PAT312, Section 27, December 2006 S27-1 Copyright 2007 MSC.Software Corporation SECTION 27 CAPABILITIES AND FEATURES OF MSC.THERMAL. - презентация

1 PAT312, Section 27, December 2006 S27-1 Copyright 2007 MSC.Software Corporation SECTION 27 CAPABILITIES AND FEATURES OF MSC.THERMAL

2 PAT312, Section 27, December 2006 S27-2 Copyright 2007 MSC.Software Corporation

3 PAT312, Section 27, December 2006 S27-3 Copyright 2007 MSC.Software Corporation HEAT TRANSFER MODELING CAPABILITY l Conduction heat transfer l Constant, variable and non-linear material properties l Accurate in skewed meshes and with 3D orthotropic materials l Convection heat transfer l Constant, variable and non-linear convection coefficients l Library of 57 convection configurations l Various geometric configurations l Laminar and turbulant flows with calculated transitions l Natural and forced convection l Pool boiling and condensation l Contact resistance with an interstitial fluid

4 PAT312, Section 27, December 2006 S27-4 Copyright 2007 MSC.Software Corporation HEAT TRANSFER MOELING CAPABILITY (Cont.) l Radiation heat transfer l Constant, variable and non-linear emissivity and transmissivity l Gray and wavelength-dependent radiosity networks l Built-in viewfactor program l Advection heat transfer l Constant, variable and non-linear mass flow l Gap or contact heat transfer

5 PAT312, Section 27, December 2006 S27-5 Copyright 2007 MSC.Software Corporation FLUID FLOW MODELING CAPABILITY l One dimensional incompressible potential flow l Hydraulic and coupled hydraulic/thermal l Flow networks l Model generalized parallel/series flow paths l Couple to thermal solution l Library of components (flow element properties) l General head-loss or control valve l Check valve l Turbine l Pump l Pipe l Constant, variable or non-linear fluid properties l Specify or calculate friction factor (Moodys equation) l Constant or variable pressure and mass-flow boundary conditions

6 PAT312, Section 27, December 2006 S27-6 Copyright 2007 MSC.Software Corporation FINITE ELEMENT MODELING FEATURES l Element library l 2D, 3D and axisymmetric bar-2, tri-3 and quad-4 elements l 3D tet-4, wedge-6 and hex-8 elements l Material properties support l Define within MSC.Patran l Constant, variable and non-linear material properties l Fixed value entry l Tabular entry l Library of analytical functions (material property field) l Define directional dependence l Unlimited phase changes

7 PAT312, Section 27, December 2006 S27-7 Copyright 2007 MSC.Software Corporation FINITE ELEMENT MODELING FEATURES l Predefined database contains 970+ thermal material property sets l Database contains temperature dependent tabular data for: l Thermal conductivity l Specific heat l Density l Latent heats l Cross-reference MID/Material names with MSC.Patran Utilities l Text version of data available in $P3_HOME/p3thermal_files/lib l Provided in 4 systems of units, mks, cgs, fph and ips l Customize or add database using the PATQ utility

8 PAT312, Section 27, December 2006 S27-8 Copyright 2007 MSC.Software Corporation ANALYSIS CAPABILITIES l Available solution type: l Transient solution l Steady-state solution l Coupled hydraulic/thermal solutions l Thermal radiation viewfactors and resistors l Sequential steady-state and transient solution combinations l Optional restart from existing results file

9 PAT312, Section 27, December 2006 S27-9 Copyright 2007 MSC.Software Corporation ANALYSIS CAPABILITIES l Solution algorithms l Unconditionally stable implicit predictor/corrector for transient l Adaptive time-stepping by default l Strongly Non-linear Point Successive Over Relaxation (SNPSOR) solver for systems of implicit transient and steady state equations l Hybrid Newtonian first order/second order adaptation l First order in conduction terms, second order in all other terms l Automatically switches to bisection method near phase change to prevent oscillation l Selectable conduction term update frequency for weakly non-linear conduction problems l Adaptive relaxation parameter estimation by default l Direct solver for small linear or stiff problems l Modified Choleskis method l Can be run in combination with SNPSOR solver for improved non-linear performance l Convergence based on evaluation of total residual delta-T

10 PAT312, Section 27, December 2006 S27-10 Copyright 2007 MSC.Software Corporation OUTPUT FEATURES l Select an output temperature scale l Independent from analysis and initial temperatures l Automatically convert FEM geometric units l Select or stage the output intervals l Select an output interval for steady state iterations l Stage interval by time table for transient solutions l Define a subset of nodes for output data l Select among available nodal result quantities l Select among available diagnostic data l Integrated network translator selections l Output a SINDA deck l SINDA/G (BCD format) l SINDA 85 (HEADER) format

11 PAT312, Section 27, December 2006 S27-11 Copyright 2007 MSC.Software Corporation THERMAL RADIATION INTERCHANGE l Fully integrated into MSC.Thermal l Uses the same Patran model l 2D, 3D and RZ compatible l Multiple symmetry support l Evaluates obstructions l Allows multiple enclosures l Evaluates viewfactors to an ambient node l Models energy absorption by a participating medium l Adaptive integration order l Flag convex surfaces and obstructions l Viewfactors are reusable when material properties change l Optional collapse of redundant radiosity nodes

12 PAT312, Section 27, December 2006 S27-12 Copyright 2007 MSC.Software Corporation FINITE DIFFERENCE TECHNIQUE Element Centroidal l Element volumes are collapsed to discrete lumped mass nodes l Heat must flow along orthogonal lines between nodes l No mechanism for defining heat flow within an elemental volume l Conductors between nodes are directly computed from physical and material properties

13 PAT312, Section 27, December 2006 S27-13 Copyright 2007 MSC.Software Corporation FINITE ELEMENT TECHNIQUE l Heat flow is accounted for within an element l Conductors are defined among all nodes in each element l Conductors are derived from exact mathematical expressions for element (element formulations) l MSC.Thermal uses a Galerkin element formulation

14 PAT312, Section 27, December 2006 S27-14 Copyright 2007 MSC.Software Corporation A KERSHAW PROBLEM l Difference between Element Centroidal and Finite Element Networks l Element Centroidal results retain artifacts of mesh geometry l Finite Element network results are independent of mesh geometry

15 PAT312, Section 27, December 2006 S27-15 Copyright 2007 MSC.Software Corporation CPU TIMES FOR A NONLINEAR IRON CUBE Model Assumptions: T(Y=0) = Fixed at 0.0 C T(Y=1.0) = Fixed at C Vertical Sides Insulated T Initial, Interior = 0.0 C Steady state Cube FEM nodal dimension: A) 5 x 5 x 5 Nodes = 125 Nodes B) 11 x 11 x 11 Nodes = 1331 Nodes C) 21 x 21 x 21 Nodes = 9261 Nodes D) 31 x 31 x 31 Nodes = Nodes E) 41 x 41 x 41 Nodes = Nodes

16 PAT312, Section 27, December 2006 S27-16 Copyright 2007 MSC.Software Corporation BETA AND THE HUGHES' METHOD Midpoint RuleHughes Method For Engineering purposes, answers are not very sensitive to b as long as the solution remains stable. If you give b > zero, QTRAN will pick an "optimum" b for each node. This usually runs significantly faster. (b < zero fixed) Trapezoid Rule Crank-Nicholson

17 PAT312, Section 27, December 2006 S27-17 Copyright 2007 MSC.Software Corporation ROCKENBACH STRING COMPUTER (Point Iterative Gauss Seidel Relaxation)

18 PAT312, Section 27, December 2006 S27-18 Copyright 2007 MSC.Software Corporation CONVERGENCE CRITERION l MSC.Thermal converges based on estimated total residual error l Typically yields an order of magnitude smaller iterative error l Other codes converge based on iterative error threshold r = convergence factor As r 1.0, curve becomes flat and |Error| becomes small while |Error| can remain large

19 PAT312, Section 27, December 2006 S27-19 Copyright 2007 MSC.Software Corporation Q/TRAN'S HYBRID EXPLICIT/IMPLICIT TRANSIENT INTEGRATION SCHEME b > 0 For given DT, some nodes may be stable (while some may not be). For an explicit scheme for each node IF DT zero. ( b I)

20 PAT312, Section 27, December 2006 S27-20 Copyright 2007 MSC.Software Corporation RELAXS, RELAXT, & CPU TIMES 0 Gauss-Seidel W OPT C P U T i m e Under Relaxation Over Relaxation

21 PAT312, Section 27, December 2006 S27-21 Copyright 2007 MSC.Software Corporation SUMMARY OF FEATURES l MSC.Thermal is loaded with capability l Includes popular translators l Includes thermal radiation interchange algorithms l MSC.Thermal produces an accurate Finite Element based nodal network l MSC.Thermal solution routines are highly evolved l Provides several solvers l Provides flexibility by access to control parameters l Tuned to large non-linear problems l Faster and more accurate convergence than other codes l Seamlessly coupled to MSC.Patran modeling and results display capabilities

22 PAT312, Section 27, December 2006 S27-22 Copyright 2007 MSC.Software Corporation

23 PAT312, Section 27, December 2006 S27-23 Copyright 2007 MSC.Software Corporation

24 PAT312, Section 27, December 2006 S27-24 Copyright 2007 MSC.Software Corporation