大梯度低速流场中五孔探针测量误差修正方法研究

Investigation on error correction method of five-holes probes used in flow field with large velocity gradient

  • 摘要: 为探究大梯度流场下五孔探针的失真特性,建立了用于修正速度梯度(ΔV/V)所引起的测量误差的数据处理方法。从五孔探针测量原理出发,研究了梯度流场下,气流角和梯度大小对于五孔探针测量误差的影响,提出了减小测量误差的修正方法;采用实验方法验证了该修正方法的准确性。研究结果表明,探针的速度测量误差远小于角度误差,在所研究的梯度范围内(ΔV/V = ± 0.3)通常可忽略;探针角度测量误差通常较为显著,其大小不仅受速度梯度的影响,还与气流的来流角度有关。实验结果证明了本文提出的基于梯度和气流角的修正方法能有效减小角度测量误差。

     

    Abstract: In order to explore the distortion characteristics of the five-holes probe under a large gradient flow field (ΔV/V), a data processing method for correcting the measurement error caused by the velocity gradient is established. An investigation based on the five-holes probe principle is employed to reveal the effect of the flow angle and velocity gradient on the measurement error. A correct method is proposed and verified by the experiment. The results show: the measurement error of the velocity value is far less than that of the flow angle and can be ignored in ordinary range (ΔV/V = ± 0.3 in this paper). The measurement error of the flow angle is usually notable. The error is affected by the velocity gradient and flow angle. The results of the experiment confirm that the correction method based on the velocity gradient and flow angle can reduce the angle error effectively.

     

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