The NASA High-Lift CRM: Geometry Models For GMGW-1 & HLPW-3

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Roy Hector Bailey
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1 The NASA High-Lift CRM: Geometry Models For & HLPW-3 Nigel Taylor MBDA UK Ltd Bill Jones NASA Langley Research Center Mark Gammon International TechneGroup, Inc. 1 st AIAA Geometry & Mesh Generation & 3 rd AIAA High Lift Prediction Workshops Denver, 3-4 June Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

2 Model Preparation (1/4) Objectives: To develop a reference geometry model to be used in (& HLPW-3) To make this available to workshop participants in a number of commonly used formats Process outline: Model aerodynamic design described in AIAA Pre-workshop data supplied in STEP format The intent was, as far as possible, to use data as supplied i.e. without modification or clean-up -> discover any matters arising via the workshops In the event, some modifications were made All modifications and final model assembly were undertaken using Siemens NX v8.5 The following (default) geometric tolerances were used throughout: Distance: 0.001inch; Angle: 0.5 Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

Element Protrusion Removed Slat Gap Filled with

3 Model Preparation (2/4) Removal of Nacelle/Pylon Assembly Main Element Protrusion Slat Gap Main Element Protrusion Removed Slat Gap Filled with Continuous Loft Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

6 Initial Observations on NX Model Topology Consists of 66 surfaces 12 of which are analytical (planes, cylinders) Underlying Parameterisation Unexpectedly dense and non-uniform in several places Degree of NURBS: e.g. slat (5) greater than elsewhere (3) Localised undulations in surface curvature are also present in several places Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

7 NX Model: Underlying Parameterisation (1/3) Forward region of belly-fairing & local fuselage interface Fold in NURBS at vertex. Size of fold ~0.1inch Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

10 Initial Observations on Derived Models Derived Models Open Formats: IGES, STEP (Parasolid not yet investigated) Proprietary MCAD: CATIA (CREO not yet investigated) None of the Derived Models are identical to the NX Model Variations in model translation can arise in either (or both) upstream and downstream tooling The following slides highlight some of the differences observed with the STEP & IGES models and when using CATIA Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

04mm) Underlying Parameterisation Same overall number of edges (334) as Native

11 STEP Model Native topology retained 66 surface patches Watertightness Max sloppiness between bounding curves ~1.47e-3in (0.04mm) Underlying Parameterisation Same overall number of edges (334) as Native Model Note detail around slat and (3x3) approximation of NX offset surface Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

IGES Model Native topology not retained Trim curves more fragmented 10 surfaces un-trimmed (slat & belly fairing) Does contain offset surfaces NB NX IGES export does not

12 IGES Model Native topology not retained Trim curves more fragmented 10 surfaces un-trimmed (slat & belly fairing) Does contain offset surfaces NB NX IGES export does not support IGES type 143/141 entities Re-work required to re-discover lost connectivity Downstream software/user dependant Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

CATIA Model (NX does not export CATIA models) Difficulties encountered importing STEP file directly into CATIA v5 End result (illustrated) highlights problems with central fuselage and slat regions

13 CATIA Model (NX does not export CATIA models) Difficulties encountered importing STEP file directly into CATIA v5 End result (illustrated) highlights problems with central fuselage and slat regions Arise because of checks for C2 continuity undertaken in CATIA (surfaces are split where this is not maintained -> extra work required to prepare for meshing) NB: There may be differences between the C2 checks/ mods made in CATIA itself and in the CATIA API [TBC] Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

14 Closing Remarks (1/2) A suite of geometry models of the HL-CRM have been prepared for and HLPW-3 Judging from initial analyses, the models supplied have been improved in several respects from those made available for previous AIAA workshops Underlying topology; connectivity However, several regions of the NX model exhibit unexpected and undesirable features, e.g. Dense, irregular underlying parameterisation Localised variations in C2 continuity Moreover, none of the Derived Models are identical to the NX Model NB: No participant reported using the Native NX model as the starting point in their CFD process Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

15 Closing Remarks (2/2) Variations in model translation can arise in either (or both) upstream and downstream tooling COTS or bespoke Participant rendering of supplied models was not unique How important are the vagaries in the HL-CRM model definition? To what extent can we read this across to more complex (and constrained) models? Analysis continues A more comprehensive report will be made at AIAA SciTech in January To include analysis of participant data / experience provided at workshops (incl. correlations with flow solutions) Copyright MBDA UK Ltd & ITI Ltd. All Rights Reserved

Heat Transfer Modeling using ANSYS FLUENT

Lecture 7 Heat Exchangers 14.5 Release Heat Transfer Modeling using ANSYS FLUENT 2013 ANSYS, Inc. March 28, 2013 1 Release 14.5 Outline Introduction Simulation of Heat Exchangers Heat Exchanger Models