An analysis method for the performance of compliant cylindrical intershaft gas film seal considering centrifugal expansion effect

A compliant cylindrical gas film seal has the potential to adapt to the complex operating conditions of a dual-rotor aeroengine, with radial runout and eccentricity, due to its special structural characteristics. To accurately investigate the seal performance of a compliant cylindrical gas film seal on dual-rotor shafts, an aeroelastic coupling method is proposed. This method analyzes the performance of a compliant cylindrical intershaft gas film seal by taking the centrifugal expansion effect into consideration. The seal performance under homodromy and counter-rotating conditions, with and without the centrifugal expansion effect, is calculated, and various performance parameters are compared and analyzed. Furthermore, the influence mechanism of the direction of rotation of the two rotors on seal performance is revealed. The results show that seal performance under homodromy condition is greater than under counter-rotating condition, and for an aeroengine under homodromy condition, it is advantageous to apply the compliant cylindrical intershaft gas film seal. The effect of centrifugal expansion (in large-diameter and high-speed rotors) and rotor eccentricity on the performance of a compliant cylindrical intershaft gas film seal, as well as the impact of inner and outer rotor speed on leakage rate, are analyzed and presented in this study. The proposed aeroelastic coupling method provides a promising guidance for the performance analysis of the compliant cylindrical gas film seal in single and dual- rotor systems.

Integrated Magnetics, Insulation and Cooling Architecture for Slotless Electric Machines

This paper proposes an integrated magnetics, insulation, and cooling architecture to improve the thermal performance of a high frequency permanent magnet (PM) motor. The proposed architecture can be used for any motor topology to improve its thermal and insulation performance. The proposed stator yoke design interleaves copper sheets between yoke core lamination to achieve better thermal conduction from winding to heat sink. A ceramic winding holder is integrated into the armature to introduce a parallel thermal conduction path from windings to the iron yoke and to provide additional insulation. The architecture is applied to a 300 kW slotless PM synchronous motor consisting of an outer rotor Halbach PM array, slotless stator, and heatsink. 3D electromagnetic finite element methods (FEM), 2D heat transfer FEM, and an analytical thermal circuit are used to analyze the architectures impact on torque production, eddy currents, and thermal performance when compared to the baseline motor. Finally, a pole-pair prototype was built as a proof-of-concept and to verify the performance benefits of the proposed architecture.

Integrated Magnetics, Insulation and Cooling Architecture for Slotless Electric Machines

This paper proposes an integrated magnetics, insulation, and cooling architecture to improve the thermal performance of a high frequency permanent magnet (PM) motor. The proposed architecture can be used for any motor topology to improve its thermal and insulation performance. The proposed stator yoke design interleaves copper sheets between yoke core lamination to achieve better thermal conduction from winding to heat sink. A ceramic winding holder is integrated into the armature to introduce a parallel thermal conduction path from windings to the iron yoke and to provide additional insulation. The architecture is applied to a 300 kW slotless PM synchronous motor consisting of an outer rotor Halbach PM array, slotless stator, and heatsink. 3D electromagnetic finite element methods (FEM), 2D heat transfer FEM, and an analytical thermal circuit are used to analyze the architectures impact on torque production, eddy currents, and thermal performance when compared to the baseline motor. Finally, a pole-pair prototype was built as a proof-of-concept and to verify the performance benefits of the proposed architecture.

MODIFIKASI MOTOR BRUSHLESS DC MENJADI GENERATOR SINKRON MAGNET PERMANEN FLUKS RADIAL PUTARAN RENDAH

Penelitian pembangkit listrik terus berkembang seiring meningkatnya kebutuhan energi listrik. Pemanfaatan sumber energi terbarukan seperti tenaga angin, tenaga air, tenaga gelombang laut serta tenaga arus laut memerlukan generator listrik putaran rendah tanpa eksitasi tambahan untuk dapat menghasilkan energi listrik. Generator sinkron magnet permanen (PMSG) merupakan generator yang medan eksitasinya dihasilkan oleh medan magnet permanen. Generator ini memiliki keunggulan dapat beroperasi pada putaran rendah serta tinggi memiliki tingkatan efisiensi yang lebih baik dibanding dengan generator induksi. Penggunaan PMSG bisa didapat dengan memanfaatkan motor BLDC mesin cuci bekas tipe satu tabung. Spesifikasi motor BLDC tipe outer rotor memiliki kumparan stator berbentuk roda gigi berinti besi berjumlah 36 coil dengan wiring 1 x 12 coil 3 fasa, terdiri 90 lilitan tiap coil dengan diameter penampang kawat 0,8 mm, berbahan alumunium dengan jenis belitan concentrated. Rotor memiliki 12 batang magnet permanen berbahan Barium ferrite (BaO 6Fe2O3). Secara konstruksi motor BLDC dan PMSG memiliki sebuah kemiripan dimana pada bagian rotornya terdapat magnet permanen, sehingga motor BLDC dapat dipertimbangkan untuk diaplikasikan sebagai generator. Hasil pengujian generator dari BLDC dapat membangkitkan daya listrik sebesar 855 VA pada kecepatan putar 1300 RPM, tegangan kerja generator sebesar 200 VAC fasa-netral, 350 VAC fasa-fasa dengan efisiensi sebesar 68,2 % .