Design Optimization of T-Root Geometry of a Gas Engine HP Compressor Rotor Blade for Lifing the Blade Against Fretting Failure

2016 ◽  
Author(s):  
Kumar K. Gowda ◽  
S. L. Ajit Prasad ◽  
Vinayaka Nagarajaiah
Keyword(s):  
Design Optimization ◽  
Turbine Blades ◽  
Wake Flow ◽  
Element Analysis ◽  
Gas Engine ◽  
Blade Root ◽  
Compressor Rotor ◽  
Blade Optimization ◽  
Engine Failure ◽  
Practical Geometry

Stress Concentration Factor (SCF) is significant in machine elements as it gives rise to localised stresses which lead to peak stresses introducing cracks which propagate further and hence the component fails before the desired design life. Turbine blades are subjected to high centrifugal stresses and vibratory stresses in a Gas Engine HP Rotor. The vibratory stresses arise due to air wake flow excitations called Nozzle Passing Frequency (NPF). Hence, Turbomachinery industry calls for an optimum structurally rigid blade root geometry. An optimum blade root was defined, as a root with practical geometry, which when loaded returns the minimum fillet SCF. In the present work an approach has been done for design optimization of fillet stresses at sharp edges of T-root blade, optimization of platform dimensions, shank dimensions, root land dimensions and to ensure that stress distribution is uniformly spread along the filleted width of the root land on both sides of the blade, which otherwise will lead to crack initiation, propagation and hence, fretting failure at blade root lands. This may further lead to blade lift and effect on stage and overall gas engine failure over a period of cycles. Hence, a special attention is made on SCF of the T root -blade which fails and to guarantee for safe and reliable operation under all possible service conditions. Finite Element Analysis (FEA) is used to determine the fillet stresses and Peterson’s SCF chart is effectively utilized to modify the blade root. The root is modified due to the difficulty in manufacturing the butting surface of the tang which grips the blade to the disk crowns having small contact area. The blade height is suitably designed using Campbell diagram by ensuring the working frequency is well within 6e excitations for the specified operating speeds. Hence, increasing the life of the HP compressor blade.

Rubber Composition–Properties Relationships during Tire Numerical Simulation and Design Optimization

2017 ◽  
Vol 45 (1) ◽  
pp. 71-84 ◽  
Author(s):  
Alexey Mazin ◽  
Alexander Kapustin ◽  
Mikhail Soloviev ◽  
Alexander Karanets
Keyword(s):  
Numerical Simulation ◽  
Design Optimization ◽  
Strain Tensor ◽  
General Purpose ◽  
Orthogonal Functions ◽  
Element Analysis ◽  
Time Investment ◽  
Footprint Analysis ◽  
Composition Properties ◽  
Nonlinear Elastic

ABSTRACT Numerical simulation based on finite element analysis is now widely used during the design optimization of tires, thereby drastically reducing the time investment in the design process and improving tire performance because it is obtained from the optimized solution. Rubber material models that are used in numerical calculations of stress–strain distributions are nonlinear and may include several parameters. The relations of these parameters with rubber formulations are usually unknown, so the designer has no information on whether the optimal set of parameters is reachable by the rubber technological possibilities. The aim of this work was to develop such relations. The most common approach to derive the equation of the state of rubber is based on the expansion of the strain energy in a series of invariants of the strain tensor. Here, we show that this approach has several drawbacks, one of which is problems that arise when trying to build on its basis the quantitative relations between the rubber composition and its properties. An alternative is to use a series expansion in orthogonal functions, thereby ensuring the linear independence of the coefficients of elasticity in evaluation of the experimental data and the possibility of constructing continuous maps of “the composition to the property.” In the case of orthogonal Legendre polynomials, the technique for constructing such maps is considered, and a set of empirical functions is proposed to adequately describe the dependence of the parameters of nonlinear elastic properties of general-purpose rubbers on the content of the main ingredients. The calculated sets of parameters were used in numerical tire simulations including static loading, footprint analysis, braking/acceleration, and cornering and also in design optimization procedures.

scholarly journals Simulation of Glass Fiber Reinforced Polypropylene Nanocomposites for Small Wind Turbine Blades

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 622
Author(s):  
Yasser Elhenawy ◽  
Yasser Fouad ◽  
Haykel Marouani ◽  
Mohamed Bassyouni
Keyword(s):  
Wind Turbine ◽  
Glass Fiber ◽  
Turbine Blades ◽  
Small Scale ◽  
Fiber Reinforced ◽  
Wind Turbine Blades ◽  
Element Analysis ◽  
Glass Fiber Reinforced ◽  
Horizontal Axis Wind Turbines ◽  
Multi Walled Carbon Nanotubes

This study aims to evaluate the effect of functionalized multi-walled carbon nanotubes (MWCNTs) on the performance of glass fiber (GF)-reinforced polypropylene (PP) for wind turbine blades. Support for theoretical blade movement of horizontal axis wind turbines (HAWTs), simulation, and analysis were performed with the Ansys computer package to gain insight into the durability of polypropylene-chopped E-glass for application in turbine blades under aerodynamic, gravitational, and centrifugal loads. Typically, polymer nanocomposites are used for small-scale wind turbine systems, such as for residential applications. Mechanical and physical properties of material composites including tensile and melt flow indices were determined. Surface morphology of polypropylene-chopped E-glass fiber and functionalized MWCNTs nanocomposites showed good distribution of dispersed phase. The effect of fiber loading on the mechanical properties of the PP nanocomposites was investigated in order to obtain the optimum composite composition and processing conditions for manufacturing wind turbine blades. The results show that adding MWCNTs to glass fiber-reinforced PP composites has a substantial influence on deflection reduction and adding them to chopped-polypropylene E-glass has a significant effect on reducing the bias estimated by finite element analysis.

Studies on Determination of Natural Frequencies of Industrial Turbine Blades

1995 ◽  
Author(s):  
Mahesh M. Bhat ◽  
V. Ramamurti ◽  
C. Sujatha
Keyword(s):  
Steam Turbine ◽  
Dynamic Behavior ◽  
Turbine Blade ◽  
Natural Frequencies ◽  
Complex Structure ◽  
Turbine Blades ◽  
Blade Root ◽  
Steam Turbine Blade ◽  
Manufacturing Tolerances

Abstract Steam turbine blade is a very complex structure. It has geometric complexities like variation of twist, taper, width and thickness along its length. Most of the time these variations are not uniform. Apart from these geometric complexities, the blades are coupled by means of lacing wire, lacing rod or shroud. Blades are attached to a flexible disc which contributes to the dynamic behavior of the blade. Root fixity also plays an important role in this behavior. There is a considerable variation in the frequencies of blades of newly assembled turbine and frequencies after some hours of running. Again because of manufacturing tolerances there can be some variation in the blade to blade frequencies. Determination of natural frequencies of the blade is therefore a very critical job. Problems associated with typical industrial turbine bladed discs of a 235 MW steam turbine are highlighted in this paper.

Temperature Estimation and Life Prediction of Turbine Blades Using Post-Service Oxidation Measurements

1997 ◽  
Vol 119 (4) ◽  
pp. 922-929 ◽  
Author(s):  
V. P. Swaminathan ◽  
J. M. Allen ◽  
G. L. Touchton
Keyword(s):  
Turbine Blades ◽  
Life Assessment ◽  
Depth Of Penetration ◽  
Trailing Edge ◽  
Element Analysis ◽  
Temperature Estimation ◽  
Exposure Temperature ◽  
Cooling Hole ◽  
Surface Metal ◽  
Service Exposure

The depth of internal oxidation and nitridation from the surface of the 16 cooling holes in a first-stage turbine blade was measured by optical microscopy after 32,000 hours of service. Maximum depth of penetration was 15.5 mils (0.4 mm) at the trailing edge hole. An effort was made to predict hole surface metal temperatures based on these measurements using the Arrhenius relationship between time and temperature with depth of oxidation assumed to be parabolic with time. Reasonable correlations were obtained between finite element analysis results and temperature estimates based on the oxidation measurements. In the thickest part of the airfoil, where metal temperature is minimum, intergranular cracks up to 12.6 mils (0.32 mm) in depth were found at the surface of the cooling holes. Measurable oxidation attack was only one to two mils (0.025–0.050 mm). Based on an approximate elastic-relaxation-local inelastic stress analysis, it was calculated that inelastic local strains of over one percent occur at the points of cracking. No cracking was observed in the more heavily oxidized, lower stressed, hotter holes. However, cracking occurred in a trailing edge tip cooling hole when weld repair of the tip squealer was attempted, due to embrittlement and grain boundary oxidation from service exposure. Temperature estimates suitable for life assessment purposes using oxidation measurements appears to be a possible technique that should be further developed and validated.

A Non-Through Silicon Via 1000+ IO Package On Package Solution For Wide IO Applications

2013 ◽  
Vol 2013 (1) ◽  
pp. 000094-000099 ◽  
Author(s):  
Laura Mirkarimi ◽  
Rajesh Katkar ◽  
Ron Zhang ◽  
Rey Co ◽  
Zhijun Zhao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Optimization ◽  
High Yield ◽  
Element Analysis ◽  
Package Design ◽  
Simulation Methodology ◽  
Structural Modifications ◽  
Simulation Tools ◽  
Large Bandwidth

We are developing a new solution for wide I/O package on package applications, which is Bond Via Array (BVA) technology. The prototype vehicle built in this study has 1020 I/O's at a pitch of 0.24 mm with a high aspect ratio of approximately 10:1 and is ≤1.4 mm tall. PoP applications require large bandwidth and thinner packages challenging package developers to address warpage control for high yield processes. The design optimization of this package was established through rigorous finite element analysis of materials selection and structural modifications. The simulation methodology was validated by measuring the warpage as a function of temperature for the experimental prototypes. The details for the simulation and verification processes for the wide I/O process will be discussed. The variation between finite element analysis predictions and the experimental builds was ~10%, which allowed us to complete package design optimization with our simulation tools. The prototype build includes a standard and a low CTE substrate.

scholarly journals Effects of Channel Outlet Configuration and Dimple/Protrusion Arrangement on the Blade Trailing Edge Cooling Performance

2019 ◽  
Vol 9 (14) ◽  
pp. 2900
Author(s):  
Qi Jing ◽  
Yonghui Xie ◽  
Di Zhang
Keyword(s):  
Heat Transfer ◽  
Turbine Blades ◽  
High Heat ◽  
Wake Flow ◽  
Internal Cooling ◽  
Trailing Edge ◽  
Cooling Channels ◽  
High Heat Transfer ◽  
Channel Outlet ◽  
Staggered Arrangement

The trailing edge regions of high-temperature gas turbine blades are subjected to extremely high thermal loads and are affected by the external wake flow during operation, thus creating great challenges in internal cooling design. With the development of cooling technology, the dimple and protrusion have attracted wide attention for its excellent performance in heat transfer enhancement and flow resistance reduction. Based on the typical internal cooling structure of the turbine blade trailing edge, trapezoidal cooling channels with lateral extraction slots are modeled in this paper. Five channel outlet configurations, i.e., no second passage (OC1), radially inward flow second passage (OC2), radially outward flow second passage (OC3), top region outflow (OC4), both sides extractions (OC5), and three dimple/protrusion arrangements (all dimple, all protrusion, dimple–protrusion staggered arrangement) are considered. Numerical investigations are carried out, within the Re range of 10,000–100,000, to analyze the flow structures, heat transfer distributions, average heat transfer and friction characteristics and overall thermal performances in detail. The results show that the OC4 and OC5 cases have high heat transfer levels in general, while the heat transfer deterioration occurs in the OC1, OC2, and OC3 cases. For different dimple/protrusion arrangements, the protrusion case produces the best overall thermal performance. In conclusion, for the design of trailing edge cooling structures with lateral slots, the outlet configurations of top region outflow and both sides extractions, and the all protrusion arrangement, are recommended.

Aerodynamic Design Optimization of an Axial Flow Compressor Rotor

2002 ◽  
Author(s):  
Chan-Sol Ahn ◽  
Kwang-Yong Kim
Keyword(s):  
Design Optimization ◽  
Response Surface ◽  
Computing Time ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Axial Flow ◽  
Navier Stokes ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Design Variables

Design optimization of a transonic compressor rotor (NASA rotor 37) using the response surface method and three-dimensional Navier-Stokes analysis has been carried out in this work. The Baldwin-Lomax turbulence model was used in the flow analysis. Three design variables were selected to optimize the stacking line of the blade. Data points for response evaluations were selected by D-optimal design, and linear programming method was used for the optimization on the response surface. As a main result of the optimization, adiabatic efficiency was successfully improved. It was found that the optimization process provides reliable design of a turbomachinery blade with reasonable computing time.

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