Gas Turbine Research Establishment is a laboratory of the Defence Research and Development Organisation . Located in Bangalore, its primary function is research and development of aero gas-turbines for military aircraft. As a spin-off effect, GTRE has been developing marine gas-turbines also. Wikipedia.
Suryakumar S.,Indian Institute of Technology Hyderabad |
Karunakaran K.P.,Indian Institute of Technology Bombay |
Bernard A.,Ecole Centrale Nantes |
Chandrasekhar U.,Gas Turbine Research Establishment |
And 2 more authors.
CAD Computer Aided Design | Year: 2011
Hybrid Layered Manufacturing is a Rapid Manufacturing process in which the metallic object is built in layers using weld deposition. Each layer built through overlapping beads is face milled to remove the scales and scallops and ensure Z-accuracy. The formations of single beads and overlapping multiple beads are modeled in this paper. While the individual bead's geometry is influenced by the size of the filler wire and the speeds of the wire and torch, the step over increment between the consecutive beads additionally comes into the picture for the multiple bead deposition. These models were validated experimentally. They are useful not only to predict the bead's shape but also to optimize the three process parameters. © 2010 Elsevier B.V. All rights reserved.
Rajendran R.,Gas Turbine Research Establishment
Engineering Failure Analysis | Year: 2012
The components of a gas turbine operate in an aggressive environment where the temperature of service varies from ambient to near melting point of materials which introduce a variety of degradation on the components. Some components that lose their dimensional tolerance during use require repair and refurbishment when high cost replacement is avoidable. Erosion of fly ash and sand particles damages compressor blades which cause engine failure at an early stage. Dovetail roots of the compressor blades are subjected to fretting fatigue due to the oscillatory motion caused by vibration. Casing of the compressor comes in contact with rotating blades due to shaft misalignment, ovality of the casing and or inadequate clearance which cause blade and casing damage. Close clearance control that has bearing on the efficiency of the engine is therefore required in addition to preventing fire where titanium to titanium rubbing might occur. Wear out of the several contact surfaces which undergo rotating and reciprocating motion occur during the running of the engine need protection. Hot gases that are produced by burning the contaminated fuel in the combustion chamber will cause oxidation and corrosion on their passage. In the hot section rotating and stationary components need thermal insulation from higher operating temperature leading to enhanced thermodynamic efficiency of the engine. This wide range of functional requirements of the engine is met by applying an array of coatings that protect the components from failures. Current overview, while not aiming at deeper insight into the field of gas turbine coatings, brings out a summary of details of these coatings at one place, methods of application and characterization, degradation mechanisms and indicative future directions which are of use to a practicing industrial engineer. © 2012 Elsevier Ltd.
Pustode M.D.,Indian Institute of Technology Bombay |
Raja V.S.,Indian Institute of Technology Bombay |
Paulose N.,Gas Turbine Research Establishment
Corrosion Science | Year: 2014
The hot salt stress corrosion cracking (HSSCC) behaviour of a near α titanium alloy, IMI 834, was studied using slow strain rate test method in the temperature range 250-450. °C. The alloy was found to be susceptible to HSSCC at 300. °C and above; and the susceptibility increased with an increase in the test temperature. The secondary cracks grew exponentially with temperature. HSSC cracks initiated at α/β interfaces and grew across the primary α grain and along the α/β interfaces. © 2014 Elsevier Ltd.
Karthikeyan S.,Annamalai University |
Balasubramanian V.,Annamalai University |
Rajendran R.,Gas Turbine Research Establishment
Ceramics International | Year: 2014
Plasma-sprayed yttria-stabilized zirconia (YSZ) coating has been considered to be a good protective coating material for high-temperature applications on account of its superior properties and life cycle costs. However, thermal barrier coatings (TBCs) have engineering reliability problems in tailoring the microstructure and mechanical properties towards achieving both prime reliance and manufacturing reproducibility. In this work, empirical relationships were developed to estimate TBCs performance characteristics (porosity and microhardness) by incorporating independently controllable atmospheric plasma spray operational parameters (input power, standoff distance and powder feed rate) using the response surface methodology (RSM). A central composite rotatable design with three factors and five levels was chosen to minimize the number of experimental conditions. Within the scope of the design space, the input power and the standoff distance appeared to be the most significant two parameters affecting the coating quality characteristics among the three investigated process parameters. Further, correlating the spray parameters with coating properties enables the identification of characteristics regime to achieve desired quality of YSZ coatings. © 2013 Elsevier Ltd and Techna Group S.r.l.
Mahobia G.S.,Indian Institute of Technology BHU Varanasi |
Paulose N.,Gas Turbine Research Establishment |
Singh V.,Indian Institute of Technology BHU Varanasi
Journal of Materials Engineering and Performance | Year: 2013
This investigation was undertaken to evaluate oxidation and hot corrosion behavior of the Fe-Ni-based superalloy IN718, at 550 and 650 C, to explore its performance as turbine engine components under marine environment. Uncoated and different salt-coated samples (100 wt.% NaCl, 75 wt.% Na2SO 4 + 25 wt.% NaCl, and 90 wt.% Na2SO4 + 5 wt.% NaCl + 5 wt.% V2O5) were exposed in air at 550 and 650 C under cyclic heating and cooling for 100 h. Weight gain was studied for both uncoated and salt-coated samples. X-ray diffraction, scanning electron microscopy, and electron dispersive spectroscopy were used to characterize the oxidation and corrosion products. A possible mechanism of corrosion, based on the corrosion compounds, is discussed. The variation in weight gain with time showed a parabolic growth of oxides. Coating with NaCl was found to be detrimental both at 550 C as well as 650 C. On the other hand, the salt mixture of NaCl and Na2SO4 had no effect at 550 C; however, it was detrimental at higher temperature of 650 C. Coatings of salt mixture of Na 2SO4, NaCl, and V2O5 caused very slow oxidation at both the temperatures. Increase in thickness of salt coating was observed to enhance the rate of hot corrosion. Among the three types of salt coatings, the coating of NaCl was found to be most damaging both at 550 and 650 C. © 2013 ASM International.