An MSC.Nastran Primer for Rotordynamics. Chuck Lawrence NASA Glenn Cleveland, Ohio

Transcription

1 An MSC.Nastran Primer for Rotordynamics Chuck Lawrence NASA Glenn Cleveland, Ohio

2 MSC.Nastran Rotordynamics Damage Resulting from Blade-Out

3 MSC.Nastran Rotordynamics Types of Analyses Engine performance critical speeds whirl forced response (unbalance, cabin noise) damping Static Analysis (external loads, maneuver loads) Transient blade off structural system response windmilling

4 MSC.Nastran Rotordynamics Typical Structural Model Engine Static Structure

5 MSC.Nastran Rotordynamics Background 1998 Meeting with engine and airframe manufacturers and MSC.Software All manufacturers performing similar types of analysis All manufacturers using similar, but self developed and maintained, software tools Common need to develop standardized analysis tools

6 MSC.Nastran Rotordynamics Participants Boeing Commercial Airplane Group Pratt & Whitney General Electric Aircraft Engines Rolls Royce Ohio Aerospace Institute MSC.Software NASA

7 MSC.Nastran Rotordynamics Process Form Working Group Define General Program Plan, Benefits and Advocacy Package Secure Funding Develop Boeing Document Bring MSC.Software Aboard Develop Software Requirements Document Develop Software Validate Software Phase II

8 MSC.Nastran Rotordynamics Unique Features General Finite Element Capabilities Component Substructuring Condensation of 3D Rotors Rotor Damping Non-Constant Rotor Speed Complex Mass Unbalance Fan-Case Interactions Multi-Spool Rotors Maneuver Loads Parametric Excitations

9 Primer Table on Contents I. Single Spool Rotor 1. Geometry 2. Gravity Loads 3. Maneuver Loads 4. Transient Unbalance Response 5. Synchronous Vibration (Critical Speeds) 6. Asynchronous Vibration (Whirl Analysis) 7. Comparison of Damping Models II. Dual Spool Rotor 1. Geometry 2. Synchronous Vibration (Critical Speeds) 3. Asynchronous Vibration (Whirl Analysis) 4. Transient Unbalance Response III. Squeeze Film Damper IV. Three Dimensional Model Reduction

10 Single Spool Rotor With Rotor and Support Damping Disk Unbalance Load (104) (105) Rigid Shaft Rotation Vector Support Damper Support Springs Rotor Damper Z Y X

11 1 $ 2 $ ROTOR DYNAMICS SAMPLE PROBLEM 3 $ SINGLE ROTOR, UNBALANCE LOAD 4 $ 5 6 ID SAMPLE ROTOR 7 SOL DIAG 5, 8, 56 9 CEND RGYRO= TSTEP= SET 500 = DISPLACEMENT(PUNCH) = BEGIN BULK UNBALNC, 111, 100.0, 102, 0., 1., 0., 19, 1.0, 0.0, 0.0, 0.0,, NONE 20 TSTEPNL, 100, 40000, 1.E-3, $ 23 $ ROTOR 1 24 $ Single Spool Rotor Transient Analysis 26 ROTORG THRU RSPINT, 10, 101, 102,, RPM, TABLED1, , 0.0, 800., 100.0, 800., ENDT GRID, 101,, 0., 0., GRID, 102,, 1., 0., 0.,, GRID, 103,, 2., 0., GRID, 104,, 0., 0., GRID, 105,, 2., 0., RBE2, 1001, 102, , 101, RBE2, 1002, 101, , RBE2, 1003, 103, , CONM2, 1004, 102,, 50., 42, 5.0,, 15.0,,, CELAS1, 1005, 1000, 104, 2 45 CELAS1, 1006, 1000, 104, 3 46 CELAS1, 1007, 1000, 105, 2 47 CELAS1, 1008, 1000, 105, 3 48 PELAS, 1000, 1.0E+5, ENDDATA

12 Single Spool Rotor Transient Response

13 Single Spool Rotor - Critical Speeds 1 $ 2 $ ROTOR DYNAMICS SAMPLE PROBLEM 3 $ SINGLE ROTOR, CRITICAL SPEEDS 4 $ 5 6 ID SAMPLE ROTOR 7 SOL DIAG 5, 8, 56 9 CEND RGYRO= DISP = ALL 13 CMETHOD = BEGIN BULK EIGC, 100, CLAN, 18, 0., 0.,,,,, RGYRO, 111, SYNC, 10, RPM, 0., $ 22 $ ROTOR 1 23 $ ROTORG THRU RSPINR, 10, 101, 102,, RPM, GRID, 101,, 0., 0., GRID, 102,, 1., 0., 0.,, GRID, 103,, 2., 0., GRID, 104,, 0., 0., GRID, 105,, 2., 0., RBE2, 1001, 102, , 101, RBE2, 1002, 101, , RBE2, 1003, 103, , CONM2, 1004, 102,, 50., 39, 5.0,, 15.0,,, CELAS1, 1005, 1000, 104, 2 42 CELAS1, 1006, 1000, 104, 3 43 CELAS1, 1007, 1000, 105, 2 44 CELAS1, 1008, 1000, 105, 3 45 PELAS, 1000, 1.0E+5, ENDDATA

14 Single Spool Rotor Campbell Diagram and Critical Speeds 2/rev 1/rev Mode 4 Third Critical First Critical Second Critical Mode 3 Mode 1,2

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16 Dual Spool Rotor Asynchronous Vibration 1 $ 2 $ ROTOR DYNAMICS SAMPLE PROBLEM 3 $ Dual Spool Rotor, Asynchronous Vibration 4 $ 5 6 ID SAMPLE ROTOR 7 SOL DIAG 5, 8, 56 9 CEND RGYRO = DISP = ALL 13 CMETHOD = BEGIN BULK RGYRO, 300, ASYNC, 20, FREQ, 0., 100., EIGC,100,CLAN, 20, 0., 0.,,,,, $ 23 $ ROTOR 1 24 $ ROTORG THRU RSPINR, 10, 101, 102,, FREQ, 20., 25., 35., 28, $ 53 $ ROTOR 2 54 $ ROTORG THRU RSPINR, 20, 201, 202,, FREQ, 10., 20., 30., 58, ENDDATA

17 Dual Spool Rotor Relative Rotor Speeds

18 Dual Spool Rotor Campbell Diagram and Critical Speeds 1/rev 6th Critical Mode 6 5th Critical Mode 5 1 st & 2nd Critical 3 rd & 4 th Critical Mode 3,4 Mode 1,2

19 Dual Spool Rotor Transient Response

20 Squeeze Film Damper

21 MSC.Nastran Rotordynamics Summary Unified front and team effort enabled rotordynamics to be implemented into MSC.Nastran Rotordynamics primer is available for distribution MSC.Software did an outstanding job of satisfying customer s needs