LINFLOW 1.4 1 The Company. LINFLOW 1.42 Why LINFLOW ? n Enables the Engineer to Efficiently: u Study of His/Her Design Dynamics, if the Structure is in.

LINFLOW 1.4

1The Company

LINFLOW 1.4 2

Why LINFLOW ?

Enables the Engineer to Efficiently: Study of His/Her Design Dynamics, if the

Structure is in Contact with an External and or Internal Fluid (such as any Gas or Liquid).

Study Internal and/or External Acoustics Generated by the Vibrating Design. This also when Taking into Account the Effect of a Non-Zero Mass Flow (e.g Wing Effect)

Predict Steady and Unsteady (Oscillating) Fluid Dynamics if Boundary Layers are Thin or have Small Influence on Overall Behavior.

An Efficient Complementary tool to Navier-Stokes Based Fluid Dynamic Solutionsand FE-based Structure Dynamics.

LINFLOW 1.4 3

Why LINFLOW Dynamics,1 Enable Study of Dynamics of the Design, When the Structure and the

Fluid is Considered as One Equation System. This is Called Aeroelasticity in Aeronautical Engineering.

In an Eigenvalue Solution Characteristic Frequencies and Mode Damping Characteristics will Depend on: Flow Velocity Fluid Pressure Level Gas/Liquid properties (Density etc.)

Courtesy of FläktWoods AB,Sweden

Instability

Flow Velocity Dependent Damping Characteristics

LINFLOW 1.4 4

Why LINFLOW Dynamics,2 LINFLOW Extends Classic Aeroelastic Methods

BAH (Bisplinghof, Ashley and Halfman) Wing. Transonic Jet Transport wing

Structural ModelAerodynamic Model

Description

LINFLOW 1.4 5

Why LINFLOW Dynamics, 3Pipe Example, Two Structural Mode Couple to Create a Fluid-elastic mode for the Structure with Internal Flow.

(Click on this Text for Animation)

Fan Example, Three Structural Modes Couple to Create a Fluid-elastic mode for the Structure with External Flow.

(Click on this Text for Animation) Description Description

Sub-Sea Example

Description

LINFLOW 1.4 6

Why LINFLOW Dynamics,4 Enable the Engineer to Study the Response of his/her Design due

to Structural and/or Fluid Dynamic Loading. Pressure in the Flow Field may Oscillate with Low and/or High Frequency and LINFLOW can then Calculate the Response of the Design.

Navier-Stokes Fluid Dynamics.

Time History of Pressure Up-streamthe Fan

Frequency Spectrum ofthe Pressure

LINFLOW Fluid Dynamics

Stress calc. location

Structural Response

Description

LINFLOW 1.4 7

Why LINFLOW Acoustics? Enables the Study of Internal or External

Acoustics Generated by the Vibrating Design. This also when Taking into Account the Effect of a Non-Zero Mass Flow (i.e Wing Effect)

Standard Acoustics of a VibratingTuning Fork.

Acoustics in Landscape Without Wind

Flow DirectionWind

Acoustics with Wind

LINFLOW 1.4 8

Why LINFLOW Fluid Dynamics ? Fast and Accurate Prediction of Steady and

Unsteady (Oscillating) Fluid Dynamics if if Boundary Layers are Thin or have Small Influence on Overall Behavior.

A Navier-Stokes Solution for the Flying Object

The LINFLOW Model

Velocity Field on the LINFLOW Model

CL and CD vs. AOA

-1.4

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0 5 10 15 20

AOA (deg)

CL

an

d C

D

CL LINFCD LINFCL EXPCD EXP

CL (Lift) and CD (Drag) Experimental Verification

Many Hours in Modeling and Solution.

Minutes in Modeling and Solution.

LINFLOW 1.4 9

Conclusions LINFLOW does:

Analysis of Dynamics Systems when the Structure is in Contact with an External and/or Internal Fluid (such as any Gas or Liquid).

Internal or External Acoustics Generated by the Vibrating Design, and May Include Flow Field Effects.

Steady and Unsteady (Oscillating) Fluid Dynamics.