scholarly journals Conceptual Design and Feasibility Study of Winged Hybrid Airship

Aerospace ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 8
Author(s):  
Akshay Gangadhar ◽  
Murugaiah Manikandan ◽  
Dushhyanth Rajaram ◽  
Dimitri Mavris
Keyword(s):  
Fitness Function ◽  
Pso Algorithm ◽  
Operating Conditions ◽  
Design Variables ◽  
Optimization Study ◽  
General Constraints ◽  
Five Disciplines ◽  
Potential Benefits ◽  
One Year ◽  
Long Endurance

In recent years, hybrid airships have been identified as promising alternatives for high altitude, long endurance missions. In this study, a design methodology to study the feasibility of a winged hybrid airship powered by solar energy is presented. The proposed methodology involves five disciplines of the airship, viz., geometry, aerodynamics, environment, energy and structures that have been coupled in order to develop an optimum design which incorporates the maximum advantages of the modules. A total of fourteen design variables have been finalized, which are required to carry out the sizing of the envelope, wing, and solar panel layout. The Particle Swarm Optimization (PSO) algorithm is implemented to carry out optimization of a user-defined fitness function for given user-defined operating conditions. The optimization study is subjected to general constraints of weight balance and energy balance. Optimal solutions have been obtained for two different configurations. These are—conventional airship and winged hybrid airship. The solutions have been obtained for four different days of the year, in order to analyse any potential benefits and pitfalls of the two configurations for the varying conditions over the course of one year. The results obtained are generally found to be in excellent agreement with the imposed constraints. The winged hybrid airship configuration was found to have offered no significant benefits in comparison to the conventional configuration. The analysis of the key parameters and data values readily supports this conclusion.

Optimum Vibration Design of Fiber Metal Laminated Panels by Particle Swarm Optimization Algorithm

2011 ◽  
Author(s):  
Mohammad Homayoun Sadr ◽  
Hadi Ghashochi Bargh ◽  
Hoofar Pourzand ◽  
Masoud Karimi
Keyword(s):  
Particle Swarm Optimization ◽  
Plate Theory ◽  
Fitness Function ◽  
Particle Swarm ◽  
Pso Algorithm ◽  
Swarm Optimization ◽  
Good Efficiency ◽  
Design Variables ◽  
Laminated Panels ◽  
Fiber Metal

This paper illustrates the application of the particle swarm optimization (PSO) algorithm to the lay-up design of symmetrically fiber metal laminated panels for maximization of fundamental frequency. The design variables are the number of layers, the fiber orientation angles of inner composite layers, edge conditions and panel length/width ratios. The classical laminated plate theory (CLPT) is used to calculate the natural frequencies and the fitness function is computed with a semi-analytical finite strip method which has been developed on the basis of full energy methods. The performance of the PSO is also compared with the simple genetic algorithm and shows the good efficiency of the PSO algorithm. To check the validity, the results are corroborated by comparing with some other stacking sequences.

scholarly journals Hybrid Seven-bar Press Mechanism

2018 ◽  
Vol 12 (3) ◽  
pp. 181-187
Author(s):  
M. Erkan Kütük ◽  
L. Canan Dülger
Keyword(s):  
Genetic Algorithm ◽  
Objective Function ◽  
Design Optimization ◽  
Hybrid System ◽  
Degrees Of Freedom ◽  
Dimensional Synthesis ◽  
Design Variables ◽  
Optimization Study ◽  
Metal Stamping

An optimization study with kinetostatic analysis is performed on hybrid seven-bar press mechanism. This study is based on previous studies performed on planar hybrid seven-bar linkage. Dimensional synthesis is performed, and optimum link lengths for the mechanism are found. Optimization study is performed by using genetic algorithm (GA). Genetic Algorithm Toolbox is used with Optimization Toolbox in MATLAB®. The design variables and the constraints are used during design optimization. The objective function is determined and eight precision points are used. A seven-bar linkage system with two degrees of freedom is chosen as an example. Metal stamping operation with a dwell is taken as the case study. Having completed optimization, the kinetostatic analysis is performed. All forces on the links and the crank torques are calculated on the hybrid system with the optimized link lengths

The Adoption of Health Promotion Programs by State Agencies

1987 ◽  
Vol 16 (3) ◽  
pp. 235-242 ◽  
Author(s):  
Nell H. Gottlieb ◽  
Linda E. Lloyd ◽  
Jean N. Bounds
Keyword(s):  
Health Promotion ◽  
Diffusion Theory ◽  
General Interest ◽  
State Agencies ◽  
Health Promotion Programs ◽  
Potential Benefits ◽  
Education Act ◽  
One Year ◽  
Time And Energy ◽  
Personnel Directors

Personnel directors of Texas state agencies were surveyed one month prior to and one year following the passage of the 1983 Texas State Employee Health Fitness and Education Act. This legislation allowed the agencies to use available funds and facilities for health promotion programs. Most of the personnel directors were aware of the Act and of the potential benefits of health promotion programs. There was general interest in learning more about health promotion, available community resources, and about the time and energy commitments in developing a program. Most believed they would implement programs in the future. In the year following the passage of the Act, 16 percent of the agencies, covering 30,852 employees, had received approval to begin programs. Size was positively related to plan development and approval. The results are discussed using diffusion theory.

Fully Parametric High-Fidelity CFD Model for the Design Optimisation of the Cyclic Stagger Pattern of a Set of Fan Outlet Guide Vanes

2009 ◽  
Author(s):  
Andrea Milli ◽  
Olivier Bron
Keyword(s):  
Complex Geometry ◽  
Single Point ◽  
Sensitivity Study ◽  
Operating Conditions ◽  
High Fidelity ◽  
Cfd Model ◽  
Design Optimisation ◽  
Guide Vanes ◽  
High Loss ◽  
Design Variables

The present paper deals with the redesign of cyclic variation of a set of fan outlet guide vanes by means of high-fidelity full-annulus CFD. The necessity for the aerodynamic redesign originated from a change to the original project requirement, when the customer requested an increase in specific thrust above the original engine specification. The main objectives of this paper are: 1) make use of 3D CFD simulations to accurately model the flow field and identify high-loss regions; 2) elaborate an effective optimisation strategy using engineering judgement in order to define realistic objectives, constraints and design variables; 3) emphasise the importance of parametric geometry modelling and meshing for automatic design optimisation of complex turbomachinery configurations; 4) illustrate that the combination of advanced optimisation algorithms and aerodynamic expertise can lead to successful optimisations of complex turbomachinery components within practical time and costs constrains. The current design optimisation exercise was carried out using an in-house set of software tools to mesh, resolve, analyse and optimise turbomachinery components by means of Reynolds-averaged Navier-Stokes simulations. The original configuration was analysed using the 3D CFD model and thereafter assessed against experimental data and flow visualisations. The main objective of this phase was to acquire a deep insight of the aerodynamics and the loss mechanisms. This was important to appropriately limit the design scope and to drive the optimisation in the desirable direction with a limited number of design variables. A mesh sensitivity study was performed in order to minimise computational costs. Partially converged CFD solutions with restart and response surface models were used to speed up the optimisation loop. Finally, the single-point optimised circumferential stagger pattern was manually adjusted to increase the robustness of the design at other flight operating conditions. Overall, the optimisation resulted in a major loss reduction and increased operating range. Most important, it provided the project with an alternative and improved design within the time schedule requested and demonstrated that CFD tools can be used effectively not only for the analysis but also to provide new design solutions as a matter of routine even for very complex geometry configurations.

Improvement of the Static and Dynamic Characteristics of Magnetic Head Sliders by Optimum Design

1999 ◽  
Vol 122 (1) ◽  
pp. 280-287 ◽  
Author(s):  
Hiromu Hashimoto ◽  
Yasuhisa Hattori
Keyword(s):  
Objective Function ◽  
Optimum Design ◽  
Amplitude Ratio ◽  
Optimization Technique ◽  
Hard Disk Drives ◽  
Maximum Amplitude ◽  
Disk Surface ◽  
Operating Conditions ◽  
Magnetic Head ◽  
Design Variables

The aim of this paper is to develop a general methodology for the optimum design of magnetic head sliders in improving the spacing characteristics between a slider and disk surface under static and dynamic operating conditions of hard disk drives and to present an application of the methodology to the IBM 3380-type slider design. To generate the optimal design variables, the objective function is defined as the weighted sum of the minimum spacing, the maximum difference in the spacing due to variation of the radial location of the head, and the maximum amplitude ratio of the slider motion. Slider rail width, taper length, taper angle, suspension position, and preload are selected as the design variables. Before the optimization of the head, the effects of these five design variables on the objective function are examined by a parametric study, and then the optimum design variables are determined by applying the hybrid optimization technique, combining the direct search method and successive quadratic programming. From the obtained results, the effectiveness of optimum design on the spacing characteristics of magnetic heads is clarified. [S0742-4787(00)03701-2]

Missile Guidance Algorithm Design Using Particle Swarm Optimization

2013 ◽  
Vol 284-287 ◽  
pp. 2411-2415
Author(s):  
Chien Chun Kung ◽  
Kuei Yi Chen
Keyword(s):  
Objective Function ◽  
Fitness Function ◽  
Equations Of Motion ◽  
Algorithm Design ◽  
Solution Space ◽  
Pso Algorithm ◽  
Local Optimum ◽  
Missile Guidance ◽  
Pursuit Evasion ◽  
Guidance Algorithm

This paper presents a technique to design a PSO guidance algorithm for the nonlinear and dynamic pursuit-evasion optimization problem. In the PSO guidance algorithm, the particle positions of the swarm are initialized randomly within the guidance command solution space. With the particle positions to be guidance commands, we predict and record missiles’ behavior by solving point-mass equations of motion during a defined short-range period. Taking relative distance to be the objective function, the fitness function is then evaluated according to the objective function. As the PSO algorithm proceeds, these guidance commands will migrate to a local optimum until the global optimum is reached. This paper implements the PSO guidance algorithm in two pursuit-evasion scenarios and the simulation results show that the proposed design technique is able to generate a missile guidance law which has satisfied performance in execution time, terminal miss distance, time of interception and robust pursuit capability.

Evaluation of Fuel Preparation Systems for Lean Premixing-Prevaporizing Combustors

1986 ◽  
Vol 108 (2) ◽  
pp. 391-395
Author(s):  
W. J. Dodds ◽  
E. E. Ekstedt
Keyword(s):  
System Design ◽  
Large Scale ◽  
Fuel Injection ◽  
Operating Conditions ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Design Concepts ◽  
Mixture Preparation ◽  
Design Variables ◽  
System Length

A series of tests was conducted to provide data for the design of premixing-prevaporizing fuel-air mixture preparation systems for aircraft gas turbine engine combustors. Fifteen configurations of four different fuel-air mixture preparation system design concepts were evaluated to determine fuel-air mixture uniformity at the system exit over a range of conditions representative of cruise operation for a modern commercial turbofan engine. Operating conditions, including pressure, temperature, fuel-air ratio, and velocity had no clear effect on mixture uniformity in systems which used low-pressure fuel injectors. However, performance of systems using pressure atomizing fuel nozzles and large-scale mixing devices was shown to be sensitive to operating conditions. Variations in system design variables were also evaluated and correlated. Mixture uniformity improved with increased system length, pressure drop, and number of fuel injection points per unit area. A premixing system compatible with the combustor envelope of a typical combustion system and capable of providing mixture nonuniformity (standard deviation/mean) below 15% over a typical range of cruise operating conditions was demonstrated.

EU merger review of the acquisition of non-controlling minority shareholdings: where to now?

2015 ◽  
Vol 13 (2) ◽  
pp. 69-92
Author(s):  
Frank Montag ◽  
Mary Wilks
Keyword(s):  
White Paper ◽  
Merger Control ◽  
Eu Merger Control ◽  
Potential Benefits ◽  
One Year ◽  
Minority Shareholdings ◽  
Minority Interests ◽  
Policy Proposals ◽  
Benefits And Costs ◽  
The Eu

AbstractOn 9 July 2014, the European Commission (the Commission) published its White Paper “Towards more effective EU merger control”, which reviewed the operation of the EU Merger Regulation (EUMR) ten years after the introduction of the substantive test of “significant impediment to substantial competition” (SIEC) and proposed certain specific improvements, including the review of non-controlling minority interests under the EUMR. The 2014 White Paper followed approximately one year of consultation with Member States and interested parties, and was accompanied by a Staff Working Document, which analyses in more detail the considerations underlying the policy proposals in the 2014 White Paper, and an Impact Assessment, which analyses the potential benefits and costs of the various policy options considered.Less than six months after the consultation on the 2014 White Paper closed, Competition Commissioner Margrethe Vestager indicated that the Commission is reconsidering its proposals to allow it to review the acquisition of non-controlling minority shareholdings under the EUMR. This decision has been welcomed by many in the business and legal community as the “targeted transparency system” proposed by the Commission had raised a number of concerns regarding proportionality, legal certainty, cost and administrative burden.Whilst we await the Commission’s next move, this article considers whether non-controlling minority shareholdings should be subject to EU merger control and the extent to which the Commission’s originally envisaged system adequately dealt with the issues it sought to address. This article also proposes a number of principles that the authors suggest should be taken into account when designing a balanced system of merger review for acquisitions of non-controlling minority shareholdings in which the burden of the additional review is proportionate to the goals pursued.

scholarly journals Treatment of industrial used water by UASB+CMBR process to produce industrial grade water for reuse

2018 ◽  
Vol 13 (2) ◽  
pp. 424-430 ◽  
Author(s):  
H. Noguchi ◽  
T. Niwa ◽  
Y. Nakamura ◽  
J. K. Agrawal ◽  
W. S. Ang ◽  
...  
Keyword(s):  
Ceramic Membrane ◽  
Operating Conditions ◽  
Anaerobic Sludge ◽  
Stable Operation ◽  
High Quality ◽  
Joint Project ◽  
Industrial Grade ◽  
One Year ◽  
Anaerobic Sludge Blanket

Abstract Joint project has been conducted in a demonstration plant with 1-MGD capacity at Jurong Water Reclamation Plant to produce high quality effluent through a combined process of up-flow anaerobic sludge blanket reactor and ceramic membrane bioreactor (UASB-CMBR). Water quality of the product and energy consumption met target which were evaluated after one-year operation. The joint project has further been conducted to optimize operating conditions including cleaning procedure. Recovery cleaning (RC) of the ceramic membrane was carried out after 18 months operation and permeability was recovered to be initial value. Stable filtration at 25 LMH was achieved after the RC. RO filtration test was also carried out to treat effluent from the UASB-CMBR. Stable operation in the RO system was achieved with flux of 15 LMH and recovery of 60%. Quality of RO permeates met criteria for industrial water. It is concluded that UASB-CMBR process with RO system can produce high quality water for reuse from industrial used water.

scholarly journals The Management of Infants for Cardiac Surgery under Deep Hypothermia

1972 ◽  
Vol 1 (2) ◽  
pp. 137-140 ◽  
Author(s):  
T. C. K. Brown ◽  
C. P. Clarke ◽  
E. A. Shanahan ◽  
B. D. McKie ◽  
H. M. Wood ◽  
...  
Keyword(s):  
Oxygen Supply ◽  
Heart Surgery ◽  
Open Heart Surgery ◽  
Deep Hypothermia ◽  
Operating Conditions ◽  
Temperature Gradients ◽  
Cerebral Oxygen ◽  
Physiological Effects ◽  
Surface Cooling ◽  
One Year

Deep hypothermia is now employed for open heart surgery in infants. The method of surface cooling infants to 25° C and then by-pass cooling down to 15–20° C prior to exsanguination is described. This provides a still heart and ideal operating conditions. The infants are re-warmed on by-pass. Some of the physiological effects of hypothermia and the methods employed to counteract these are discussed. The aims are to reduce temperature gradients, improve cerebral oxygen supply, avoid arrhythmias and secure haemostasis. The experience in 33 operations is outlined. Seventeen patients were under one year of age.

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