Analysis of chamber effect on intermittent pulsation

Abstract

A numerical study was conducted to seek an optimized dimension of jet chamber in the pulsating impinging flow. The flow and heat transfer effect of the pulsation flow through a jet chamber was investigated. The numerical results indicate that heat transfer effective enhances near the stagnation region for the intermittent pulsed flow with jet chamber compared to that without jet chamber. Simulations of the flow through a jet chamber show that the heat transfer rate on the impingement surface is highly dependent on the velocity at the position which is really close to target surface. Examination of the velocity field suggests that the velocity exists a maximum value as the axis distance increases. In addition, the velocity at the jet hole is enlarged by the jet chamber due to the entrainment effect, and the velocity is amplified even greater as the size of the jet chamber becomes bigger. Nevertheless, the velocity declines quickly while the flow axis distance is more than a certain range, leading to poor heat transfer. Thus, intermittent pulsed flow with jet chamber is suggested as a method of improving heat transfer by employing larger dimensions of jet chamber for appropriate jet-to-surface spacing.

Keywords

pulsed impinging jet / intermittent pulsation / jet chamber / Nusselt number

References

[1] PolatS. Heat and mass transfer in impingement drying [J]. Drying Technology, 1993, 11(6): 1147-1176

[2] MartinH. Heat and mass transfer between impinging gas jets and solid surface [J]. Advanced Heat Transfer, 1977, 13: 1-60

[3] HofmannH M, MovileanuD L, KindM, MartinH. Influence of a pulsation on heat transfer and flow structure in submerged impinging jets [J]. International Journal of Heat and Mass Transfer, 2007, 50(17): 3638-3648

[4] HerwigH, MiddelbergG. The physics of unsteady jet impingement and its heat transfer performance [J]. Acta Mechanica, 2008, 201(1/2/3/4): 171

[5] MiddelbergG, HerwigH. Convective heat transfer under unsteady impinging jets: The effect of the shape of the unsteadiness [J]. Heat and Mass Transfer, 2009, 45(12): 1519-1532

[6] ZhouJ-w, WangY-g, MiddelbergG, HerwigH. Unsteady jet impingement heat transfer on smooth and non-smooth surfaces [J]. International Communications in Heat and Mass Transfer, 2009, 36(2): 103-110

[7] PakhomovM A, TerekhovV I. Effect of pulse frequency on heat transfer at the stagnation point of an impinging turbulent jet [J]. High Temperature, 2013, 51(2): 256-261

[8] MedinaH, BenardE, EarlyJ M. Reynolds number effects on fully developed pulsed jets impinging on flat surfaces [J]. AIAA Journal, 2013, 51(10): 2305-2318

[9] PersoonsT, BalgazinK, BrownK, MurrayD B. Scaling of convective heat transfer enhancement due to flow pulsation in an axisymmetric impinging jet [J]. Journal of Heat Transfer, 2013, 135(11): 803-816

[10] AstaritaT, CardoneG. Convective heat transfer on a rotating disk with a centred impinging round jet [J]. International Journal of Heat & Mass Transfer, 2008, 51(7/8): 1562-1572

[11] WangB-x, XieQ, WangZ-d, WangG-dong. Fluid flow characteristics of single inclined circular jet impingement for ultra-fast cooling [J]. Journal of Central South University, 2013, 20: 2960-2966

[12] LiewkongsatapornW, PattersonT, AhrensF. Pulsating jet impingement heat transfer enhancement [J]. Drying Technology, 2008, 26(4): 433-442

[13] JanetzkeT, NitscheW, TageJ. Experimental investigations of flow field and heat transfer characteristics due to periodically pulsating impinging air jets [J]. Heat and Mass Transfer, 2008, 45(2): 193-206

[14] JanetzkeT, NitscheW. Time resolved investigations on flow field and quasi wall shear stress of an impingement configuration with pulsating jets by means of high speed PIV and a surface hot wire array [J]. International Journal of Heat and Fluid Flow, 2009, 30(5): 877-885

[15] XuP, QiuS-x, YuM-z, QiaoX-w, MujumdarA S. A study on the heat and mass transfer properties of multiple pulsating impinging jets [J]. International Communications in Heat and Mass Transfer, 2012, 39(3): 378-382

[16] ShiJ-h, YuanG, JiangL-y, ZhaoK, WangG-dong. Numerical analysis of heat transfer intensity from twin slot vertical jet impingement on strip surface after hot rolling [J]. Journal of Central South University, 2015, 22: 2816-2824

[17] MohammadpourJ, Rajabi-ZargarabadiM, MujumdarA S, AhmadiH. Effect of intermittent and sinusoidal pulsed flows on impingement heat transfer from a concave surface [J]. International Journal of Thermal Sciences, 2014, 76: 118-127

[18] MohammadpourJ, ZolfagharianM M, MujumdarA S, ZargarabadiM R, MohammadA. Heat transfer under composite arrangement of pulsed and steady turbulent submerged multiple jets impinging on a flat surface [J]. International Journal of Thermal Sciences, 2014, 86: 139-147

[19] LiakosH H, KeramidaE P, FountiM A, MarkatosN C. Heat and mass transfer study of impinging turbulent premixed flames [J]. Heat Mass Transfer, 2002, 38(4/5): 425-432

[20] ZhangJ-z, XieH, YangC-feng. Numerical study of flow and heat transfer characteristics of impingement/effusion cooling [J]. Chinese Journal of Aeronautics, 2009, 22(4): 343-348

[21] ParhamK, EsmaeilzadehE, AtikolU, AldabbaghL B Y. A numerical study of turbulent opposed impinging jets issuing from triangular nozzles with different geometries [J]. Heat Mass Transfer, 2010, 47(4): 427-437

[22] SharifM A R, MotheK K. Parametric study of turbulent slot-jet impingement heat transfer form concave cylindrical surfaces [J]. International Journal of Thermal Science, 2009, 49(2): 428-442