Innovative Turbine Blade Tips to Reduce Tip Leakage Flow

Figure 1: Turbine blade with squealer tips.

400 words / 2 minutes read

Revolutionary turbine blade tip designs are critical for minimizing tip leakage losses in gas turbines. Several innovative designs, such as flat tips, squealer tips, tips with winglets and honeycomb cavities, have shown the potential to mitigate this problem.

Importance of Reducing Blade Tip Leakage Losses in Turbine Blades

Turbine efficiency and performance can be improved by minimizing tip leakage losses in the blades. These losses are an unavoidable result of the flow passing through the narrow gap between the blade tip and shroud, mixing with the main flow and causing disruption in the flow pattern. The proportion of tip leakage losses to total aerodynamic loss can be as high as one-third, a significant amount that can reduce turbine output.

By reducing tip leakage losses, a turbine can operate more efficiently, resulting in lower fuel consumption, fewer emissions, and ultimately lower operating costs. In addition, it can prolong the lifespan of the turbine by reducing wear and tear on the blades and other components. Therefore, minimizing tip leakage losses is essential for optimizing the turbine’s performance and ensuring its long-term sustainability.

**Figure 2:** Structured multiblock mesh for a turbine blade with Winglet. Image source – *Reference Paper*

The Impact of Blade Tip Clearance on Gas Turbine Performance

Gas turbines use tip clearances between the turbine blade tip and the stationary casing to prevent rubbing and accommodate expansions. Unfortunately, these clearances create aerodynamic losses and leakage, which reduce turbine efficiency and work output. Leakage through the clearance also adds extra heat, increasing the tip metal temperature and thermal load. In high-performance turbines, the tip leakage flow is intense, significantly impacting turbine performance. As a result, developing new or enhanced designs that cool the blade tip and seal the leakage flow is crucial. Proper tip clearance control is vital to optimizing gas turbine performance and output.

Improving Turbine Efficiency: Exploring Innovative Blade Tip Design Features

Over the years, various tip design features have been proposed as a solution, like flat tips, squealer tips, tips with winglets and honeycomb cavities, etc. Unfortunately, less clarity exists in understanding the dominant flow structure, affecting these tip designs’ aerodynamic benefits. Hence, numerical and experimental studies are conducted to study the effects of different tip designs on the aerodynamic performance and cooling requirements.

To learn more about innovative tip designs and their impact on turbine performance, consider reading these three articles: