Finite volume analysis of airflow field in the dual-feed and conventional rotor spinning unit Presenter: Nicholus Tayari Akankwasa Ph.D. Fellow, College of Textiles, Donghua University  ORCID: http://orcid.org/0000-0001-8571-4261

Introduction Conventional Rotor spinning The dual-feed concept Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Introduction Conventional Rotor spinning The dual-feed concept Over 4 decades existence High production Cost effective low strength yarns compared other spinning methods Costly blending One decade invention Modified notion Improved yarn properties Effective blending Not commercialized 2

Related Works The dual-feed unit research 3 Conventional unit Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Related Works The dual-feed unit research Conventional unit M. Hajilari et al, 2007 A.Peyvari et al et al, 2014 Trash removal was achieved Fibers opened by a single opening roller Prototype achieved spinning synthetic fibers Challenge with trash removal 2/7 3

Proposed Approach 4 Rotor Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Proposed Approach Rotor D= 40mm h= 15mm d1 = 4mm d= 1mm L = 2mm β = 25.3 ͦ Φ = 2mm θ = 66 ͦ 4

Our Goal Evaluate 3-D airflow in two models Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Our Goal Evaluate 3-D airflow in two models Develop a computational model Analyze the flow domain based on FVM Study the interior flow characteristics Evaluate the yarn properties 5 5

Experimental Details Model construction Grid independency test Meshing Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Experimental Details Model construction Grid independency test Meshing Solidworks Ansys Fluent Turbulent k-ɛ model Size 1,030,182 tetrahedron cells SIMPLE- discretization Simulation runs and CFD visualization Analyze CFD results Yarn properties comparison 6

Experimental Details Mesh and boundary conditions Geometrical model 7 Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Experimental Details Mesh and boundary conditions Geometrical model 7

Experimental Details Parameters specification 8 Parameter Value Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Experimental Details Parameters specification Parameter Value Velocity inlet, m/s 20 Pressure inlet, Pa -7000 Pressure outlet, Pa 1.01 x 105 Rotor speed, rpm 100,000 Iterations 6000 8

Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Experimental Details Grid independence test velocity variation at x-z plane at y=2mm along x-axis: (a, b) Conventional rotor spinning unit; (c,d) novel dual-feed rotor spinning unit. 9

Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Results and Analysis Flow Visualization: Velocity magnitude Iso-surfaces Iso-surfaces of velocity magnitude (a, c) a dual-feed model, (b, d) conventional model(FVM) Extraction of the velocity profiles in the two models was achieved in Tecplot CFD 10

Results and Analysis Flow Visualization: Negative pressure comparison Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Results and Analysis Flow Visualization: Negative pressure comparison At z=0.228mm (a) Conventional rotor spinning unit, (b) dual-feed rotor spinning unit; z=0.468mm (c) conventional rotor spinning unit, (d) dual-feed rotor spinning unit. 11

Results and Analysis Vortices visualization along rotor vertical axis Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Results and Analysis Vortices visualization along rotor vertical axis Vortices visualization along rotor vertical axis(y=2-6, 8mm): 12

Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Results and Analysis Comparison of yarn properties 55/45 Polyester cotton Yarn sample Dual-feed model Conventional model Tenacity (cN/tex) 14.321 12.633 Elongation (%) 11.026 10.162 Yarn evenness and imperfections /km CVm (%) 15.4 17.03 Thin (-35%) 12.4 16.2 Thick (+35%) 9.33 9.96 Hairiness 3 mm 4.2 4.3 13

Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Conclusions The second channel improves the way fibers are aligned in the yarn structure leading to improved yarn properties. Computational model adopted clearly represents the flow behavior in the rotor interior. Even distribution of velocity and pressure in a dual-feed model 14

Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Conclusions Stream traces and vortices attain an orderly path in the new model Dual-feed spun yarns have better tenacity, elongation at break, hairiness, and less thick and thin places. 15

References [1] Kong LX and Platfoot RA. 2007 Text. Res. J. 67 269 Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions References [1] Kong LX and Platfoot RA. 2007 Text. Res. J. 67 269 [2] Akankwasa NT, Lin H, Zhang Y and Wang J. 2016 Text. Res. J. [3] Lin HT, Zeng YC and Wang J. 2016 Text. Res. J. 86 115 [4] Hajilari, M., Eskandarnejad S. , Behzadan H. , and M. B. Moghadam. 2007. Fibers and Polymers 8(5):543–49. [5] Peyravi, A., Eskandarnejad S. , and Mohammad B. 2014. The J. of Tex. Instit.105(4):377–82. 16

Introduction Related Works Proposed Approach Experimental Details Results and Analysis Conclusions Our related works Akankwasa NT, Lin H, Zhang Y, et al. Numerical simulation of three-dimensional airflow in a novel dual-feed rotor spinning box. Text Res J 2016 Akankwasa Nicholus Tayari, Lin Huiting , Wang Jun, Evaluation of the dual-feed rotor spinning unit based on airflow dynamics and blended yarn properties Journal of the Textile Institute, In press p 1-12, March 25, 2017 Huiting Lin, Josep M Bergadà, Yongchun Zeng, Akankwasa Nicholus Tayari, Yuze Zhang, Jun Wang,2017 Rotor spinning transfer channel design optimization via Computational Fluid Dynamics Textile Research Journal 2017 Nicholus Tayari Akankwasa, Lin H, Wang J. Evaluation of drag and lift in the internal flow field of a dual rotor spinning unit via CFD. In: 2nd International Conference on Mechanical, Manufacturing, Modeling and Mechatronics, University of Gent. Matec Web of Conferences, 2017, p. 1-6 Lin Huiting, Akankwasa Nicholus Tayari and Wang Jun 2017 Simulating fiber motion in the airflow in a rotor spinning unit MATEC Web Conference; 2017 volume: 104, DOI: 10.1051/matecconf/201710402004 More details:  ORCID: http://orcid.org/0000-0001-8571-4261  17

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