BARC/2010/E/002 BARC/2010/E/002 CFD SIMULATION OF FLOW THROUGH SINGLE AND MULTI VANE SPIRAL PUMP FOR LOW PRESSURE APPLICATION USING MOVING NODE UNSTEADY COMPUTATION by I. Banerjee, A.K. Mahendra, B.G. Chandresh, M.R. Srikanthan and T.K. Bera Chemical Technology Group 2010 BARC/2010/E/002 GOVERNMENT OF INDIA ATOMIC ENERGY COMMISSION BARC/2010/E/002 CFD SIMULATION OF FLOW THROUGH SINGLE AND MULTI VANE SPIRAL PUMP FOR LOW PRESSURE APPLICATION USING MOVING NODE UNSTEADY COMPUTATION by I. Banerjee, A.K. Mahendra, B.G. Chandresh, M.R. Srikanthan and T.K. Bera Chemical Technology Group BHABHA ATOMIC RESEARCH CENTRE MUMBAI, INDIA 2010 BARC/2010/E/002 BIBLIOGRAPHIC DESCRIPTION SHEET FOR TECHNICAL REPORT (as per IS : 9400 - 1980) 01 Security classification : Unclassified 02 Distribution : External 03 Report status : New 04 Series : BARC External 05 Report type : Technical Report 06 Report No. : BARC/2010/E/002 07 Part No. or Volume No. : 08 Contract No. : 10 Title and subtitle : CFD simulation of flow through single and multi vane spiral pump for low pressure application using moving node unsteady computation 11 Collation : 47 p., 5 figs., 2 tabs., 2 ills. 13 Project No. : 20 Personal author(s) : I. Banerjee; A.K. Mahendra; B.G. Chandresh; M.R. Srikanthan; T.K. Bera 21 Affiliation of author(s) : Chemical Technology Group, Bhabha Atomic Research Centre, Mumbai 22 Corporate author(s) : Bhabha Atomic Research Centre, Mumbai - 400 085 23 Originating unit : Chemical Technology Group, BARC, Mumbai 24 Sponsor(s) Name : Department of Atomic Energy Type : Government Contd... BARC/2010/E/002 30 Date of submission : December 2009 31 Publication/Issue date : January 2010 40 Publisher/Distributor : Head, Scientific Information Resource Division, Bhabha Atomic Research Centre, Mumbai 42 Form of distribution : Hard copy 50 Language of text : English 51 Language of summary : English, Hindi 52 No. of references : 27 refs. 53 Gives data on : 60 Abstract : A spiral pump uses two interleaved spirals (it can be involutes of a circle, involutes of a square, hybrid wraps, Archimedean spiral, logarithmic spirals and so on). Interleaved spiral orbits eccentrically without rotation around a fixed scroll, thereby trapping and compressing pockets of fluids between the spirals. Another method of providing the compression motion is by virtue of co-rotating the spirals synchronously with an offset in centers of rotation thereby providing relative motion similar to orbiting. Recently spiral pumps for low-pressure application have become popular. Since spiral pumps contain gas volumes, whose shapes and size change continuously, the flow fields inside the pumps is time dependent. The unsteadiness controls the mechanisms responsible for the behavior of the spiral pump components. To improve the spiral pump design for better performance as per our process requirement and reliability, information is required to understand the detailed physics of the unsteady flows inside the spiral pumps. The unsteady flows in a pump are studied numerically. The system simulated includes one side gap between fixed and moving spirals as the other side lies just in the reverse symmetry of the one side. Heavy molecular weight, condensable gas is used as the moving fluid. The mesh free Least Square Kinetic Upwind Method (LSKUM) for moving node is applied for numerical analysis of wobbling spiral. Nodes and boundaries change their positions, for every real time step hence at every iteration nodes take new coordinates. Our work consists of identifying various spiral dimensions and geometry, geometric modeling of suction process, identifying the eccentric orbiting motion of the moving spiral, formation of variable velocity moving nodes. Flow analysis of the spiral pump is done with a view to design and develop new pump as per our requirement. Experimental data from an existing spiral pump is used to carryout validation of the code. 70 Keywords/Descriptors : UNSTEADY FLOW; REAL TIME SYSTEMS; COMPUTERIZED SIMULATION; FLUID MECHANICS; BOLTZMANN EQUATION; VANES 71 INIS Subject Category : S42 99 Supplementary elements : ÃÖÖ¸üÖÓ¿Ö ‹ú ÃÖÙ¯Ö»Ö ¯ÖÓ¯Ö, ¤üÖê †ÓŸÖ¸üÖ¯Ö×¡ÖŸÖ ÃÖÙ¯Ö»ÖÖë úÖ ¯ÖÏμÖÖêÖ ú¸üŸÖÖ Æîü (μÖÆü ‹ú ¾Öé¢Ö úÖ ¯ÖÏןÖêú−¦ü•Ö, ‹ú ¾ÖÖÔ úÖ ¯ÖÏןÖêú−¦ü•Ö, ÃÖÓú¸ü †Ö¾Ö¸üÖ, †ÖÙú´Öß›üßμÖ ÃÖÙ¯Ö»Ö, »ÖÖòÖê׸ü£´ÖßμÖ ÃÖÙ¯Ö»Ö ‡ŸμÖÖפü ÆüÖê ÃÖúŸÖÖ Æîü )… †ÓŸÖ¸üÖ¯Ö×¡ÖŸÖ ÃÖÙ¯Ö»Ö, ‹ú Ûãָü ÃÎúÖò»Ö êú “ÖÖ¸üÖë †Öê¸ü ‘ÖæÖÔ−Ö êú ײÖ−ÖÖ ˆŸêúÛ−¦üŸÖ ÆüÖêú¸ü ¯Ö׸üÎú´ÖÖ ú¸üŸÖÖ Æîü, וÖÃÖÃÖê ¾ÖÆü ÃÖÙ¯Ö»ÖÖë êú ²Öß“Ö ŸÖ¸ü»ÖÖë êú ¯ÖÖòêú™üÖë úÖê ±ÑúÃÖÖŸÖÖ Æîü ŸÖ£ÖÖ ÃÖÓ¯Öß×›ÍüŸÖ ú¸üŸÖÖ Æîü … ÃÖÓ¯Öß›Í−Ö Ö×ŸÖ ¯ÖϤüÖ−Ö ú¸ü−Öê úß †−μÖ ×¾Ö׬Ö, ‘ÖæÖÔ−Ö êú ëú¦üÖë ´Öë ‹ú †Öò±úÃÖê™ü êú ÃÖÖ£Ö ÃÖÙ¯Ö»ÖÖë úÖê ÃÖ´Ö Îú×´Öú ÃÖÆü‘ÖæÙÖŸÖ ú¸ü−ÖÖ Æîü וÖÃÖÃÖê ¯Ö׸üÎú´ÖÖ êú ÃÖ´ÖÖ−Ö ÃÖÖ¯Öê×Öú Ö×ŸÖ ¯ÖϤüÖ−Ö úß •ÖÖŸÖß Æîü … ÆüÖ»Ö ´Öë ×−Ö´−Ö ¤üÖ²Ö †−Öã¯ÖÏμÖÖêÖ ÆêüŸÖã ÃÖÙ¯Ö»Ö ¯ÖÓ¯Ö ¯ÖÏ“Ö×»ÖŸÖ ÆüÖê Ö‹ Æïü … “ÖæÓ×ú ÃÖÙ¯Ö»Ö ¯ÖÓ¯ÖÖë ´Öë ÖîÃÖßμÖ †ÖμÖŸÖ−Ö ÆÖêüŸÖÖ Æîü, †ŸÖ: ˆ−Öúß †Öéú×ŸÖ ‹¾ÖÓ †ÖúÖ¸ü ×−Ö¸ÓüŸÖ¸ü ²Ö¤ü»ÖŸÖê ¸üÆüŸÖê Æïü, ¯ÖÓ¯ÖÖë êú ³Öߟָü ¯ÖϾÖÖÆü Öê¡Ö úÖ»ÖÖ×ÁÖŸÖ Æïü … †ÛãָüŸÖÖ, úÖμÖÔ×¾Ö×¬Ö úÖê ×−ÖμÖÓ×¡ÖŸÖ ú¸üŸÖÖ Æîü •ÖÖê ÃÖÙ¯Ö»Ö ¯ÖÓ¯Ö ‘Ö™üúÖë êú ¾μÖ¾ÖÆüÖ¸ü ÆêüŸÖã וִ´Öê¤üÖ¸ü üÆîü… ÃÖÙ¯Ö»Ö ¯ÖÓ¯Ö êú ×›ü•ÖÖ‡−Ö êú Æü´ÖÖ¸ß ¯ÖÏÎú´Ö †¯ÖêÖÖ†Öë ŸÖ£ÖÖ ×¾Ö¿¾ÖÃÖ−ÖßμÖŸÖÖ úê †−ÖãÃÖÖ¸ü ²ÖêÆüŸÖ¸ü úÖμÖÔ ×−Ö¯ÖÖ¤ü−Ö êú ×»Ö‹ ÃÖÙ¯Ö»Ö ¯ÖÓ¯ÖÖë êú ³Öߟָü †Ûãָü ¯ÖϾÖÖÆü úß ×¾ÖßÖéŸÖ ³ÖÖîןÖúß úÖê ÃÖ´Ö—Ö−Öê ÆêüŸÖã •ÖÖ−ÖúÖ¸üß úß †Ö¾Ö¿μÖúŸÖÖ Æîü … ‹ú ¯ÖÓ¯Ö ´Öë †Ûãָü ¯ÖϾÖÖÆü úÖ †¬μÖμÖ−Ö ÃÖÓμÖÖŸ´Öú ºþ¯Ö ´Öë ×úμÖÖ •ÖÖŸÖÖ Æîü … †−ÖãúÖ׸üŸÖ ¯ÖÏÖÖ»Öß ´Öë †“Ö»Ö ŸÖ£ÖÖ ÖןִÖÖ−Ö ÃÖÙ¯Ö»ÖÖë êú ²Öß“Ö ‹ú ÃÖÖ‡Ô›ü Öî¯Ö ¿ÖÖ×´Ö»Ö Æîü “ÖæÓ×ú †−μÖ ÃÖÖ‡›ü, ‹ú ÃÖÖ‡›ü êú šüßú ×¾Ö¯Ö¸üßŸÖ ÃÖ´Ö×´Ö×ŸÖ ´Öë ÛÃ£ÖŸÖ Æîü … ³ÖÖ¸üß †Öã³ÖÖ¸ü, ÃÖÓ‘Ö−ÖßμÖ ÖîÃÖ úÖ ¯ÖÏμÖÖêÖ ÖןִÖÖ−Ö ŸÖ¸ü»Ö êú ºþ¯Ö ´Öë ×úμÖÖ •ÖÖŸÖÖ Æîü … ÖןִÖÖ−Ö −ÖÖê›ü êú ×»Ö‹ ×”û¦ü ¸ü×ÆüŸÖ »ÖßÙü ÃŒ¾ÖêμÖ¸ü úÖ‡−Öê×™üú †¯Ö¾ÖÖ‡Ó›ü ´Öê£Ö›ü (LSKUM) ›üÖ´ÖÖ ÃÖÙ¯Ö»Ö êú ÃÖÓμÖÖŸ´Öú ×¾Ö¿»ÖêÂÖÖ ÆêüŸÖã †−Öã¯ÖÏμÖÖêÖ ×úμÖÖ ÖμÖÖ Æîü … −ÖÖê›ËüÃÖ ‹¾ÖÓ ²ÖÖˆÓ›ü¸üß, ¯ÖÏŸμÖêú ¾ÖÖßÖ×¾Öú úÖ»Ö ˆ¯ÖÖμÖ ÆêüŸÖã †¯Ö−Öß ÛãÖןÖμÖÖÓ ²Ö¤ü»ÖŸÖê Æïü †ŸÖ: ¯ÖÏŸμÖêú ¯Öã−Ö¸üÖ¾Öé×¢Ö −ÖÖê›ü ¯Ö¸ü −Ö‹ ×−Ö¤íü¿ÖÖÓú »ÖêŸÖê Æïü … Æü´ÖÖ¸êü úÖμÖÔ ´Öë ×¾Ö×³Ö®Ö ÃÖÙ¯Ö»Ö »ÖÓ²ÖÖ‡Ô-“ÖÖî›ÍüÖ‡Ô ‹¾ÖÓ •μÖÖ×´Ö×ŸÖ úß ¯ÖÆü“ÖÖ−Ö, “ÖæÂÖÖ ¯ÖÏÎú´Ö úÖ •μÖÖ×´ÖŸÖßμÖ ¯ÖÏןֺþ¯ÖÖ, ÖןִÖÖ−Ö ÃÖÙ¯Ö»Ö êú ˆŸêú−¦ü úÖÖ Ö×ŸÖ úß ¯ÖÆü“ÖÖ−Ö, “Ö¸ü¾ÖêÖ ÖןִÖÖ−Ö −ÖÖê›üÖë úÖ ×−Ö´ÖÖÔÖ ×−Ö×ÆüŸÖ ÆîüÓ … ÃÖÙ¯Ö»Ö ¯ÖÓ¯Ö úÖ ¯ÖϾÖÖÆü ×¾Ö¿»ÖêÂÖÖ Æü´ÖÖ¸ß †¯ÖêÖÖ êú †−ÖãÃÖÖ¸ü −Ö‹ ¯ÖÓ¯Ö êú ×›ü•ÖÖ‡−Ö ‹¾ÖÓ ×¾ÖúÖÃÖ êú ˆ§êü¿μÖ ÃÖê ×úμÖÖ •ÖÖŸÖÖ Æîü … ‹ú ×¾Öª´ÖÖ−Ö ÃÖÙ¯Ö»Ö ¯ÖÓ¯Ö ÃÖê ¯ÖÏÖμÖÖê×Öú †ÖÓú›Íêü úÖ ¯ÖÏμÖÖêÖ úÖê›ü úÖ ´ÖÖ−μÖú¸üÖ ú¸ü−Öê ÆêüŸÖã ×úμÖÖ •ÖÖŸÖÖ Æîü … Abstract A Spiral pump uses two interleaved spirals (it can be involutes of a circle, involutes of a square, hybrid wraps, Archimedean spiral, logarithmic spirals and so on). Interleaved spiral orbits eccentrically without rotation around a fixed scroll, thereby trapping and compressing pockets of fluids between the spirals. Another method of providing the compression motion is by virtue of co-rotating the spirals synchronously with an offset in centers of rotation thereby providing relative motion similar to orbiting. Recently spiral pumps for low-pressure application have become popular. Since spiral pumps contain gas volumes, whose shapes and size change continuously, the flow fields inside the pumps is time dependent. The unsteadiness controls the mechanisms responsible for the behavior of the spiral pump components. To improve the spiral pump design for better performance as per our process requirement and reliability, information is required to understand the detailed physics of the unsteady flows inside the spiral pumps. The unsteady flows in a pump are studied numerically. The system simulated includes one side gap between fixed and moving spirals as the other side lies just in the reverse symmetry of the one side. Heavy molecular weight, condensable gas is used as the moving fluid. The mesh free Least Square Kinetic Upwind Method (LSKUM) for moving node is applied for numerical analysis of wobbling spiral. Nodes and boundaries change their positions, for every real time step hence at every iteration nodes take new coordinates. Our work consists of identifying various spiral dimensions and geometry, geometric modeling of suction process, identifying the eccentric orbiting motion of the moving spiral, formation of variable velocity moving nodes. Flow analysis of the spiral pump is done with a view to design and develop new pump as per our requirement. Experimental data from an existing spiral pump is used to carryout validation of the code. Acknowledgements The authors would like to acknowledge Fabrication & Maintenance Section of RMP, Mysore for performing critical indigenous assembly of spiral pump.