Design, Analysis and Manufacturing Success w/NX...•Pilatus PC-24 Forward - looking -aft Aft...

transcript

Siemens PLM Connection 2016

Orlando, FL • May 16-19

www.plmworld.org #PLMCONX

Design, Analysis and

Manufacturing Success w/NX

Gordon Pfeiffer | ATA Engineering

gordon.pfeiffer@ata-e.com

ATA Engineering 35+ years of complete, integrated solutions

Structural, fluid,

acoustic, and

thermal analysis

services

Analysis Structural test

services for

extreme loading

environments

Test Concept

development to

detailed structural

design

Design

7 nationwide locations with full-service capabilities and customer support

An employee-owned small business with 100+ degreed engineers

#PLMCONX • www.plmworld.org

NASA SBIR Topic:

Deployable Engine Air-Brake for Drag Management Applications

Deployable Engine Air Brake (Patent Pending)

#PLMCONX 2016 | CONCURRENT DESIGN, ANALYSIS AND MANUFACTURING SUCCESS IN NX | PFEIFFER (ATA ENGINEERING)

• Swirls exhaust flow, which generates pressure drag

• Enables slower, steeper, or acoustically cleaner approach or descent when engine thrust can not be further reduced

What is an EAB (Engine Air Brake)?

What is “quiet” drag worth (constant-speed, steep approach)?

Selected commercial & bizjets aircraft size classes

(Values Inferred from Open Lit.)

+1º (3º 4º)

+3º (3º 6º)

Model Ref. Vapp

(m/s)/(kts) MLW (kg)

Afan (m2) (circ)

Fan Area CD,eq

CJ4 61.7/120 15,500 0.64 0.80 2.41

737-700A 66.4 / 129 58,000 3.77 1.01 3.04

HWB* 70.6/137 163,444 11.56 0.79 2.38

787-8 72.0 / 140 166,000 12.49 0.72 2.17

777-200ER 71.1 / 139 213,000 15.33 0.80 2.40

* M.S. Thesis, P. Weed (MIT), N2A

net baseline system net swirling

D equivalent

CD,eq = Drag metric in terms of engine cross-

sectional area -2.5 dB overall (under flight path)

-6 dB overall (under flight path)

Williams Int’l. FJ44-4

• Medium-bypass, 2-spool engine

• Full length bypass duct + exhaust mixer

• Dry weight of ~ 650 lb

• Airplanes with the FJ44-4 engine:

• Cessna CJ4

• Hawker 400XPR

• Pilatus PC-24

Forward-looking -aft

Aft-looking -forward

Stowed Deployed

Phase I

Phase II

Forward-looking -aft

Aft-looking -forward

Stowed Deployed

Phase I

Phase II

• Meets drag target by reducing gross thrust by 15%

• Meets stow/deploy time requirements (0.5 sec/ 3-5 sec)

• Flow capacity recovered at full deployment

Picture courtesy of Williams International

Key Requirements for full-scale ground engine test Oct 5-12, 2015 at Williams International (Walled Lake, MI)

Design activity involves multiple disciplines to address requirements

Aero Performance (CFD)

•Thrust reduction (drag)

•Adequate flow margin

(stowed/deployed/partial)

Structures

•Strength and fatigue at Temperature

•Natural frequency & stiffness

•Material selection for thermal

environment

Mechanical Systems

•Deployment time

•Stow time for go-around

•Packagable within notional flight

engine cowl

•Icing margin

Acoustics

•Minimize noise signature

Parametric Solid Modeling allowed rapid generation of designs with varying parameters • Used NX to create CAD bodies for CFD

• Used CFD results to update parameters and iterate on NX design

• A little more effort into building the initial model makes it more efficient

#PLMCONX 2016 | CONCURRENT DESIGN, ANALYSIS AND MANUFACTURING SUCCESS IN NX | PFEIFFER (ATA ENGINEERING) 10

Designs parameters

studied with CFD:

• Vane count (N)

• Swirl angle (S)

• Deployment rotation angle (R)

• Chord length (L)

• Cutout (area relief) depth (C)

Area Relief (Cutout) Depth

Swirl Angle

Chord Length

Deployment

Rotation

Aerodynamic Computational Methods

Mixing Plane

Interface

Periodicity

Freestream

Fan (Bypass)

Core Inlet

Freestream

Boundary

Downstream

Boundary

Computational Physics Models in STAR-CCM+:

Air (Ideal Gas), Coupled Flow & Energy

RANS CFD, k-w SST (Menter), “All y+ wall treatment”

Inflow BC’s: Uniform Flow, Pt, Tt specified

Default Turbulence: 1% Intensity, TVR=10

NX Expressions govern different parameters of

the model…

Airfoil sketch

Number of vanes

Vane rotation

Swirl angle

Hopefully the feature

tree updates

successfully when you

make a change…

150 CFD simulations later…

Vane count 12

Vane swirl angle 34º

Vane full deployment rotation angle 100º

Leading edge sweep angle 35º

Vane chord length at root (OD) 213 mm (8.39 in.)

Vane chord length at tip (ID) 248 mm (9.76 in.)

Vane area relief cutout depth (percent of local chord) 70%

How to fit a lot of mechanism in

a narrow amount of space (CJ4

cowl) “Allowable zone” (green)

Inside profile must be identical

to a blank nozzle when vanes

are stowed

Getting 12 vanes in sync

Mechanical Design Challenges:

Limited room for shaft inside vane and Nozzle

5/8”

9/16”

7/16”

1/2” R.125”

Min. clear

= 0.080”

Boolean ops created nozzle cavity shape

Revolve (by rotation angle ~ 100 deg)

Nozzle cutout increases flow despite blockage

•Cutout material subtracted from the Nozzle and added to the vane

•Smooth fairing added to vane

•Deployed vane – more nozzle exit area, flow

•Stowed vane – smooth inner mold lines without steps or gaps

vane with cutout added

vane with smooth

fairing to cutout

nozzle

cutout nozzle with vane deployed nozzle with vane stowed

Preliminary

ideas for

deployment

mechanism…

Solid model

with assembly

constraints…

Shows you how

the parts will

really interact

Solid model

with assembly

constraints…

Helps you

check for

interference

between parts

Solid model

with assembly

constraints…

Makes good

visuals

Key Hardware Components (1)

Key Hardware Components (2)

Analysis driven design used to define final configuration

• Aerodynamics • RANS CFD for performance • RANS CFD for gap leakage analysis • Conjugate HT for thermal • LES for unsteady loads

• Structures • FEA: Static Stress / Modal / Random / Sine • Fatigue • Thermal/structural deformation • Hand calcs

Finite Element Model enables many analyses

• Assembly FEM Contains Multiple Components • Nozzle, Vane, Shaft, Fasteners, Dogleg, Shaft Bushings

• Parabolic Tetrahedral Element Mesh • Small element size, 2 elements thru thickness

• Cyclic symmetry boundary condition allows 1/12 sector model

• Loads • Static pressure, temperature, sine & fluctuating press.

Analysis driven design:

Increased fillets in areas due to sine response stress

Contact + Preload models useful for sizing thread inserts (and determining they were necessary)

Nozzle areas

refined to

improve

strength and

stiffness

TempMap contour plotted in NX to verify hot vane will fit in cold nozzle for fast stow

Manufacturing:

How to machine this big nozzle?

• 1 huge part or 12 small ones bolted together? Tradeoffs

NX Drafting:

How to avoid intense dimensioning with a “reduced dimension drawing” note

NX Drafting: We only explicitly dimensioned the holes and other critical features

• Indicated various tolerance zones with notes

• Mixed end result from manufacturing

NX Drafting:

Large aluminum

nozzle was a

challenge to

machine on the 5

axis mill

Long thin areas

vibrate and

deform under

machining loads

Additional hand work done to bring nozzle up to spec

Clamped ring

for bake

Lapping

compound

Vane masked

for Hysol

gap fill

Many sensors gathered data during ground test

Channel Description

mic 1, 90° mic 2, 82° mic 3, 74° mic 4, 66° mic 5, 58° mic 6, 50° mic 7, 42° mic 8, 34° mic 9, 26° mic 10, 18° nozzle tip accel X nozzle tip accel Y nozzle tip accel Z nozzle base accel X nozzle base accel Y nozzle base accel Z string pot A string pot B linkage LC 01 linkage LC 02 linkage LC 03 nozzle strain, vane fillet nozzle strain, ram inline nozzle temp, tip nozzle temp, center nozzle temp, valley nozzle temp, spring nozzle temp, clamp linkage temp pump temp

Ground Testing of EAB on an Engine has been successful

• Drag target successfully met

• Flow/operability targets successfully met

• Noise favorable compared to analysis

• Dynamic deploy and stow demonstrated

• Fuel burn reduction

• Thermal environments within predicted limits

• No structural dynamic concerns on prototype

Questions?

Picture provided by Williams International

#PLMCONX • www.plmworld.org

Thank You!

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For more information on the EAB please visit our press release

Design, Analysis and Manufacturing Success w/NX...•Pilatus PC-24 Forward - looking -aft Aft...

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