# Influence of Inflow Turbulence on the Flow Characteristics around a Circular Cylinder
## 7 Conclusions  
This paper has studied the characteristic parameters of mean wind pressure coefficient distribution on cylindrical surface, drag coefficient and lift coefficient for different Reynolds numbers and turbulence intensities. The results are compared with the results obtained by other researchers. The correlation of wind pressure on a cylindrical surface is also studied. In the smooth flow, the wind pressure coefficient of the base region increases with the increase of Reynolds number and remains basically unchanged when the Reynolds number is in the supercritical regime. In the turbulent flow, the wind pressure coefficient of the base region increases first and then decreases with the increase in Reynolds number. This is close to the results in the smooth flow when the Reynolds number is in the supercritical regime and far greater than results in the smooth flow when the Reynolds number is in the subcritical and critical regimes. In the smooth flow, the position of separation point is about \(80^{\circ}\) when the Reynolds number is in the subcritical regime; it suddenly moves back in the critical regime and is basically stable at about \(140^{\circ}\) in the supercritical regime. However, in the turbulent flow, the position of the separation point is basically around \(140^{\circ}\) regardless of the Reynolds number regime. In the smooth flow, the minimum wind pressure coefficient is almost constant in the subcritical regime: the value is about \(-1.0\). It suddenly decreases in the critical regime and is basically constant in the supercritical regime, the value of which is about \(-2.4\). In the turbulent flow, the minimum wind pressure coefficient decreases in the subcritical regime as the Reynolds number increases and remains constant in the critical and supercritical regimes, with a value of approximately \(-2.3\).  
Compared with characteristics in the smooth flow, turbulence will cause the critical Reynolds number to move to a smaller Reynolds number while the critical regime of the Reynolds number and its characteristics are not obvious. The minimum drag coefficient in the turbulent flow is basically constant at about 0.4 and is not affected by turbulence intensity. The lift coefficient in turbulent flow is basically zero, however, in a smooth flow; the lift coefficient suddenly increases when the Reynolds number is in the critical regime. The fluctuating values of the lift coefficient of the smooth flow are greater than the values in the turbulent flow under the same Reynolds number.  
In the smooth flow, the laminar flow separation shows a strong positive correlation between the wind pressure points on the same side. However, the turbulent separation shows a strong correlation between the measured points in the region of about \(0^{\circ}\)-\(120^{\circ}\) and \(120^{\circ}\)-\(180^{\circ}\) on the same side; the correlation between the two regions is weak. The turbulent flow basically shows the correlation characteristics of turbulent separation.  
Conceptualization, G.S.; Investigation, J.Y. and Y.G.; Methodology, G.S. and Y.X.; Data curation, J.Y.; Supervision, W.L.; Writing--Original draft, J.Y.; Writing--Review & editing, G.S. This research was funded by the National Natural Science Foundation of China (Grant No. 51838012). The authors declare no conflict of interest.