Elements and Element Properties for region : rod PROD CROD CROD CROD CROD CROD $ Referenced Material Records $ Material Record : alum $ Description of Material : Date: 06-Jul-98 Time: 10:53:38 MAT $ Nodes of the Entire Model GRID GRID GRID GRID GRID GRID Extracted from MSC.Nastran model.DAT file

15 S4-15 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) $ Fixed Temperatures of Load Set : left SPC $ Fixed Temperatures of Load Set : conv SPC $ Convection to Ambient of Load Set : conv PCONV CONV CONV CONV CONV CONV $ Initial Temperatures from Temperature Load Sets TEMP $ Default Initial Temperature TEMPD $ CHBDYP Surface Elements and Element Properties CHBDYP 1 1 LINE B + B CHBDYP 2 1 LINE C + C CHBDYP 3 1 LINE D + D CHBDYP 4 1 LINE E + E CHBDYP 5 1 LINE F + F PHBDY $ Free Convection Heat Transfer Coefficients MAT MATT $ Material Tables ( No Conversions Needed ) $ Temperature Dependent Material Table : h_temp TABLEM1 1 + G + G ENDT $ Scalar Points SPOINT 7 $ Referenced Coordinate Frames ENDDATA Extracted from MSC.Nastran model.DAT file

16 S4-16 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) $ Free Convection Heat Transfer Coefficients MAT MATT $ Material Tables ( No Conversions Needed ) $ Temperature Dependent Material Table : h_temp TABLEM1 1 + G + G ENDT $ Scalar Points SPOINT 7 $ Referenced Coordinate Frames ENDDATA Extracted from MSC.Nastran model.DAT file

17 S4-17 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) 0 0 N O N - L I N E A R I T E R A T I O N M O D U L E O U T P U T STIFFNESS UPDATE TIME 0.09 SECONDS SUBCASE 1 ITERATION TIME 0.01 SECONDS LOAD FACTOR CONVERGENCE FACTORS LINE SEARCH DATA ITERATION EUI EPI EWI LAMBDA DLMAG FACTOR E-FIRST E-FINAL NQNV NLS ENIC NDV MDV E E E E E E E E E E E E E E E E E E E E E E E E *** USER INFORMATION MESSAGE 6186, *** SOLUTION HAS CONVERGED *** SUBID 1 LOOPID 1 LOAD STEP LOAD FACTOR Extract from MSC.Nastran ASCII Results File

18 S4-18 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 3 FREE CONVECTION, H=H(TEMP) 0 SUBCASE 1 LOAD STEP = E+00 T E M P E R A T U R E V E C T O R POINT ID. TYPE ID VALUE ID+1 VALUE ID+2 VALUE ID+3 VALUE ID+4 VALUE ID+5 VALUE 1 S E E E E E E+03 7 S E+02 1 MSC/NASTRAN JOB CREATED ON 06-JUL-98 AT 11:12:05 JULY 6, 1998 MSC/NASTRAN 12/11/96 PAGE 11 DEFAULT 0 SUBCASE 1 LOAD STEP = E+00 H E A T F L O W I N T O H B D Y E L E M E N T S (CHBDY) ELEMENT-ID APPLIED-LOAD FREE-CONVECTION FORCED-CONVECTION RADIATION TOTAL E E E E E E E E E E E E E E E E E E E E E E E E E+02 Extract from MSC.Nastran ASCII Results File

19 S4-19 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation n Perform Workshop 3 Free Convection From Printed Circuit Board in the exercise workbook. EXERCISES

20 S4-20 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS n Based on Project 4 in the MSC.Nastran Thermal Analysis Users Guide n Water flowing at 0.1kg/sec enters a 0.05 m diameter tube n The inlet is fixed at C n Heat is convected away from the flow to a wall temperature of 0.0 C n The convection coefficient is constant at 200 watts/(m**2*C) n Run a SS analysis to determine the outlet temperature n Illustrates use of CHBDYP (FTUBE)

21 S4-21 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS n Create a curve 5 m long in the X-direction n Mesh seed for 10 elements on Curve 1 n IsoMesh Curve 1 u The mesh seeds control how many 1D bar elements are created on the curve

22 S4-22 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS n Specify the properties for the fluid n Necessary to specify u K u Cp u Rho u Mu

23 S4-23 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS n Define 10 flow tubes on Curve 1 u Type: Flow Tube u Material property set, fluid u Hydraulic diameter = 4*A/P = 4*pi*R**2/(2*pi*R) = 2*R = D

24 S4-24 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS n Specify inlet temperature of fluid in tube u C u Point 1 at one end of the tube

25 S4-25 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS n Define forced convection from flow in tube to ambient temperature u Option: Flow Tube To Ambient u Target Element Type: 1D l Only 1D because flow tube u Mdot = 0.1 kg/sec u Tamb = 0 C u h = 200 Watts/(m**2*C) u All flow tubes on Curve 1

26 S4-26 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS n Note that the inlet temperature is 100 degrees C, and the fluid temperature decreases as the fluid travels down the duct

27 S4-27 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS n The fluid temperature at X = 0(inlet) is 100 degrees C, and the fluid temperature has decreased to 69.6 C at X = 5(tube exit).

28 S4-28 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS GRID GRID GRID $ CHBDYP 1 1 FTUBE 1 2 CHBDYP 2 1 FTUBE CHBDYP 10 1 FTUBE PHBDY $ Scalar Points SPOINT 12 THRU 13 $Tube Flow Convection to Ambient of Load Set : forced CONVM CONVM CONVM PCONVM MAT Extracted from MSC.Nastran model.DAT file

29 S4-29 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS $ Loads for Load Case : Default $ Fixed Temperatures of Load Set : Fluid_inlet SPC $ Fixed Temperatures of Load Set : forced $ Note that the SPOINT 13 represent the Mass flow rate $ The SPOINT 12 represents the ambient temperature at $ Zero degree SPC SPC Extracted from MSC.Nastran model.DAT file

30 S4-30 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4 1D FLOW NETWORKS 0 SUBCASE 1 LOAD STEP = E+00 T E M P E R A T U R E V E C T O R POINT ID. TYPE ID VALUE ID+1 VALUE ID+2 VALUE ID+3 VALUE ID+4 VALUE ID+5 VALUE 1 S E E E E E E+01 7 S E E E E E S E-01 0 SUBCASE 1 LOAD STEP = E+00 H E A T F L O W I N T O H B D Y E L E M E N T S (CHBDY) ELEMENT-ID APPLIED-LOAD FREE-CONVECTION FORCED-CONVECTION RADIATION TOTAL E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E+00 Extract from MSC.Nastran ASCII Results File

31 S4-31 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 4, PART 2 1D FLOW NETWORKS 0 SUBCASE 1 LOAD STEP = E+00 T E M P E R A T U R E V E C T O R POINT ID. TYPE ID VALUE ID+1 VALUE ID+2 VALUE ID+3 VALUE ID+4 VALUE ID+5 VALUE 1 S E E E E E E+01 7 S E E E E E S E-01 1 MSC/NASTRAN JOB CREATED ON 06-JUL-98 AT 15:33:40 JULY 6, 1998 MSC/NASTRAN 12/11/96 PAGE 11 DEFAULT 0 SUBCASE 1 LOAD STEP = E+00 H E A T F L O W I N T O H B D Y E L E M E N T S (CHBDY) ELEMENT-ID APPLIED-LOAD FREE-CONVECTION FORCED-CONVECTION RADIATION TOTAL E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E+03 Extract from MSC.Nastran ASCII Results File

32 S4-32 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation n Perform Workshop 4 Forced Air Convection From Printed Circuit Board in the exercise workbook. EXERCISES

33 S4-33 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION Coupled Advection for a Heat Exchanger

34 S4-34 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Aluminum heat sink with a dimension of 1 inch height(Y-direction), 0.5 inch wide(Z-direction), and 3 inches in length(X-direction). n The channel section is 0.8 inch by 0.4 inch n The fluid is air, and the inlet temperature is 20 degrees C

35 S4-35 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n The inlet mass flow rate is lbm/sec. n The heat flux is imposed on one face(1 inch by 3 inch) with a value of 20 watts/inch**2 n The convection coefficient is assumed to be constant at 0.3 watt/inch**2*C

36 S4-36 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Objective: Determine the exit fluid temperature, and the maximum heat sink temperature. n First model is with mesh element size of 0.5 inch.

37 S4-37 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Connect fluid element(1D bar from Node 43 to Node 44) to conduction element (2D CQUAD4 using Node 1,2,23, 22). n Convect off surface element that has Node 1,2,23,22 using convection coefficient. n How can this be accomplished this using MSC.Nastran bulk data record ?

38 S4-38 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Flow resistor network u H=coefficient on the PCONVM bulk data=1.0e-20 u 1/HA = very large resistance,thus the convection comes from 1/ha. u h=user supplied convection coefficient u Tie the ambient point of the fluid nodes directly to the node on the convection surface. u MSC.Patran will locate the closest nodal points on the surface to the fluid points Tref=0 Mass flow 1/HA 1/ha Upstream fluid node

39 S4-39 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Create first side of channel n Create other side of channel

40 S4-40 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Create bottom and top of channel

41 S4-41 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n After generating four surfaces (Surface 1:4), create a curve at the center of the channel (Curve 1) where the fluid elements will be created. n CHBDYP, FTUBE element Side Bottom

42 S4-42 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Create the 2D elements that will be used for in-plane conduction and out-of-plane convection n IsoMesh the four surfaces with a coarse mesh u Quad4 topology u Surface List: Surface 1:4 u GEL = 0.5 n Connect the adjacent Quad4 elements

43 S4-43 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Create the fluid elements at the center of the channel u CHBDY(FTUBE) n IsoMesh the curve at the center of the channel u Bar2 topology u Curve List: Curve 1 u GEL = 0.5

44 S4-44 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Create the material property set for the heat sink(aluminum duct) u K = 4.0

45 S4-45 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Create the material property set for the air flowing in the channel u K u Cp u Rho u Mu

46 S4-46 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Create 2D element properties for sides of channel u Aluminum u Thickness = 0.05 u Surface 1, 2 n Create 2D element properties for bottom and top of channel u Aluminum u Thickness = 0.10 u Surface 3, 4

47 S4-47 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION

48 S4-48 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Create fixed temperature of 20 C at inlet to channel u Apply at Point 9 on one end of Curve 1

49 S4-49 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Create coupled advection between 2D shell elements and 1D flow tube elements u Convection Coefficient u Mass flow rate

50 S4-50 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n There are two regions that have to be specified u Application Region(Target Element Type: 2D) l 2D conduction/convection elements u Companion Region(Region 2: 1D) l 1D flow tube elements

51 S4-51 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n Apply a constant heat flux to one of the side surfaces u Flux = 20 Watts/in**2 u Apply to Surface 1

52 S4-52 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n The picture to the left shows the markers for coupled advection as green arrows, and for the flux as yellow arrows.

53 S4-53 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n MSC.Nastran thermal results n Temperature fringe n The temperature contour is not smooth because there were not many conduction elements and not many corresponding flow tube elements.

54 S4-54 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5 COUPLED ADVECTION n The fluid temperature rises from 20 degrees(at the inlet) to 34 degrees(at the outlet) because of the heat load.

55 S4-55 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation Coupled Advection NASTRAN test deck:project5. bdf n SOL 153 n TIME 600 n $ Direct Text Input for Executive Control n CEND n ANALYSIS = HEAT n TITLE = MSC/NASTRAN job created on 06-Jul-98 at 18:21:56 n ECHO = SORT n MAXLINES = n TEMPERATURE(INITIAL) = 1 n $ Direct Text Input for Global Case Control Data n SUBCASE 1 n $ Subcase name : Default n SUBTITLE=Default n NLPARM = 1 n SPC = 1 n LOAD = 2 n THERMAL(SORT1,PRINT)=ALL n FLUX(SORT1,PRINT)=ALL n SPCF=ALL n BEGIN BULK n PARAM POST 0 n PARAM AUTOSPC YES n NLPARM 1 0 AUTO 5 25 PW NO + A n + A n $ Direct Text Input for Bulk Data n $ Elements and Element Properties for region : heatsink n PSHELL n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n $ Elements and Element Properties for region : side n PSHELL n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n CQUAD n MAT n $ Material Record : air n $ Description of Material : Date: 06-Jul-98 Time: 17:57:13 n MAT n $ Nodes of the Entire Model n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID

56 S4-56 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation NASTRAN test deck:project5. bdf -Cont n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n GRID n $ Loads for Load Case : Default n $ Fixed Temperatures of Load Set : inlet n SPC n $ Fixed Temperatures of Load Set : advection n SPC n SPC n $ Normal Heat Flux of Load Set : flux n QBDY n QBDY n QBDY n QBDY n QBDY n QBDY n QBDY n QBDY n QBDY n QBDY n QBDY n QBDY n $ Coupled Advection of Load Set : advection n PCONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV n CONV

57 S4-57 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation NASTRAN test deck:project5. bdf n $ Coupled Advection of Load Set : advection n PCONVM* * B n * B n CONVM n CONVM n CONVM n CONVM n CONVM n CONVM n $ Initial Temperatures from Temperature Load Sets n TEMP n $ Default Initial Temperature n TEMPD n $ CHBDYG Surface Elements n CHBDYG 1 AREA4 + C n + C n CHBDYG 2 AREA4 + D n + D n CHBDYG 3 AREA4 + E n + E n CHBDYG 4 AREA4 + F n + F n CHBDYG 5 AREA4 + G n + G n CHBDYG 6 AREA4 + H n + H n CHBDYG 7 AREA4 + I n + I n CHBDYG 8 AREA4 + J n + J n CHBDYG 9 AREA4 + K n + K n CHBDYG 10 AREA4 + L n + L n CHBDYG 11 AREA4 + M n + M n CHBDYG 12 AREA4 + N n + N n CHBDYG 13 AREA4 + O n + O n CHBDYG 14 AREA4 + P n + P n CHBDYG 15 AREA4 + Q n + Q n CHBDYG 16 AREA4 + R n + R n CHBDYG 17 AREA4 + S n + S n CHBDYG 18 AREA4 + T n + T n CHBDYG 19 AREA4 + U n + U n CHBDYG 20 AREA4 + V n + V n CHBDYG 21 AREA4 + W n + W n CHBDYG 22 AREA4 + X n + X n CHBDYG 23 AREA4 + Y n + Y n CHBDYG 24 AREA4 + Z n + Z n CHBDYG 25 AREA4 + AA n + AA n CHBDYG 26 AREA4 + AB n + AB n CHBDYG 27 AREA4 + AC n + AC n CHBDYG 28 AREA4 + AD n + AD n CHBDYG 29 AREA4 + AE n + AE n CHBDYG 30 AREA4 + AF n + AF n CHBDYG 31 AREA4 + AG n + AG n CHBDYG 32 AREA4 + AH n + AH n CHBDYG 33 AREA4 + AI n + AI n CHBDYG 34 AREA4 + AJ n + AJ n CHBDYG 35 AREA4 + AK n + AK n CHBDYG 36 AREA4 + AL n + AL n $ CHBDYP Surface Elements and Element Properties n CHBDYP 37 1 FTUBE AM n + AM n CHBDYP 38 1 FTUBE AN n + AN n CHBDYP 39 1 FTUBE AO n + AO n CHBDYP 40 1 FTUBE AP n + AP n CHBDYP 41 1 FTUBE AQ n + AQ n CHBDYP 42 1 FTUBE AR n + AR n PHBDY n $ Free Convection Heat Transfer Coefficients n MAT n $ Scalar Points n SPOINT 50 THRU 51 n $ Referenced Coordinate Frames n ENDDATA

58 S4-58 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5A COUPLED ADVECTION n Redo this problem with a smaller mesh element size of 0.1 inch. u 1/5 of previous element size n Compare the results for the previous thermal analysis(coarse mesh) with those for this analysis(fine mesh)

59 S4-59 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5A COUPLED ADVECTION n The temperature contour is for the finer mesh model.

60 S4-60 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5A COUPLED ADVECTION n For the finer mesh model the fluid temperature rises from 20 degrees(at the inlet) to 35.5 degrees(at the outlet).

61 S4-61 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5A COUPLED ADVECTION 0 SUBCASE 1 LOAD STEP = E+00 T E M P E R A T U R E V E C T O R POINT ID. TYPE ID VALUE ID+1 VALUE ID+2 VALUE ID+3 VALUE ID+4 VALUE ID+5 VALUE 1 S E E E E E E+01 7 S E E E E E E S E E E E E E S E E E E E E S E E E E E E S E E E E E E S E E E E E E S E E E E E E S E E-03 Extract from MSC.Nastran ASCII Results File

62 S4-62 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5A COUPLED ADVECTION n It is seen the fluid exit temperature is degrees S E E E E E E S E E E E E E S E E E E E E S E E E E E E S E E E E E E S E E-03 Extract from MSC.Nastran ASCII Results File

63 S4-63 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5A COUPLED ADVECTION n Energy balance u Delta T = Q/(Mdot*Cp) Where Q = total heat Mdot = mass flow rate Cp = specific heat for the fluid u T exit = T in + Q/(Mdot*Cp) = 20 +(20)*(3)/( *456.2) = 35.78

64 S4-64 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation PROJECT 5A COUPLED ADVECTION LOAD STEP = E+00 H E A T F L O W I N T O H B D Y E L E M E N T S (CHBDY) ELEMENT-ID APPLIED-LOAD FREE-CONVECTION FORCED-CONVECTION RADIATION TOTAL E E E E E E E E E E E E E E E+00 Extract from MSC.Nastran ASCII Results File n Energy loss(transfer) by convection

65 S4-65 NAS104, Section 4, March 2004 Copyright 2004 MSC.Software Corporation n Perform Workshop 5 Axisymmetric Flow in a Pipe in the exercise workbook. n Perform Workshop 6 Typical Avionics Flow in the exercise workbook. n Perform Workshop 7 Thermal Contact Resistance in the exercise workbook. EXERCISES