MSC.Nastran™ Rotor Dynamics

• Simulate Rotor Dynamic Related Situations such as:– Imbalance Response and General Excitation.– Maneuver Loads.– Blade-Out Response.

• Calculate Critical Speeds and Whirl Frequencies.

• Predict Rotor Rubbing.

• Simulate Systems Involving Multiple Rotors.

• Model and Analyze Squeeze Film Damper Nonlinearities.– Model General Damper Orbits with

Broad Frequency Content.– Calculate Oil Film Forces by Numerical

Integration of Instantaneous Film Pressure Distribution.

• Available for 2-D and 3-D Models.

OVERVIEWSimOffice™ is a stand-alone environment in which engineers can build, test,review, and improve their designs. SimOffice gives product development engineers the shared technologies they need to assess product performanceand accelerate innovation.

The MSC.Nastran™ product family is modular, enabling you to analyze productsranging from simple components to complex structures and systems. This alsoenables you to start simply and to grow your analysis capabilities as your VirtualProduct Development (VPD) needs expand. As part of your VPD process, youcan use MSC.Nastran to assess many functional aspects of your products, suchas the structural response (displacement, strain, stress, vibration, andtemperature) due to its material properties and the loads and boundaryconditions that are applied to it during operation.

MSC.Nastran™ Rotor DynamicsThe MSC.Nastran™ Rotor Dynamics product module provides a simple method toperform the various tasks associated with the design and analysis of structureswith the dynamics of rotating components. The procedures were developed withinput from aerojet engine manufacturers to ensure that their stringentrequirements were met. In addition the aerojet engines, the rotating shafts,bearings, and seals of a steam and gas turbines, compressors, pumps, andcentrifuges can be analyzed to ensure stable, safe operation. Understand out of balance systems, determine system instability, detect imminent productfailure, and calculate safe operating ranges and conditions before the productsgo into service.

The rotor dynamic system, the rotor and rotor support for example, may bemodeled using any of the standard scalar, 2-D, and 3-D elements available inMSC.Nastran. The gyroscopic terms for a single rotor or multiple rotorsspinning at different rates are automatically added for response calculation.Rayleigh, structural (hysteretic), viscous, and modal damping terms can beincluded in the analyses. The destabilizing effect due to rotor damping can alsobe included. Standard post processing of results is supported.

Simulating the Effects of RotatingComponents for Design and Analysis

SimOffice™

Product FamilyMSC.Nastran™

PRODUCT LINE

Prototype Engine Model, Courtesy Boeing Aerospace

BENEFITS

CAPABILITIES

• Now Completely Integrated and Supported in MSC.Nastran Using Standard Solution Sequences – No DMAP Alters Needed.

• Proven Solution that Conforms to Stringent Aeroject Requirements and Industry Standards.

• Reduce Risk and Increase Opportunity Through Rapid Understanding of Rotating Machinery Performance Characteristics.

• Increase Product Stability and Eliminate Damage-Causing Vibration.

• Reduce Cost of Physical Prototyping and Test Through Virtual Simulation.

• Improve Performance and Safety Concerns.

• Eliminate Warranty, Repair, and Litigation Costs Associated with Product Failure.

• Meet Design Schedules with Accurate Prediction of Safe Operating Conditions.

Rotor Imbalance and General ExcitationYou can use frequency response analyses to determine therotor/support response to arbitrary excitation with the rotorsspinning at user-specified rates (ASYNC) or to excitation that issynchronous with the reference rotor (SYNC). The ASYNCcalculation determines the response of the system to an externalinput that is independent of the rotor speed. The SYNC calculationdetermines the system response to a rotor imbalance or otherexcitation that is dependent on the rotor spin rate.

Critical Speeds and Whirl FrequenciesComplex modes analyses determine whirl frequencies and criticalspeeds. Whirl modes are modes of a rotor/support system withthe rotors spinning at specified rates. Critical speeds are whirlfrequencies that coincide with a rotor spin rate. You can calculatewhirl frequencies with the asynchronous option (ASYNC) and criticalspeeds with the synchronous option (SYNC).

Maneuver LoadsStatic analysis determines the loads on the rotor due to pitch oryaw of an aircraft. Severe transverse rotations may be part of thedesign environment. Limiting rotor motion to prevent rotor bladesfrom rubbing against the interior of the casing may be part of thedesign criteria. This new feature can help you determine if apotential rub condition exists.

To find your local MSC.Software office or to learn more about our company and our products, please contact:

MSC, MSC., the MSC.Software corporate logo, Simulating Reality, SimOffice, and the names of theMSC.Software products and services referenced herein are trademarks or registered trademarks of theMSC.Software Corporation in the United States and/or other countries.

NASTRAN is a registered trademark of NASA. All other products names, brand names, or trademarks belong to their respective owners.

© 2005 MSC.Software Corporation. All rights reserved.NA*2004NOV*Z*ROTD*Z*LT-DAT

Customer Care Center:1 800 642.7437 (U.S. only)1 978 453.5310 (International)customer.care@mscsoftware.com

Worldwide Web - www.mscsoftware.comCorporate:MSC.Software Corporation2 MacArthur PlaceSanta Ana, California 92707 USATel: 1 714 540.8900Fax: 1 714 784.4056

Rotor Imbalance Response Plot

With Gyroscopic Terms

WithoutGyroscopic Terms

Res

po

nse

Rotor RPM

Response to Rotor Imbalance

C Center of Gravity of Rigid Disk

1.2E-02

1.0E-02

8.0E-03

6.0E-03

4.0E-03

2.0E-03

0 400 800 1200 2000 2400 2800 3200 36001600

0.0E+00

2 R

L

EI C

Blade-Out ResponseDirect linear and nonlinear transient analyses enable you tosimulate engine blade-out and subsequent wind milling conditions.The analysis is used to help you ensure structural integrity during flight by ensuring that excessive vibration levels will not be reached.

Squeeze Film DampersThe general squeeze film damper (SFD) model has beensuccessfully incorporated into MSC.Nastran time-domain analysisand this new capability provides the means to design and analyzeSFDs for general rotor orbits with multiple frequency content.The new capability includes static loads and models the lift-offphenomenon important to the design of free-floating dampers.

EXTEND YOUR INVESTMENTMSC.Software recommends MSC.Patran™ or MSC.SOFY™ for an integrated modeling and analysis environment.

MSC.MasterKey™ delivers a flexible, token-based licensing systemthat provides access to the breadth and depth of MSC.Software’sworld-class Virtual Product Development software portfolio,allowing you to use whatever simulation tools you want, wheneveryou need them – maximizing your productivity and reducing cost.

MAXIMIZE YOUR RETURN ON INVESTMENTMSC.Software provides the most comprehensive training,support, and professional services with offices worldwide toprovide local and centralized support. Investing in MSC.Softwaregives you access to extensive client support throughcomprehensive documentation, direct technical expertise, and customized onsite and offsite training classes taught byexperienced engineers.