基于黏性比例因子的锥形流量计最优锥角选择

发布时间：2018-12-14 04:06

【摘要】：锥形流量计的锥角参数是影响锥形流量计性能的重要参数,锥体前锥角和后锥角均有较大的取值范围,这造成供选择的锥角组合无限多。通过实验和传统的CFD仿真优化锥形流量计锥角工作量大,效率低。研究证明了锥角的变化引起的下游取压位置处的压力波动会导致锥形流量计流出系数的改变。根据流体力学本构方程理论定义了评价黏性应力对压力波动影响的黏性应力比例因子k1和k2,并得到结论:任一锥角组合锥形流量计下游取压位置处黏性比例因子k1和k2越大,锥形流量计的压力信号受到的干扰越大,对应的流出系数重复性和线性度误差越差,在低入口雷诺数状态下这种干扰尤为明显。基于黏性比例因子的具有不同锥角组合锥形流量计的性能预测结论是:β值在0.45~0.75的锥形流量计,前锥角为27.5°±2.5°,后锥角为65°±5°时锥形流量计的流出系数重复性和线性度误差好于其他的锥角组合。实验测试DN100口径,β值分别为0.45,0.5和0.65的9个不同锥角组合的锥形流量计,实验结论证明了基于黏性应力比例因子的锥形流量计锥角组合预测的准确性。
[Abstract]:The cone angle parameter of the cone Flowmeter is an important parameter that affects the performance of the cone Flowmeter. Both the front cone angle and the posterior cone angle of the cone have a large range of values, which results in the infinite number of conical angle combinations available for selection. The conical angle of conical Flowmeter is optimized by experiment and traditional CFD simulation. It is proved that the pressure fluctuation at the downstream pressure position caused by the change of cone angle will result in the change of the outflow coefficient of the cone Flowmeter. According to the constitutive equation theory of fluid mechanics, the viscosity stress proportional factors k 1 and k 2 are defined to evaluate the influence of viscosity stress on pressure fluctuation. The results show that the greater the viscosity ratio factors k 1 and k 2 are at the lower pressure position of any cone angle combination cone Flowmeter. The greater the interference of the pressure signal of the cone Flowmeter, the worse the repeatability and linearity error of the corresponding outflow coefficient, especially under the condition of low inlet Reynolds number. The prediction results of the conical Flowmeter with different conical angles based on viscosity ratio factor are as follows: the conical Flowmeter with 尾 value of 0.450.75, the anterior cone angle of 27.5 掳卤2.5 掳, and the conical Flowmeter with different conical angles. When the posterior cone angle is 65 掳卤5 掳, the repeatability and linearity error of the conical Flowmeter are better than those of other conical angle combinations. Nine conical Flowmeters with DN100 caliber, 尾 = 0.45V 0.5 and 尾 = 0.65 are tested experimentally. The experimental results prove the accuracy of conical Flowmeter based on viscous stress ratio factor.
【作者单位】：天津大学电气与自动化工程学院;天津航海仪器研究所;
【基金】：国家自然科学基金(60974118)项目资助
【分类号】：TH814

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