# Angle-Regulating Rule of Guide Vanes of Variable Geometry Turbine Adjusting Mechanism
## 1 Introduction
It was significant to explore effective cooling methods to lower the turbine blade temperature [9] to ensure the gas turbine's safe and stable operation. [PERSON] et al. [10] and [PERSON] et al. [11] studied the impact of cooling and heat transfer characteristics in the turbine guide van cavity. A numerical simulation of multihole impingement cooling of a turbine guide van cavity [12] with a complex pin fin structure was conducted. [PERSON] et al. [13] carried out a numerical simulation of a radial intake chamber with guide vanes with self-guide grooves. Guide vanes could improve and enhance the flow and efficiency of the airflow within the compressor. [PERSON] et al. [14] developed a 3D printed model with variable geometry turbine static components, blades, and the volute. Moreover, a numerical simulation study of the model was conducted. The effect of tip clearance on tip leakage flow was also studied. In addition, the increase in the clearance radius led to a disorderly flow in the impeller [15]. The total dissipation rate on the impeller suction side and near the impeller inlet increased with the backflow clearance radius, but that on the impeller [16] suction side decreased with the increase of the backflow clearance radius. The total dissipation rate of the guide vane's suction side and the outlet passage's wall decreased with the increased backflow clearance radius. [PERSON] et al. [17] studied the effect of the sealing chamber leakage flow rate on the performance of aviation engines. They found that when the sealing tooth gap span ratio increased by 1%, the total pressure ratio decreased by 2.6%, and the efficiency decreased by 0.6%. The leakage flow rate of the sealing chamber significantly impacted the engine's overall performance. [PERSON] et al. [18] proposed that variable geometry systems had great potential due to enhanced thermal management and flow control. Variable burner cooling and variable area nozzle (VAN) systems could improve gas turbine performance and reduce pollutant emissions. [PERSON] et al. [19] studied three different variable geometric positions and three different turbine speeds of a two-stage system. The result proposed a new idea for turbines with variable blade geometry to solve the problem of low turbine efficiency [20]. [PERSON] et al. [21] conducted experimental research on turbulent eddies behind an axial flow fan installed in a pipeline on a test bench with a free inlet and a pipeline outlet. Turbulent vortices in many turbine systems [22] consumed enormous amounts of energy. The variable guide vane structure was applied in compressors and gas turbines and was widely used in water turbines. [PERSON] et al. [23] found that high-amplitude and high-frequency pressure fluctuations caused by rotor-stator interaction (RSI) had become the primary hydraulic excitation source of the unit structure, which might cause severe vibration and fatigue damage to structural components, seriously affecting the safe operation of the unit. [PERSON] et al. [24] studied the effect of eight different inlet slopes of guide vanes on the performance of axial flow pumps. The numerical simulation results were verified through experiments [25]. The numerical simulation results indicated that reducing the height of the guide vane hub could improve the head and efficiency of the axial flow pump. [PERSON] et al. [26] proved this concept by introducing a variable guide vane system into the draft tube of the high-head Francis turbine. A variable guide vane structure was added to the draft tube of the hydraulic turbine. The guide vane could rotate \(\pm 45^{\circ}\) around the shaft. This structure could reduce pressure pulsation. In contrast, it had a negligible impact on the hydraulic performance of the hydraulic turbine. [PERSON] et al. [27] studied the performance characteristics of the Francis turbine at different guide vane openings. They found the optimal operating point based on the number of units. At present, variable geometry turbines are still a new research direction. There is broad research space.