基于响应曲面法的交错肋换热特性研究

Heat transfer characteristics of cross ribs based on response surface methodology

关键词:  燃气轮机  涡轮叶片  交错肋  响应曲面法  换热特性

Key words:  Gas turbine  Turbine blade  Cross ribs  Response surface methodology  Heat transfer characteristics

摘要:

为了深入了解交错肋进口雷诺数在10⁴量级的换热特性，研究了肋倾角、肋宽与肋间距比和进口雷诺数对交错肋换热特性的影响。基于响应曲面法建立了交错肋回归模型，对数值模拟结果进行分析。研究发现各因素对交错肋换热性能的影响力为：肋倾角>肋宽与肋间距比>进口雷诺数。肋倾角减小，交错肋平均努塞尔数先增大后减小，肋倾角在30°~40°时平均努塞尔数出现极大值，肋倾角太小不利于换热。肋倾角每减小25°时，交错肋流阻系数平均增大10倍；当肋倾角增大时，交错肋流阻系数极大值向低雷诺数方向移动；当肋倾角大于35°时，肋宽与肋间距比和进口雷诺数对交错肋流阻系数影响较小。进口雷诺数与交错肋换热性能参数均呈正相关。交错肋在大肋宽与肋间距比、小肋倾角时的换热能力更强；在大肋宽与肋间距比、大肋倾角时的综合流动传热性能更好。

Abstract:

For properly understanding the heat transfer characteristics of cross ribs inlet Reynolds number at 10⁴， the effects of rib dip angle，ratio of rib width to pitch and inlet Reynolds number on heat transfer characteristics of cross ribs were investigated.Based on response surface methodology， the regression model was established and the numerical simulation results were analyzed.The influence of various factors on the heat transfer performance of cross ribs is： rib dip angle>rib width to pitch ratio>inlet Reynolds number.When the rib dip angle decreases， the average Nusselt number of cross ribs increases first and then decreases， and the average Nusselt number has a maximum value between the rib angle at 30°~40°.Too small rib angle is not conducive to heat transfer.When the rib dip angle decreases by 25° each time， the flow resistance coefficient of cross ribs increases by 10 times.When the rib dip angle increases， the maximum value of cross ribs flow resistance coefficient moves to the direction of low Reynolds number.When the rib dip angle is greater than 35°， the rib width to pitch ratio and the inlet Reynolds number have little influence on the flow resistance coefficient of cross ribs.The inlet Reynolds number is positively correlated with the heat transfer performance parameters of cross ribs.The heat transfer capability of the cross ribs is stronger when the rib width to pitch ratio is larger and the rib dip angle is smaller.The comprehensive flow heat transfer performance is better when the rib width to pitch ratio and the rib dip angle is large.