Turbine blades of a gas turbine are responsible for extracting energy from the high temperature, high pressure gases. These blades are operated at elevated temperatures in aggressive environments and are subjected to large centrifugal forces. As many as 42 percent of the failures in gas turbine engines were only due to blading problems and the failures in these turbine blades can have dramatic effect on the safety and performance of the gas turbine engine. In this research paper, an attempt has been made to analyze the failure of gas turbine blade through Mechanical analysis. The blade under investigation belongs to a 30 MW gas turbine engines used in marine applications and is made of Nickel-Base superalloys. Before failure, the turbine blade was operated for about 10000 hours while its service life was expected to be around 15000 hours. Mechanical analysis has been carried out assuming that there might be failure in the blade material due to blade operation at elevated temperature and subjected to large centrifugal forces. The gas turbine blade model profile is generated by using CATIA V5R21software. The turbine blade is analyzed for its thermal as well as structural performance. It was observed that there was no evidence of rubbing marks on the tip section of turbine blade indicating the elongation of the blade is within the safe limit. Maximum stresses and strains are observed near to the root of the turbine blade and upper surface along the blade roots. Maximum temperatures are observed at the blade tip sections and minimum temperature at the root of the blade. Temperature distribution is decreasing from the tip to the root of the blade section. The temperatures observed are below the melting temperature of blade material.

An understanding of flow in long horizontal wells can be an important aspect of reservoir management. In view of this, a comprehensive study was undertaken for a pipe with a diameter of 0.022 m and two perforations; one on the upper surface and the other on the lower surface with 0.006 m diameter and 180° phasing. The flow variations have been related to geometric and operating parameters. To better understand wellbore flow, Computational Fluid Dynamics CFD simulations (ANSYS CFX-13) have been used to simulate the flow at the wellbore to calculate the pressure drop, wall shear stress and turbulence kinetic energy etc. Using RNG k ε − model to predict the flow behavior of turbulent pipe flow with the radial flow through perforations in the pipe wall. Comparison CFD results with the other researchers agree with them in relation to the behavior of wall shear stress, pressure drop etc.

High pressure temperature (HPT) turbine blade is the most important component of the gas turbine and failures in this turbine blade can have dramatic effect on the safety and performance of the gas turbine engine. This paper presents the failure analysis made on HPT turbine blades of 100 MW gas turbine used in marine applications. The gas turbine blade was made of Nickel based super alloys and was manufactured by investment casting method. The gas turbine blade under examination was operated at elevated temperatures in corrosive environmental attack such as oxidation, hot corrosion and sulphidation etc. The investigation on gas turbine blade included the activities like visual inspection, determination of material composition, microscopic examination and metallurgical analysis. Metallurgical examination reveals that there was no micro-structural damage due to blade operation at elevated temperatures. It indicates that the gas turbine was operated within the designed temperature conditions. It was observed that the blade might have suffered both corrosion (including HTHC & LTHC) and erosion. LTHC was prominent at the root of the blade while the regions near the tip of the blade were affected by the HTHC. It could be concluded that the turbine blade failure might be caused by multiple failure mechanisms such as hot corrosion, erosion and fatigue. Hot corrosion could have reduced the thickness of the blade material and thus weakened the blade. This reduction of the blade thickness decreases the fatigue strength which ultimately led to the failure of the turbine blade.

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Tribological properties of rapid solidified hyper eutectic AlSi17Cu3. alloy were investigated under different loading conditions. The alloy was produced by the rheo-stir squeeze casting process with the T-6 condition. Experimental studies were conducted using high frequency linear reciprocating rig (HFRR) with a ball-on-plate geometry. The effect of applied load (10-50 N) on the wear and friction (COF) coefficients were studied under dry, lubricated (SAE15W40), and coated dry (DLC-Star) sliding conditions. For dry and lubricated sliding, COF values of hyper eutectic AlSi17Cu3.5-4Mg0.6-0.8 alloy were 0.26 and 0.042. A lower COF value of 0.013 was recorded with DLC-star (CrN + ac:H) coating under dry condition. Whereas, the least wear coefficient is also observed with DLC-star coating (4.6X10 -5 mm 3 /N.m) compared to the dry and lubricated sliding conditions (2.7X10 -3 mm 3 /N.m and 3.8X10 -4 mm 3 /N.m). The developments in COF and wear coefficients were mainly attributed to the distribution and size of primary Si granules and the formation of transfer layers on the coated surfaces of AlSi17Cu3.5-4Mg0.6-0.8 alloy. Surface morphologies were examined using SEM, AFM, surface roughness profilometer, and advanced metallurgical microscope (AMM) analysis techniques.