实验流体力学
實驗流體力學
실험류체역학
JOURNAL OF EXPERIMENTS IN FLUID MECHANICS
2014年
6期
66-72
,共7页
2D-PIV%透视误差%误差分析%流向旋涡%离轴角%视场系数
2D-PIV%透視誤差%誤差分析%流嚮鏇渦%離軸角%視場繫數
2D-PIV%투시오차%오차분석%류향선와%리축각%시장계수
2D-PIV%perspective error%error analysis%streamwise vortex%off-axis angle%view coefficient
常规二维粒子图像测速技术(2D-PIV)作为重要的流场测试手段,被越来越多地应用到各种类型的流场测量中。然而采用该技术对垂直于流向的截面进行测量时会产生明显误差,该误差是由2D-PIV 原理中几何透视成像关系引起。本文分析了测量截面内有法向速度分量时透视误差产生原因及影响因素,建立了2D-PIV 测量平面内的误差模型。通过实验测试验证了误差模型的正确性,确定了影响测量误差的关键参数为测量平面的法向速度和视场的离轴角。计算结果显示,最大透视误差可达法向速度的9.3%。根据误差模型进行分析,透视误差对流向涡类流场测量的影响主要为3个方面:改变流场速度量值大小、改变旋涡形状、改变旋涡的位置。最后,提出了一些减小误差的措施,为2D-PIV应用于垂直流向截面的测量提供了改进方法。
常規二維粒子圖像測速技術(2D-PIV)作為重要的流場測試手段,被越來越多地應用到各種類型的流場測量中。然而採用該技術對垂直于流嚮的截麵進行測量時會產生明顯誤差,該誤差是由2D-PIV 原理中幾何透視成像關繫引起。本文分析瞭測量截麵內有法嚮速度分量時透視誤差產生原因及影響因素,建立瞭2D-PIV 測量平麵內的誤差模型。通過實驗測試驗證瞭誤差模型的正確性,確定瞭影響測量誤差的關鍵參數為測量平麵的法嚮速度和視場的離軸角。計算結果顯示,最大透視誤差可達法嚮速度的9.3%。根據誤差模型進行分析,透視誤差對流嚮渦類流場測量的影響主要為3箇方麵:改變流場速度量值大小、改變鏇渦形狀、改變鏇渦的位置。最後,提齣瞭一些減小誤差的措施,為2D-PIV應用于垂直流嚮截麵的測量提供瞭改進方法。
상규이유입자도상측속기술(2D-PIV)작위중요적류장측시수단,피월래월다지응용도각충류형적류장측량중。연이채용해기술대수직우류향적절면진행측량시회산생명현오차,해오차시유2D-PIV 원리중궤하투시성상관계인기。본문분석료측량절면내유법향속도분량시투시오차산생원인급영향인소,건립료2D-PIV 측량평면내적오차모형。통과실험측시험증료오차모형적정학성,학정료영향측량오차적관건삼수위측량평면적법향속도화시장적리축각。계산결과현시,최대투시오차가체법향속도적9.3%。근거오차모형진행분석,투시오차대류향와류류장측량적영향주요위3개방면:개변류장속도량치대소、개변선와형상、개변선와적위치。최후,제출료일사감소오차적조시,위2D-PIV응용우수직류향절면적측량제공료개진방법。
As an important means of field testing,conventional two dimensional Particle Im-age Velocimetry (2D-PIV)has been widely applied to various flow measurements.Measurement error arises when 2D-PIV is applied to measure the cross section perpendicular to the flow due to geometric perspective relations.The error factors are analyzed and a model of the error in the measurement plane is established.The correctness of the error model is verified by experimental tests .It is concluded that the normal speed and off-axis angle of view are the key influencing fac-tors.The calculation results show that the maximum perspective error can be up to 9 .3%of nor-mal speed.According to the analysis of error model,the effect of perspective error on measure-ment of streamwise vortex flow field mainly exhibits in three aspects:changing the velocity value of flow field,changing the shape of vortex,and changing the position of the vortex.Finally, some approaches to reduce the error are proposed,which can improve the measurement for the application of 2D-PIV in the cross section perpendicular to the flow.