scholarly journals Design and Optimization of Lug Bracket Assembly

2021 ◽  
Vol 13 (1) ◽  
pp. 55-67
Author(s):  
G. GOWTHAM ◽  
G. SHIVA SAM KUMAR SHIVA SAM KUMAR ◽  
AASA DARA
Keyword(s):  
Static Loading ◽  
Design Procedure ◽  
Initial Model ◽  
Stress Concentrations ◽  
Fighter Aircraft ◽  
Design And Optimization ◽  
High Speeds ◽  
Cantilever Structure ◽  
Standard Design ◽  
Optimized Model

An aircraft is an advanced mechanical structure made by man which has been dominating the skies from the early 19th centuries. It has been used for transportation of cargo/ passengers from one place to another in a shorter period of time. Advances in aeronautics lead to the development of fighter aircrafts with exciting and dominating characteristics. A fighter aircraft is to be designed in such a way that it can withstand heavy loadings on the wing due to its high manoeuvrability. A fighter aircraft is designed to be marginally unstable, which makes control easier and better during manoeuvrability at high speeds, but in this state there is a heavy fluctuating load acting on the wing. The wing is connected to the fuselage using wing fuselage lug attachment bracket. Since the wing is a cantilever structure, the load acting on the wing is concentrated on the hinge (lug bracket assembly). In this paper, a lug bracket is designed according to the standard design procedure and is validated using Finite Element Methods to ensure the static loading capability and stress concentrations in lug bracket. The validated model has been optimized using Altair Optistruct. The optimized model has been validated under static loading condition for the stress concentration and displacement and is compared with initial model in order to study and understand its behaviour under various conditions.

scholarly journals Design and Optimization of a Composite Canard Control Surface of an Advanced Fighter Aircraft under Static Loading

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Sachin Shrivastava ◽  
P.M. Mohite
Keyword(s):  
Static Loading ◽  
Fiber Composite ◽  
Design Procedure ◽  
Optimization Procedure ◽  
High Strength ◽  
Control Surface ◽  
Carbon Fiber Composite ◽  
Ferrous Alloys ◽  
Fighter Aircraft ◽  
Elitist Strategy

AbstractThe minimization of weight and maximization of payload is an ever challenging design procedure for air vehicles. The present study has been carried out with an objective to redesign control surface of an advanced all-metallic fighter aircraft. In this study, the structure made up of high strength aluminum, titanium and ferrous alloys has been attempted to replace by carbon fiber composite (CFC) skin, ribs and stiffeners. This study presents an approach towards development of a methodology for optimization of first-ply failure index (FI) in unidirectional fibrous laminates using Genetic-Algorithms (GA) under quasi-static loading. The GAs, by the application of its operators like reproduction, cross-over, mutation and elitist strategy, optimize the ply-orientations in laminates so as to have minimum FI of Tsai-Wu first-ply failure criterion. The GA optimization procedure has been implemented in MATLAB and interfaced with commercial software ABAQUS using python scripting. FI calculations have been carried out in ABAQUS with user material subroutine (UMAT). The GA's application gave reasonably well-optimized ply-orientations combination at a faster convergence rate. However, the final optimized sequence of ply-orientations is obtained by tweaking the sequences given by GA's based on industrial practices and experience, whenever needed. The present study of conversion of an all metallic structure to partial CFC structure has led to 12% of weight reduction. Therefore, the approach proposed here motivates designer to use CFC with a confidence.

Analysis of Stresses and Strains in Packed Stuffing-Boxes

2014 ◽  
Author(s):  
Mehdi Kazeminia ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Design Procedure ◽  
Standard Test ◽  
Packing Material ◽  
Test Procedures ◽  
Analytical Methodology ◽  
Packing Materials ◽  
Standard Design ◽  
Packing Rings ◽  
Leak Tightness ◽  
Side Walls

Packed stuffing-boxes are mechanical sealing systems that are extensively used in pressurized valves and pumps. Yet there is no standard design procedure that could be used to verify their mechanical integrity and leak tightness. It is only recently that standard test procedures to qualify the packing material have been suggested for adoption in both North America and Europe. While the packing contact stress with the side walls is predictable using existing models there is no analytical methodology to verify the stresses and strains in the stuffing-box housing. This paper presents an analytical model that analyzes the stresses and strains of all the stuffing box components including the packing rings. The developed model will be validated both numerically using FEM and experimentally on an instrumented packed stuffing box rig that is specially designed to test the mechanical and leakage performance of different packing materials.

scholarly journals A New Design Procedure for Rotor Laminations of Synchronous Reluctance Machines with Fluid Shaped Barriers

Electronics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 134
Author(s):  
Federica Uberti ◽  
Lucia Frosini ◽  
Loránd Szabó
Keyword(s):  
Finite Element ◽  
Design Procedure ◽  
Optimization Procedure ◽  
Torque Ripple ◽  
Stator Winding ◽  
Post Processing ◽  
Processing Stage ◽  
Synchronous Reluctance Machine ◽  
Design And Optimization ◽  
Reluctance Machine

A new procedure for the design and optimization of the rotor laminations of a synchronous reluctance machine is presented in this paper. The configuration of the laminations is symmetrical and contains fluid-shaped barriers. The parametrization principle is used, which executes variations in the lamination geometry by changing the position, thickness and shape of the flux barriers. Hence, the optimization procedure analyzes the various configurations through finite element simulations, by means of the communication between MATLAB and Flux 2D. In the post processing stage, the best geometry which optimizes mean torque, torque ripple, efficiency and power factor is selected. Once the best rotor configuration is defined, further investigations allow improving its performance by modifying the current angle, the stator winding and the thickness of the radial ribs.

scholarly journals Estimation of the Effects of Distortion on the Longitudinal Stability of Swept Wing Aircraft at High Speeds (Sub-Critical Mach Numbers)

1954 ◽  
Vol 5 (5) ◽  
pp. 280-322
Author(s):  
B. S. Campion
Keyword(s):  
Control Circuit ◽  
Superposition Method ◽  
Swept Wing ◽  
Longitudinal Stability ◽  
Fighter Aircraft ◽  
High Speeds ◽  
Mach Numbers ◽  
The Individual ◽  
And Control

SummaryThe effects of distortion on the longitudinal stability of swept wing aircraft at high speeds (sub-critical Mach numbers) are considered on a quasi-static basis. The method is based on the theory of Gates and Lyon but involves some extension of this theory.The treatment of wing distortion is considered in some detail and the effects of built-in twist and camber and wing weight are included, using the so-called superposition method. The application of the analysis of Lyon and Ripley for investigating fuselage, tail and control circuit distortion is suggested, but means of modifying and simplifying this procedure where desirable are put forward.The analysis is illustrated by means of a simple example of a swept wing fighter aircraft for which wing, fuselage and tail distortion effects are considered, and the results are discussed with reference to the individual and combined distortion effects, as well as the effect of compressibility.

Optimisation of Design and Operation Parameters for Multicomponent Separation via Improved Lewis-Matheson Method

2017 ◽  
Vol 12 (4) ◽  
Author(s):  
Ching Ching Tiong ◽  
Jobrun Nandong
Keyword(s):  
Design Procedure ◽  
Problem Formulation ◽  
Computational Time ◽  
Separation And Purification ◽  
Efficient Design ◽  
Feed Composition ◽  
Design And Optimization ◽  
Purification Technique ◽  
Stage Matching ◽  
Matching Criteria

AbstractDistillation is the most commonly used separation and purification technique in the chemical and allied industries despite that it has been known as the most energy-consuming unit in process industry. The need to reduce this energy consumption has become one of the important focuses in the efficient design and optimization of distillation processes. In the present work, we propose an improved Lewis-Matheson stage-by-stage procedure by incorporating the Fenske equation to enhance the estimation of the non-key component distributions, and thus avoiding infeasible solutions to the stage-by-stage system of equations of mass and energy balances. A modified theta method is also included in the design procedure to satisfy the feed stage matching criteria which help reduces the computational time while increasing the accuracy of feed composition matching. By using the proposed modified Lewis-Matheson method, an optimization is conducted in Matlab environment where the problem formulation takes into account both sets of design and operating parameters with specified product purity as the constraint. The objective function of the optimization is to minimize the Total Annualized Cost (TAC), which includes both capital and operating costs. The effectiveness of the proposed design procedure is demonstrated using an industrial-scale natural gas liquids (NGLs) depropanizer fractionation unit.

Inverse Design and Optimization of a Return Channel for a Multistage Centrifugal Compressor

2004 ◽  
Vol 126 (5) ◽  
pp. 799-806 ◽  
Author(s):  
A´rpa´d Veress ◽  
Rene´ Van den Braembussche
Keyword(s):  
Design Method ◽  
Design Procedure ◽  
Leading Edge ◽  
Secondary Flows ◽  
Inverse Design ◽  
Navier Stokes ◽  
Design And Optimization ◽  
The Cross ◽  
Return Channel ◽  
The Impact

The design and optimization of a multistage radial compressor vaneless diffuser, cross-over and return channel is presented. An analytical design procedure for 3D blades with prescribed load distribution is first described and illustrated by the design of a 3D return channel vane with leading edge upstream of the cross-over. The analysis by means of a 3D Navier–Stokes solver shows a substantial improvement of the return channel performance in comparison with a classical 2D channel. Most of the flow separation inside and downstream of the cross-over could be avoided in this new design. The geometry is further improved by means of a 3D inverse design method to smooth the Mach number distribution along the vanes at hub and shroud. The Navier–Stokes analysis shows a rather modest impact on performance but the calculated velocity distribution indicates a more uniform flow and hence a larger operating range can be expected. The impact of vane lean on secondary flows is investigated and further performance improvements have been obtained with negative lean.

Effect of Temperature on Damping in Shell and Tube Heat Exchangers

2008 ◽  
Author(s):  
Ali Roheim El-Ghalban ◽  
Qamar Iqbal ◽  
Shahab Khushnood ◽  
M. Arshad Qureshi ◽  
M. Shahid Khalil
Keyword(s):  
Heat Exchangers ◽  
Design Procedure ◽  
Design Guidelines ◽  
Nuclear Industry ◽  
Major Influence ◽  
Shell Side ◽  
Flow Induced Vibration ◽  
Standard Design ◽  
Shell And Tube ◽  
Operating Temperatures

Flow-induced vibration in heat exchangers has been a key source of concern in the process, power generation and nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported. Design of tube bundles with loosely supported tubes in baffles for process shell and tube heat exchanger and steam generator needs estimation of energy dissipation mechanisms or damping for a safer and long term operation. Damping has a major influence on the flow induced vibrations and is dependant on a variety of factors such as mechanical properties of the tube material, geometry and number of intermediate supports, the physical properties of shell-side fluid, type of tube motion, tube frequency, shell-side temperature etc. Various damping mechanisms have been identified and quantified such as Friction damping, Viscous damping, Squeeze film damping, Support damping and Two-Phase damping which affect the performance with respect to flow induced vibration design, including standard design guidelines. But generally the effects of the higher operating temperatures on the various damping mechanisms are neglected in the general design procedure. The operating temperatures play significant role on the contribution of various damping mechanisms. The current paper focuses on the thermal aspects of damping mechanisms subjected to single phase cross-flow in process heat exchangers and formulates the design guidelines for safer design based on experimental and empirical formulations. The research results show that he increase in the temperature results in the increase of the damping. Moreover it found that the natural frequency is higher for lower mass flow rate and lower working pressures and lower temperatures.

scholarly journals Design and Optimization of an Exhaustive Muffler and Experimentation to reduce Emission using Fly ash

2019 ◽  
Vol 8 (3) ◽  
pp. 94-100
Keyword(s):  
Fly Ash ◽  
Structural Analysis ◽  
Safety Factor ◽  
Catalytic Converter ◽  
Equivalent Stress ◽  
Slight Modification ◽  
Fuel Mixture ◽  
Gas Analyzer ◽  
Initial Model ◽  
Design And Optimization

Exhaust gases from the combustion of the air-fuel mixture are reduced to non-harmful gases before releasing them into the atmosphere using a catalytic converter. Exhaust muffler or silencer are used to reduce noise and vibrations level due to the expansion of gases. In this research, a novel muffler is designed for 4-stroke, 125cc single-cylinder petrol engine and structural analysis are carried out for optimization using ANSYS Static Structural solver. The muffler is subjected to various pressure loads, acceleration loads, and load due to self-weight. Fatigue analysis is further carried out using stress-life approach and mean Soderberg theory of failures to determine Life, Damage, Safety factor, Biaxiality Indication, and Alternating equivalent stress under dynamic loading. Experimental analysis is carried out using an optimized muffler with fly ash as a catalyst to determine the reduction in emission. Structural analysis of the initial model was optimized by slight modification in design which reduced total deformation from 0.0379 mm to 0.0374 mm and equivalent stress from 52.878 Mpa to 50.969 Mpa. The safety factor was also increased from 1.6302 to 1.6902. Experimental results using Gas analyzer used for emission readings have shown a reduction in the emission of carbon monoxide and hydrocarbons by 21.06% and 23.07% respectively as compared to a standard muffler.

Design and Optimization of Microwave Circuits and Devices with the Particle Swarm Optimizer

2012 ◽  
pp. 1-17
Author(s):  
Massimo Donelli
Keyword(s):  
Particle Swarm ◽  
Microwave Circuits ◽  
Computational Time ◽  
Microwave Devices ◽  
Particle Swarm Optimizer ◽  
Computational Burden ◽  
Design And Optimization ◽  
Standard Design ◽  
Cad Tool ◽  
Microwave Cad

In this chapter, a methodology for the unsupervised design of microwave devices, circuits, and systems is considered. More specifically, the application of the Particle Swarm Optimizer and its integration with electromagnetic simulators is discussed in the framework of the microwave circuits and devices design and optimization. The idea is to automatically modify the characteristics of the device in an unsupervised way, with the goal of improve the device performances. Such kind of CAD tool could be the solution to reduce the time to market and keep the commercial predominance, since they do not require expert microwave engineers and it can reduce the computational time typical of the standard design methodologies. To assess the potentialities of the proposed method, a selected set of examples concerning the design of microwave planar devices such as filters, splitters, and other microwave devices under various operative conditions and frequency bands are reported and discussed. The chapter also includes a brief discussion concerning different strategies, such as parallel computation, to reduce the computational burden and the elaboration time. The obtained results seem to confirm the capabilities of the proposed method as effectiveness microwave CAD tool for the unsupervised design of microwave devices, circuits, and systems. The chapter ends with some conclusions and considerations related to ideas for future works.

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