MINIATURE ENGINEERING SYSTEMS GROUP

FUNDAMENTAL TECHNICAL ISSUESZero boil-off of cryogenic propellants such as lh2 in spaceCryocooler simultaneously optimized for Compactness, Light-weight, Reliability and High EfficiencyInnovative requirementAppropriate resultUsage of Reverse Turbo Brayton CryocoolersCompact, Light-weight, Reliable and Highly EfficientFeaturesNo unbalanced or reciprocating components

Proposed Technical SolutionsOptimal mixture of in-house technical innovation and selection of off-the-shelf technology where availableif notWe directly approached the corresponding best possible resource to have a solution in short span of time Gas foil bearingsRotordynamicsMotorGRCDr. Nagaraj Arakere, UFLMr. Jay vaidya,EAIPartnered w/ Rini Tech. Inc,. for fast product developmentFrequent communication w/cryogenic specialists at AFRL, NIST, ONR/DARPA,NASA KSC, NASA GRC and NASA Arc

Other Sources of Financial SupportNASA KSC Miniature Joule Thompson cryocooler, 2002-03NASA KSC CCDF (through ASRC) Miniature Joule Thompson cryocooler, 2003-04RTI Development of Miniature compressor and heat Exchanger 2002-03MDA SBIR (through AFRL) Development of a compact recuperator, Nov 02 May 03MDA SBIR (through AFRL) Design of a reliable turbo reverse Brayton cryocooler, Nov 03 - May 04NASA SBIR (JSC) - Development of a 77K Reverse-Brayton Cryocooler with Multiple Coldheads, March 04 Sep 04Pending

MDA SBIR Phase II (through AFRL) Design of a reliable turbo reverse Brayton cryocooler, summer 04MDA SBIR (through AFRL) Reliable and highly efficient multi-stage centrifugal compressor for low temperature cryocoolers, selected for Phase I award.MDA SBIR (through AFRL) MEMS fabricated, highly effective, compact recuperative heat exchanger for a miniature, reliable cryocooler, selected for Phase I award

PUBLICATIONSTwo-Stage Cryocooler Development for Liquid Hydrogen Systems, Joint Symposium of the Florida Society of Microscopy and the Florida Chapter of the American Vacuum Society, Orlando, FL, March 17-20, 2003.Two-Stage Cryocooler Development for Liquid Hydrogen Systems, Space Cryogenics Workshop, Alyeska Resort, AK, September 18-19, 2003.Design of a Super-High Speed PMSM for Cryocooler Application, Space Cryogenics Workshop, Alyeska Resort, AK, September 18-19, 2003.Mesoscopic Energy Systems, accepted to be published in Annual Review of Heat Transfer, 2004.Development of a Super-High Speed PMSM Controller and Analysis of the Experimental Results, to be presented at The Eighth World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2004), Orlando, FL, July, 2004.Development of a New V/f Control for a Super-High Speed PMSM, to be presented at The Eighth World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2004), Orlando, FL, July, 2004.Design and Simulation of a Cryogenic Electrical Motor, submitted to 2004 AP-S International Symposium and USNC/URSI National Radio Science Meeting, Monterey, California, June 20-26, 2004.

PUBLICATIONS 8) Design of a Super-High Speed Cryogenic Permanent Magnet Synchronous Motor, submitted to Eleventh International Power Electronics and Motion Control Conference (EPE-PEMC 2004), Riga, Latvia, September 2-4, 2004. (Invited paper: Special section about high and super-high speed motor). 9) Design of a Super-High Speed Axial Flux PMSM, submitted to IEE Proceedings on Electric Power Applications.10) Design and Preliminary Testing of a Compact, High Speed Centrifugal Compressor, submitted to ASME International Mechanical Engineering Congress and Exposition, 2004.11) Computational Analysis of a Compact, High speed Centrifugal Compressor, submitted to ASME International Mechanical Engineering Congress and Exposition, 2004.12) Design and Fabrication of a Compact Recuperative Heat Exchanger with High Effectiveness, submitted to ASME International Mechanical Engineering Congress and Exposition, 2004.13) Miniature Joule-Thomson (JT) Cryocoolers for Propellant Management, submitted to ASME International Mechanical Engineering Congress and Exposition, 2004.

PATENTS UNDER PREPARATION Compact, High Speed Centrifugal Compressor with High Efficiency.

Compact, Recuperative Heat Exchanger with High Effectiveness.

Compact, High Speed Permanent Magnet Synchronous Motor with High Energy Density and High Efficiency.

Cryogenic High Speed Motor.

Table of ContentsStatement of WorkOverall ViewSingle Stage Centrifugal Compressor TestingCFD SimulationBearing DesignDesign of Permanent Magnet Synchronous Motor and Control Electronics

Statement of WorkPhase I (15 months) July 1, 02 to September 30, 03Focused on the overall cryocooler design, and design and demonstration of the key enabling component (compressor), and development and characterization (at room temperature) of TiN, MoS2, TiN/MoS2 coatings.

Phase II (12 months) October 1, 03 to September 30, 04Considers testing and optimization of the compressor and motor, and design of other components (recuperator and gas foil bearing). The tribological coating developed in Phase I will be characterized at cryogenic temperature. Also, an ultra low coefficient-of-friction MoS2 coating will be developed.

SIGNIFICANCE OF MOTORCOOLING LOAD REQUIREMENT OF 50 W AT LH2 TEMPERATURECENTRIFUGAL COMPRESSOR MUST AT LEAST HAVE A DESIGN SPEED OF 200,000 RPM TO COMPENSATE FOR ITS SMALL SIZE (Utip D*N) AND TO COMPRESS A LIGHT GAS LIKE HELIUM (EVEN IF THE COMPRESSION PROCESS IS ACHIEVED IN FOUR STAGES)SolutionTo inevitably Design a High Efficient, Super High Speed Motor at lh2 temperature that is capable of rotating the four-stage compressor at 200,000 rpmcycle optimizationBASIS

Feb 23Year 2 Tasks & ScheduleTo continue with the single stage compressor simulation and testing and to verify its design.To design and check the fabrication feasibility of the four stage compressor.To fabricate and test the permanent magnet synchronous motor.To design and check the fabrication feasibility of high effectiveness micro channel heat exchanger.To design and develop gas foil bearing for the overall system.To develop and measure tribological properties for TiN/MoS2 and DLC/MoS2 bilayers at 77K.To achieve ultra low coefficient-of-friction MoS2 coating.

Overall View

Overall System

Four Stage Compressor Assembly Structure

Four Stage Compressor Rotating Part

MINIATURE SINGLE STAGE CENTRIFUGAL COMPRESSORtesting

Test SetupCompressorElectric MotorCoupler

Power Plot

149.663.226.8

28.518.3145.643.2

4040212.840.15

606233853.3

909054061.6

119129.7286868.25

174.4186.368.6

241.2255.370.7

29888

41888

516148.35

327.6

420

733.6

1108.8

1288

Cast Impeller

Straight Blade Impeller Test 1

Straight Blade Impeller Test 2

Straight Blade Impeller w/ Data Acquisition

Speed (rpm)

Power (Watts)

Power versus Speed

Pressure Plot

0.180.1350.450.457960510.29

0.4050.3151.2150.4598145

0.630.5851.8450.4605975

0.90.8552.7450.460044

1.3051.2153.4650.4604355

1.7551.533.780.46197

2.251.980.4617405

2.72.5650.4621095

2.8350.462339

3.1050.463923

3.3750.464022

0.465588

0.4659075

0.466533

0.467154

0.4680135

0.4676445

0.467532

0.466398

0.467334

0.468225

0.470592

0.4713075

0.4712175

0.4736655

0.4742865

0.474579

0.475812

0.4763115

0.4754115

0.475443

0.475101

0.4755825

0.477189

0.4782105

0.5048415

0.5532345

0.6450525

0.697266

0.7059825

0.7080345

0.709893

0.714033

0.7358715

0.767772

0.812628

0.818883

0.8204715

0.8351595

0.841698

0.8404425

0.83979

0.8508015

0.925029

0.9307845

0.9319995

0.9753705

0.962757

0.954459

0.95778

0.96039

0.959112

0.958392

0.9580005

0.956358

1.028394

1.1137545

1.140156

1.145421

1.1471985

1.1486385

1.1480805

1.147266

1.147761

1.1487195

1.1509245

1.1507355

1.151028

1.149534

1.1480805

1.14795

1.1505195

1.1541105

1.151649

1.152135

1.1536155

1.155051

1.1546775

1.1543175

1.157229

1.1584395

1.159083

1.1594835

1.156977

1.1561625

1.156185

1.1561355

1.157166

1.15857

1.1617695

1.1643975

1.1673495

2.00682

2.9470725

4.344804

5.0542965

Cast Impeller

Straight Blade Impeller Test 1

Straight Blade Impeller Test 2

Straight Blade Impeller w/ Data Acquisition

Design Point

Speed (rpm)

Gage Pressure (psig)

Gage Pressure Versus Speed

Mass Flow Plot

0.64938277622.11691975442.35672699822.0742589609

2.66969989252.65827883063.84886938272.1433279028

1.96852835983.57983657873.15912717272.4116764154

1.60754560911.64018539923.38876388632.8069802317

3.94631339354.55097434693.9523971752.8961683795

3.25851096542.4076771613.0739542015

2.79860609262.72718347523.11299615

3.12965522773.12084870273.1499616276

3.61535583473.343535684

3.86170264673.4546601343

3.5265250473

3.7205484047

3.7822032327

3.8177239014

1.2815452944

5.1388827975

Cast Impeller

Straight Blade Impeller Test 1

Straight Blade Impeller Test 2

Straight Blade Impeller w/ Data Acquisition

Speed (rpm)

Mass Flow (g/s)

Mass Flow versus Speed

Data

Test NumberDateTimePower SupplyTemperaturePressureOscilloscopeSpeedVolumetric Flow RateDensityMass Flow Rate

VoltageCurrentPowerMass Flow MeterDiffuserInlet Guide VaneDiffuserMass Flow MeterTime 1Time 2

(Volts)(Amperes)(Watts)(oC)(oC)(oC)(Volts)(psig)(Volts)(psig)(ms)(ms)rpmft3/seckg/m3g/sec

Test 4 Straight Blade Impeller with Data Acquisition9/16/036:11:00 PM25.51na25.670.6850.3830.7020.458nana265981.220

9/16/036:11:02 PM25.53na25.650.6850.3830.7020.460nana266611.220

9/16/036:11:04 PM6.74.026.825.53na25.650.6860.3860.7020.461nana266791.220

9/16/036:11:06 PM25.51na25.640.6860.3870.7020.460nana267361.220

9/16/036:11:08 PM25.51na25.630.6860.3880.7020.460nana267441.220

9/16/036:11:10 PM25.52na25.610.6860.3880.7030.462nana267571.220

9/16/036:11:12 PM7.26.043.225.52na25.670.6860.3880.7030.462nana267601.220

9/16/036:11:14 PM7.35.540.225.50na25.650.6860.3880.7030.462nana267971.220

9/16/036:11:16 PM8.26.553.325.49na25.610.6860.3890.7030.462nana268171.220

9/16/036:11:18 PM25.49na25.620.6870.3910.7030.464nana268561.220

9/16/036:11:20 PM25.50na25.680.6870.3920.7030.464nana268701.220

9/16/036:11:21 PM25.50na25.640.6870.3920.7030.466nana269071.220

9/16/036:11:23 PM25.49na25.640.6870.3930.7040.466nana269131.220

9/16/036:11:25 PM25.53na25.640.6870.3910.7040.467nana269261.220

9/16/036:11:28 PM25.51na25.650.6870.3930.7040.467nana269361.220

9/16/036:11:30 PM8.87.061.625.54na25.670.6870.3930.7040.468nana269721.220

9/16/036:11:32 PM9.17.568.325.54na25.630.6870.3940.7040.468nana269641.220

9/16/036:11:34 PM25.52na25.650.6880.3940.7040.468nana269681.220

9/16/036:11:36 PM25.51na25.670.6880.3940.7040.466nana269711.220

9/16/036:11:38 PM25.50na25.630.6880.3940.7040.467nana269911.220

9/16/036:11:40 PM25.50na25.640.6870.3930.7040.468nana270031.220

9/16/036:11:42 PM25.51na25.650.6880.3950.7050.471nana270391.221

9/16/036:11:44 PM25.52na25.710.6880.3960.7050.471nana270581.221

9/16/036:11:46 PM25.53na25.660.6880.3970.7050.471nana271251.221

9/16/036:11:48 PM9.87.068.625.53na25.710.6880.3970.7050.474nana271371.221

9/16/036:11:49 PM25.53na25.710.6890.3990.7050.474nana271951.221

9/16/036:11:51 PM25.52na25.700.6890.3990.7050.475nana272041.221

9/16/036:11:53 PM25.54na25.720.6890.4000.7060.476nana272401.221

9/16/036:11:55 PM10.17.070.725.54na25.700.6890.4010.7060.476nana272451.221

9/16/036:11:58 PM25.54na25.710.6890.4020.7060.475nana272581.221

9/16/036:12:00 PM25.55na25.720.6890.4020.7060.475nana272700.061.2212.074

9/16/036:12:02 PM25.55na25.750.6890.4020.7060.475nana272921.221

9/16/036:12:04 PM25.56na25.750.6890.4010.7060.476nana272890.0621.2212.143

9/16/036:12:06 PM25.57na25.720.6890.4030.7060.477nana273091.221

9/16/036:12:08 PM25.57na25.760.6900.4040.7060.478nana273261.221

9/16/036:12:10 PM25.59na25.720.6930.4170.7120.505nana275670.061.2232.078

9/16/036:12:12 PM25.59na25.710.7040.4690.7230.553nana284041.227

9/16/036:12:14 PM11.08.088.025.59na25.710.7220.5510.7430.645nana312560.0691.2342.412

9/16/036:12:16 PM25.63na25.640.7380.6190.7550.697nana324991.238

9/16/036:12:18 PM25.63na25.640.7400.6290.7570.706nana343041.239

9/16/036:12:19 PM25.66na25.710.7400.6320.7570.708nana343560.081.2392.807

9/16/036:12:21 PM25.67na25.670.7420.6370.7580.710nana344911.239

9/16/036:12:23 PM25.67na25.710.7420.6380.7590.714nana345341.240

9/16/036:12:26 PM25.67na25.710.7460.6580.7640.736nana348980.081.2412.812

9/16/036:12:28 PM25.69na25.700.7530.6860.7710.768nana352541.244

9/16/036:12:30 PM25.72na25.690.7640.7370.7810.813nana368940.0821.2472.896

9/16/036:12:32 PM25.71na25.660.7650.7450.7820.819nana371381.248

9/16/036:12:34 PM25.75na25.620.7660.7450.7820.820nana374460.0871.2483.074

9/16/036:12:36 PM25.80na25.620.7690.7580.7860.835nana375291.249

9/16/036:12:38 PM25.78na25.620.7700.7670.7870.842nana379511.249

9/16/036:12:40 PM25.78na25.610.7700.7660.7870.840nana379650.0881.2493.113

9/16/036:12:42 PM25.80na25.610.7700.7630.7870.840nana379691.249

9/16/036:12:44 PM25.83na25.610.7700.7660.7890.851nana379880.0891.2503.150

9/16/036:12:46 PM25.86na25.650.7880.8460.8060.925nana395351.256

9/16/036:12:48 PM25.86na25.630.7910.8600.8070.931nana398641.256

9/16/036:12:49 PM25.90na25.630.7910.8600.8070.932nana402590.0941.2563.344

9/16/036:12:51 PM25.91na25.630.7970.8860.8170.975nana404151.260

9/16/036:12:53 PM25.92na25.640.7990.8950.8140.963nana413541.259

9/16/036:12:56 PM25.94na25.660.7960.8830.8120.954nana411110.0971.2583.455

9/16/036:12:58 PM25.94na25.640.7970.8850.8130.958nana408571.258

9/16/036:13:00 PM25.94na25.620.7970.8850.8130.960nana408760.0951.2583.385

9/16/036:13:02 PM25.95na25.650.7960.8840.8130.959nana408971.258

9/16/036:13:04 PM25.98na25.640.7970.8850.8130.958nana408971.258

9/16/036:13:06 PM25.96na25.640.7960.8840.8130.958nana408890.0991.2583.527

9/16/036:13:08 PM26.03na25.620.7960.8830.8130.956nana408831.258

9/16/036:13:10 PM26.02na25.640.8100.9430.8291.028nana417200.1041.2633.721

9/16/036:13:12 PM26.07na25.640.8291.0290.8481.114nana426071.270

9/16/036:13:14 PM26.08na25.630.8371.0650.8531.140nana447970.1051.2723.782

9/16/036:13:16 PM26.10na25.630.8381.0720.8551.145nana449091.272

9/16/036:13:17 PM26.09na25.630.8381.0730.8551.147nana450831.273

9/16/036:13:19 PM26.14na25.610.8381.0730.8551.149nana450901.273

9/16/036:13:21 PM26.14na25.620.8391.0750.8551.148nana451160.1051.2723.783

9/16/036:13:23 PM26.18na25.620.8381.0730.8551.147nana451181.272

9/16/036:13:26 PM26.15na25.600.8391.0740.8551.148nana451280.1051.2723.783

9/16/036:13:28 PM26.18na25.620.8391.0750.8551.149nana451401.272

9/16/036:13:30 PM26.20na25.610.8401.0780.8561.151nana451940.1051.2723.783

9/16/036:13:32 PM26.19na25.610.8401.0790.8561.151nana452011.272

9/16/036:13:34 PM26.20na25.620.8401.0800.8561.151nana452061.272

9/16/036:13:36 PM26.22na25.630.8401.0780.8551.150nana452090.1051.2723.783

9/16/036:13:38 PM26.23na25.610.8391.0770.8551.148nana452051.272

9/16/036:13:40 PM26.27na25.630.8391.0780.8551.148nana452130.1061.2723.818

9/16/036:13:42 PM26.28na25.640.8401.0790.8561.151nana452331.272

9/16/036:13:44 PM26.28na25.610.8401.0790.8561.154nana452641.272

9/16/036:13:46 PM26.29na25.640.8391.0770.8561.152nana452850.1061.2723.818

9/16/036:13:47 PM26.34na25.660.8401.0780.8561.152nana452911.272

9/16/036:13:49 PM26.33na25.690.8401.0800.8561.154nana453240.1061.2723.818

9/16/036:13:51 PM26.32na25.700.8401.0800.8571.155nana453341.272

9/16/036:13:54 PM26.33na25.650.8401.0790.8571.155nana453361.272

9/16/036:13:56 PM26.35na25.670.8401.0790.8571.154nana453390.1061.2723.818

9/16/036:13:58 PM26.34na25.670.8401.0810.8571.157nana453701.272

9/16/036:14:00 PM26.36na25.700.8411.0840.8571.158nana453921.272

9/16/036:14:02 PM26.42na25.680.8411.0840.8581.159nana454281.272

9/16/036:14:04 PM26.37na25.670.8411.0840.8581.159nana454261.272

9/16/036:14:06 PM26.39na25.650.8411.0820.8571.157nana454101.272

9/16/036:14:08 PM26.37na25.630.8411.0830.8571.156nana454031.272

9/16/036:14:10 PM26.41na25.650.8401.0800.8571.156nana453921.272

9/16/036:14:12 PM26.41na25.630.8411.0830.8571.156nana453991.272

9/16/036:14:14 PM26.42na25.660.8411.0820.8571.157nana454031.272

9/16/036:14:16 PM26.44na25.680.8411.0830.8571.159nana454160.1051.2723.782

9/16/036:14:17 PM26.44na25.680.8421.0870.8581.162nana454781.272

9/16/036:14:19 PM11.08.088.026.47na25.650.8421.0870.8591.164nana455011.272

9/16/036:14:21 PM26.47na25.690.8421.0900.8591.167nana455970.061.2732.162

9/16/036:14:24 PM12.911.5148.426.52na25.780.9811.7151.0462.007nana485861.340

9/16/036:14:26 PM18.218.0327.626.69na25.701.2132.7601.2552.947nana689220.0321.4141.282

9/16/036:14:28 PM21.020.0420.027.02na25.731.4984.0411.5664.345nana755551.525

9/16/036:14:30 PM26.228.0733.627.66na25.891.6964.9321.7235.054nana939840.1151.5785.139

9/16/036:14:32 PM30.836.01108.8-116.26na29.191.6424.6901.4383.770nana95639

9/16/036:14:34 PM32.240.01288.0-84.66na218.151.5334.1991.3973.585nana97726

9/16/036:14:36 PM32.541.01332.5-134.36na-1000.001.3853.5340.107-2.219nana89841

9/16/036:14:38 PM33.140.01324.0-57.79na-1000.000.7950.8780.7860.835nana47561

9/16/036:14:40 PM-120.70na-1000.000.7180.5310.7160.524nana40523

9/16/036:14:42 PM-121.23na-1000.000.6590.2640.6640.286nana23512

9/16/036:14:44 PM-121.75na-1000.000.6310.1400.6390.176nana19787

9/16/036:14:45 PM-122.23na-1000.000.6160.0700.6250.115nana9884

9/16/036:14:47 PM-122.63na-1000.000.6090.0410.6200.092nana4468

9/16/036:14:49 PM-122.92na-1000.000.6080.0360.6200.089nana2745

9/16/036:14:51 PM-123.20na-1000.000.6080.0370.6200.090nana1008

9/16/036:14:54 PM-123.48na-1000.000.6080.0360.6200.089nana1017

Test 1 (Valve Full Open) with Cast ImpellerDateTimePower SupplyTemperaturePressureOscilloscopeSpeedVolumetric Flow RateDensityMass Flow Rate

VoltageCurrentPowerMass Flow MeterDiffuserInlet Guide VaneDiffuserMass Flow MeterTime 1Time 2

(Volts)(Amperes)(Watts)(oC)(oC)(oC)(Volts)(psig)(Volts)(psig)(ms)(ms)(rpm)(cfs)(kg/m3)(g/s)

8/19/03na4.03.514.023.1024.20na0.6300.1350.6400.1802601640144930.0191.2070.649

8/19/03na6.04.828.523.3024.60na0.6700.3150.6900.4052601114234190.0771.2242.670

8/19/03na8.05.040.023.6024.80na0.7200.5400.7400.630130768313480.0561.2411.969

8/19/03na10.06.060.024.0025.40na0.7900.8550.8000.900130654381680.0451.2621.608

8/19/03na12.07.590.024.9026.00na0.8701.2150.8901.305130560465120.1081.2903.946

8/19/03na14.08.5119.025.8026.60na0.9801.7100.9901.755130496546450.0871.3233.259

8/19/03na16.010.9174.427.7029.10na1.0902.2051.1002.25065388619200.0731.3542.799

8/19/03na18.013.4241.229.5030.50na1.1902.6551.2002.70065288.5894850.0801.3823.130

Test 2 (Valve Half Open) with Straight Blade ImpellerDateTimePower SupplyTemperaturePressureOscilloscopeSpeedVolumetric Flow RateDensityMass Flow Rate

VoltageCurrentPowerMass Flow MeterDiffuserInlet Guide VaneDiffuserMass Flow MeterTime 1Time 2

(Volts)(Amperes)(Watts)(oC)(oC)(oC)(Volts)(psig)(Volts)(psig)(ms)(ms)(rpm)(cfs)(kg/m3)(g/s)

9/3/03na4.02.49.622.5024.80na0.6200.0900.6300.13501400142860.0621.2062.117

9/3/03na6.13.018.322.8024.90na0.6600.2700.6700.3150862232020.0771.2192.658

9/3/03na8.05.040.023.2025.10na0.7200.5400.7300.5850630.4317260.1021.2393.580

9/3/03na10.06.262.023.7025.60na0.7800.8100.7900.8550501.6398720.0461.2591.640

9/3/03na12.07.590.024.3025.90na0.8601.1700.8701.2150423.2472590.1251.2864.551

9/3/03na14.19.2129.725.0026.80na0.9401.5300.9401.5300368543480.0651.3082.408

9/3/03na16.211.5186.326.5028.30na1.0502.0251.0401.9800322.8619580.0721.3382.727

9/3/03na18.513.8255.328.0030.20na1.1702.5651.1702.5650291.2686810.0801.3783.121

9/3/03na20.014.9298.029.6032.00na1.2302.8351.2302.8350268.874405na1.392na

9/3/03na22.019.0418.031.8033.50na1.2803.0601.2903.1050256.4780030.0911.4033.615

9/3/03na24.021.5516.032.6035.00na1.3503.3751.3503.3750239.2836120.0961.4213.862

Test 3 (Valve Half Open) with Straight Blade ImpellerDateTimePower SupplyTemperaturePressureOscilloscopeSpeedVolumetric Flow RateDensityMass Flow Rate

VoltageCurrentPowerMass Flow MeterDiffuserInlet Guide VaneDiffuserMass Flow MeterTime 1Time 2

(Volts)(Amperes)(Watts)(oC)(oC)(oC)(Volts)(psig)(Volts)(psig)(ms)(ms)(rpm)(cfs)(kg/m3)(g/s)

9/3/03na8.07.963.224.3026.20na0.6900.4050.7000.4500700285710.0681.2242.357

9/3/03na13.011.2145.625.1026.80na0.8601.1700.8701.2150414483090.1061.2823.849

9/3/03na16.013.3212.826.2027.30na1.0001.8001.0101.8450335.2596660.0841.3283.159

9/3/03na20.016.9338.028.1027.70na1.2102.7451.2102.7450276724640.0861.3923.389

9/3/03na24.022.5540.030.2031.70na1.3703.4651.3703.4650242826450.0971.4393.952

9/3/03na28.031.0868.0na37.00na1.4303.7351.4403.7800230.886655nana

Design Point Data

Pressure (psig)Speed

10.29150000

Testing of the single stage centrifugal compressor Required speed 150,000 rpm. Achieved Speed 97,000 rpm

Available Drivers

Coupling IssueFlexible Couplers operating 150K rpm not easily available in the market. A Flexible Coupler to be CUSTOM designed.

Design of Flexible Coupler involves

1) Misalignments (angular and parallel) due to oscillating stresses 2) System natural frequency Compressor and Motor3) Pulsating torque values need to be quantified for max torque and number of pulses per revolution.4) System excitation as well as Internal Flexure response must be analyzed.

Bearing IssueBearing:The misalignment and failure of the coupler leads to the failure of presently used ceramic ball bearings.Laser alignment of the system may reduce this problem considerably.Gas foil bearings are being designed to replace conventional bearings at a later stage.

CFD-Simulation

Sliding Mesh Model (SMM)GeometryCompressor PartsPro/E Drawing of the Compressor

Sliding Mesh Model (SMM)Geometry (continued)Pro/E drawing of Simulation Geometry

1.7M cells, 6 hours/time step on 1 sun Sparc station (30 time steps = 1 blade passing)

Sliding Mesh Model (SMM)(90,000rpm)The geometry was simulated under the condition that impeller rotating at 90,000rpm. The mass flow rate was found to be 3 g/s at Pout= 1.3 bar. This value agrees well to the experimental measurement.

Sliding Mesh Model (SMM)(150,000 rpm)A strong reversed flow and separation occur inside diffuser. Losses at the diffuser inlet is caused by high impeller outlet flow angle and swirl at the bend.

Geometry

Summary of CFD workIt is necessary to redesign the diffuser.We need deswirler vanes to reduce the swirl flow losses and correct the flow inlet angle at the diffuser inlet.Geometry should be simplified without affecting performance so that CFD runs can be faster and the design cycle can be shortened.

Future work of CFDModify diffuser to have 15 or 20 vanes.Simulate the compressor with cyclic boundary condition in order to shorten the computation timeCalculate correct flow/vane angles for the new designSimulate the redesigned compressor

Since the common factor between rows is 5, for the case with 20 diffuser vanes, only 2 IGVs, 1 impeller blade, and 2 diffuser vanes are needed in the computational domain. Comparing to the previous SMM simulation, the current implementation of cyclic boundary condition has reduced the calculation time from 6 hr per time step to 1 hr per time step (for 15 diffuser vanes), and further to half an hour per time step (for 20 diffuser vanes).Design with 15 diffuser vanes IGV (4), Impeller (2), Diffuser (3)

Bearing Design

To acquire a commercially available gas foil bearing suitable for the intended application of testing the motor and study its design.Gas Foil Bearingcourse of actionTo continue the design of gas foil bearings with the acquired knowledge base.

Design of Permanent magnet synchronous motorand control electronics

Proposed Motor Test Setup

Sectional View

PropertiesShaft :: Material : Titanium ( 6Al 4V) Yield Strength (77 K) : 1.4e+8 N/m2 Density : 4600 kg/m3

Magnet :: Samarium Cobalt (SmCo) (2-17) Compressive Strength : 833e+6 N/m2 Density : 8500 kg/m3

AnalysisMax stress due to centrifugal force is 419 MPaShaft Tolerance 5 0.01 0 mmMagnet Tolerance 5 0 +0.01 mm

The Titanium Shaft has CTE = 8.8 to 9e-6 /C The Magnet(SmCo) has CTE = 8.0 to 11e-6 /C

Heat the shaft to 248C and also cool the magnet to 196C and assemble it at room temperature.Max Thermal Stress developed during this process is 700 MPa. Resultant Thermal Stress Induced in the body while cooling it down to 77K is 914 MPa.As the Thermal Stress is developed due to Compression and Centrifugal Stress due to expansion , so while operating at 77K Resultant Stress < 1400 MPa (Yield Strength of Ti) Assembling Issues of Shaft and Magnet

Rotordynamic Analysis Results* for a Solid ShaftGas Bearing Stiffness : 50,000 lb/in with 2 mm wall thickness 1st Bending Critical Speed : 150,708 rpm

Gas Bearing Stiffness : 50,000 lb/in with 3 mm wall thickness 1st Bending Critical Speed : 152,410 rpm* Courtesy : Dr. Nagaraj Arakere (UFL)

Rotordynamic Analysis Results* for a Hollow Shaft* Courtesy : Dr. Nagaraj Arakere (UFL)Uniform wall thickness : 2 mm

Gas Bearing Stiffness : 10,000 lb/in 1st Bending Critical Speed : 170,097 rpm

Gas Bearing Stiffness : 50,000 lb/in 1st Bending Critical Speed : 227,790 rpm

Gas Bearing Stiffness : 10,000 lb/in with a flexible coupling 1st Bending Critical Speed : 350,149 rpm

Gas Bearing Stiffness : 50,000 lb/in with a flexible coupling 1st Bending Critical Speed : > 350,149 rpm

ManufacturingThe rotor is being machined by Wire EDM at present.The rotor shaft is 106.68 mm long, 16 mm in diameter.

Specifications

PMSM Cross SectionPermanent magnet: SmCo (Samarium Cobalt)Winding structure:6 turns/phase/poleGap length: 1.0 mmShaft thickness: 1.5 mmStator length: 21 mmPitch: 1 to 15

Permanent MagnetMagnet material: EEC 2:17-27 MGOe (SmCo).Magnetized thru the 13 mm dimensionPM StructureCross Section

Motor Stator0.005 silicon steel laminationID=0.970 (24.6 mm)OD= 1.380 (35.05 mm)Thickness: 21+/- 0.13 mmTotal 165 laminations per stack

WindingLitz-wire is used 3 x 25 strands @ AWG 36Diameter of AWG 36: 0.125 mmWire insulation: Heavy 200C Polyesterimide overcoated with polyamideimide to MW 351x half-lap 0.025 mm sofimide (like kapton) wrapOverall diameter: 1.60+/- 0.15 mmThis litz-wire can work at 77K.

Eddy Current of Solid WireEddy current is very large when using solid wire, so multi-strands Litz-wire is used to reduce eddy current loss.

Loss of 1/36 winding (Litz-wire)Pave=0.36 WLitz-wire: 75 strands @ AWG 36Total copper AC loss = 36 x 0.36= 13.0 W

Back EMF and Current @ 77KSimulated Torque=0.0975 N. mVery low harmonics in the back EMF waveforms.

Loss EstimationMotor Efficiency:Control Efficiency: Total Efficiency:(@ 77 K)

UnitR. T77 KCopper Loss DCW64.97.6Copper Loss ACW1.613.0Stator Iron LossW4.210.4Rotor LossW01.0 Windage & gas bearing LossW18.4 Filter LossW11 Total LossW101.161.4

Current ProgressWe have ordered the designed permanent magnets and it will be shipped in 4 weeks.We have ordered the designed Litz-wire which can work at 77 K. The Litz-wire will also be shipped in 4 weeks.We are currently preparing the purchase order for the motor stators.

The Control Scheme

Requirements of key componentsMOSFETStand up to 28 V voltage and 91 A current.Provide 2100 W output power.Low on-resistance.High switching frequency.Driver Chip Provide enough drive current to new higher power MOSFETs to correctly turn on and off.

Accomplishments till date Optimal thermodynamic, electrical and mechanical design of a 50 W cryocooler for pre-chilling, densification and ZBO of liquid hydrogen,

Complete validation of the single-stage compressor,

Validation of the design of motor and control system,

Design and fabrication of a compact recuperative heat exchanger for heat regeneration (done as a part of another project being funded by NASA KSC intended for a similar application).