International Journal of Trend in Scientific Research and Development (IJTSRD) Volume 5 Issue 1, November-December 2020 Available Online: www.ijtsrd.com e-ISSN: 2456 – 6470 @ IJTSRD | Unique Paper ID – IJTSRD38000 | Volume – 5 | Issue – 1 | November-December 2020 Page 603 Effect of Dimple/ Protrusion Shape on The Cooling Performance of The Turbine Blade Using CFD Prof. Amol Kumar Tripathi 1 , Neha Verma 2 1 Assistant Professor, 2 M.Tech Scholar 1,2 Rewa Institute of Technology, Rewa, Madhya Pradesh, India ABSTRACT It is well understood that one way to improve a gas turbine engine's power output and thermodynamic performance is to increase the temperature of the turbine inlet (TIT). The inlet temperature should be gradually elevated to higher targets to pursue greater control. However, with the rise in blade inlet temperature, the heat applied to the blade increases, and the permissible melting temperature of materials increases at a slower rate. This implies that the inlet temperature of the turbine blade will exceed the melting temperature of the material by more than 500℃ . Thus, cooling turbine blades for a safe and long-lasting operation is important. To lower the temperature of the blade content below its melting point, different internal and external cooling techniques are employed. . In recent years, in the tip region of the turbine blade, multiple augmentation devices such as fins, ribs, pins, and dimples / protrusions have gained a lot of attention to enhance heat transfer. With increasing inlet temperature of the turbine, pin fin arrays cannot satisfy the need of the cooling alone. To be paired with the pin fin arrays, several more methods are also added. With slight loss of pressure, dimples and protrusions are fine options. In this present work, the numerical approach is used to investigate the influence of dimples or protrusions shape on the cooling of the turbine blade. The ANSYS 17.0 simulation software was used. The results of this study show that the , due to flow acceleration, increase in impingement area and shrinkage of the flow recirculation region within the dimple, pin fin- dimple wedge duct with triangular shape dimples/protrusions provides improved heat transfer enhancement. KEYWORDS: Gas turbine, Turbine inlet temperature, turbine blade cooling, internal convective cooling, Pin fin cooling, dimples/protrusions shape, and CFD How to cite this paper: Prof. Amol Kumar Tripathi | Neha Verma "Effect of Dimple/ Protrusion Shape on The Cooling Performance of The Turbine Blade Using CFD" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-1, December 2020, pp.603-610, URL: www.ijtsrd.com/papers/ijtsrd38000.pdf Copyright © 2020 by author(s) and International Journal of Trend in Scientific Research and Development Journal. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0) (http://creativecommons.org/licenses/by/4.0) I. INTRODUCTION Turbines play a very important role in the technologically sophisticated industries today. To cope up with the current demands of higher power generation, improved thermal efficiency and to eventually improve the overall performance of the turbine, we need to operate on very high turbine inlet temperature (TIT). Studies show that only a decrease of will affect the overall turbine output. However, the disadvantage of the very high inlet temperature is that it limits the life of blades and valves and often reaches the blade melting point. Diverse other factors besides the melting point of a blade steel, such as the creep strain, centrifugal and rotational stress, produced while the turbine blade operates in practise, bound TIT. Figure 1. Development during the last 60 years of turbine cooling system. The continuous distribution and physical distortion under constant load (creep) increases the rotational stresses induced by a blade breakdown when the blade is in operation. It is found that in recent years, the turbine blades and vanes have been shielded from such high TIT in the context of modern cooling concepts. The purpose of the turbine blade cooling is to reduce the blade temperature without reducing the turbine's efficiency and output. Air or liquid may either be used as a means for cooling. It looks very enticing with the use of a liquid coolant like water because the water's thermal potential is high and the chances of an evaporative refreshment are minimal, but it can leak and cause corrosion, shock and further decrease the life of the blade. As a cooling medium, the new cooling systems use cold air from the compressor unit as a way of mixing quickly with the main flow of hot gas in the turbine. In gas turbine blades, several cooling methods are employed; convection, film, transpiration cooling, cooling effusion, pin fin cooling, etc. fall under the divisions of internal and external cooling. Although every approach has its variations, they both work to eliminate the heat from the turbine blades using colder air (often bleeding from the compressor). IJTSRD38000