农业工程学报
農業工程學報
농업공정학보
2015年
12期
92-98
,共7页
柴博森%王玉建%刘春宝%马文星%王文博
柴博森%王玉建%劉春寶%馬文星%王文博
시박삼%왕옥건%류춘보%마문성%왕문박
可视化%计算机仿真%涡流%液力变矩器%粒子图像测速%互相关%流速场%涡量场
可視化%計算機倣真%渦流%液力變矩器%粒子圖像測速%互相關%流速場%渦量場
가시화%계산궤방진%와류%액력변구기%입자도상측속%호상관%류속장%와량장
visualization%computer simulation%vortex flow%hydrodynamic torque converter%particle image velocimetry%cross-correlation%flow velocity field%vorticity field
液力变矩器是自动变速器的主要部件，其在乘用车、载重汽车、公共汽车和机车上的应用广泛。液力变矩器内部流动特性影响其外部性能，为了深入研究其内部流动特性，基于粒子图像测速（particle image velocimetry，PIV）技术对液力变矩器涡轮内流场进行试验研究。采用帧频为1000帧/s的CCD高速相机，在不同工况下（输入与输出的转速比分别取0、0.3、0.5、0.7）采集不同粒子直径、不同粒子浓度下的流动图像，经过图像预处理，对连续两帧图像进行互相关计算，获得涡轮径向切面的速度场和涡量场。通过对流场分布结构和流动区域上复杂流动现象的对比分析，发现投入流场中粒子浓度越高（1500 mL蒸馏水中投入2.4 g粒子）、粒子直径越小（10μm）时，识别并提取流动区域上的流动参数越丰富，流速场和涡量场信息越可靠。液力变矩器内部高梯度流场分布结构和非均匀流速场分布导致出现多尺度涡旋和反向流等复杂流动现象，造成液力变矩器内部流动能量损耗，随转速比提高，涡轮流场结构趋于规律，能耗逐渐降低。该文试验测量与分析结果对于液力变矩器结构优化和性能提升提供了参考。
液力變矩器是自動變速器的主要部件，其在乘用車、載重汽車、公共汽車和機車上的應用廣汎。液力變矩器內部流動特性影響其外部性能，為瞭深入研究其內部流動特性，基于粒子圖像測速（particle image velocimetry，PIV）技術對液力變矩器渦輪內流場進行試驗研究。採用幀頻為1000幀/s的CCD高速相機，在不同工況下（輸入與輸齣的轉速比分彆取0、0.3、0.5、0.7）採集不同粒子直徑、不同粒子濃度下的流動圖像，經過圖像預處理，對連續兩幀圖像進行互相關計算，穫得渦輪徑嚮切麵的速度場和渦量場。通過對流場分佈結構和流動區域上複雜流動現象的對比分析，髮現投入流場中粒子濃度越高（1500 mL蒸餾水中投入2.4 g粒子）、粒子直徑越小（10μm）時，識彆併提取流動區域上的流動參數越豐富，流速場和渦量場信息越可靠。液力變矩器內部高梯度流場分佈結構和非均勻流速場分佈導緻齣現多呎度渦鏇和反嚮流等複雜流動現象，造成液力變矩器內部流動能量損耗，隨轉速比提高，渦輪流場結構趨于規律，能耗逐漸降低。該文試驗測量與分析結果對于液力變矩器結構優化和性能提升提供瞭參攷。
액력변구기시자동변속기적주요부건，기재승용차、재중기차、공공기차화궤차상적응용엄범。액력변구기내부류동특성영향기외부성능，위료심입연구기내부류동특성，기우입자도상측속（particle image velocimetry，PIV）기술대액력변구기와륜내류장진행시험연구。채용정빈위1000정/s적CCD고속상궤，재불동공황하（수입여수출적전속비분별취0、0.3、0.5、0.7）채집불동입자직경、불동입자농도하적류동도상，경과도상예처리，대련속량정도상진행호상관계산，획득와륜경향절면적속도장화와량장。통과대류장분포결구화류동구역상복잡류동현상적대비분석，발현투입류장중입자농도월고（1500 mL증류수중투입2.4 g입자）、입자직경월소（10μm）시，식별병제취류동구역상적류동삼수월봉부，류속장화와량장신식월가고。액력변구기내부고제도류장분포결구화비균균류속장분포도치출현다척도와선화반향류등복잡류동현상，조성액력변구기내부류동능량손모，수전속비제고，와륜류장결구추우규률，능모축점강저。해문시험측량여분석결과대우액력변구기결구우화화성능제승제공료삼고。
The hydrodynamic torque converter is a major component of an automatic transmission. It transfers power from the engine to the transmission gearing system. The hydrodynamic torque converter has been applied in numerous automatic transmissions such as passenger cars, trucks, buses and trains. The external performance of hydrodynamic torque converter is affected by its internal flow characteristics. In order to study the internal flow characteristics of hydrodynamic torque converter, the internal flow field of hydrodynamic torque converter was tested based on particle image velocimetry (PIV) technology. As a powerful optical technique, instantaneous measurement of flow velocity at several positions in a plane can be tested by PIV. Instead of measuring at only one point in the flow field, such as laser doppler velocimetry and hot-wire anemometer, PIV has the ability to capture the spatial velocity distribution for a whole field simultaneously with high resolution. The technique is non-intrusive and no probe disturbs the flow. These features have made PIV a very useful technique in the characterization of unsteady and turbulent flow fields. PIV measurement can be performed in combination with other optical measurement methods to increase the understanding of complex phenomena. In order to capture high-quality flow images, hydrodynamic torque converter of transparent type was manufactured in imitation of the actual hydrodynamic torque converter, and plexiglass was chosen as the manufacturing material. In order to improve the transparency of experimental prototype, surface polishing was carried out several times. Aluminium powder was chosen as tracer particle, and distilled water was chosen as flowing medium. High speed camera was applied to capture flow images with different particle diameters and different particle concentrations under different working conditions. The shooting speed of charge-coupled device (CCD) was 1 000 frames per second. The velocity field and vorticity field of radial section in turbine were acquired through images preprocessing and cross-correlation calculation of 2 successive frames. A contrastive analysis of flow field distribution and complex flow phenomenon in flow area was done. It was found that flow parameters recognized and extracted in flow area were much richer when the concentration of particles was higher (2.4 g particles input to 1 500 mL distilled water) and the diameter of particles was smaller (10μm). At this time, the information of velocity field and vorticity field was more reliable. Complex flow phenomena, such as multi-scale vortex and reverse flow, were caused because of distribution structure of high-gradient flow field and inhomogeneous distribution of velocity field. And also, the energy loss of internal flow in hydrodynamic torque converter was caused. As the speed ratio increased, the structure of internal flow field became more disciplinary and the energy loss became lower. It has important engineering significance for structure optimization and performance improvement of hydrodynamic torque converter through the analysis of experimental measurement results.
