scholarly journals Optimization of a ducted fan propulsion system for a single engine aircraft

2021 ◽  
Author(s):  
Adam Jasudavisius
Keyword(s):  
Line Search ◽  
Design Space ◽  
Propulsion System ◽  
Optimization Approach ◽  
Control Points ◽  
Ducted Fan ◽  
Optimization Methodology ◽  
High Degree ◽  
Cruise Flight ◽  
Initial Geometry

The objective of this study was to perform a 3D aerodynamic shape optimization on a ducted fan propulsion system configured for cruise flight on an aircraft. The initial shapes of the duct and hub were determined using a basic grid searching optimization approach. An efficient optimization algorithm was created that utilized the BFGS searching technique with a QuasiNewton line search to refine the initial geometry. The ducted fan was chosen to be controlled by 13 control points connected using a combination of splines, ellipses and conics. The optimum design resulted in a 33.54% and 36.45% reduction in drag for the duct and hub respectively. The propeller thrust was also increased by 141.49%. The optimization methodology used throughout this study proved to be an efficient technique in finding the optimal design to within a high degree of resolution based on the entire design space considered.

scholarly journals Optimization of a ducted fan propulsion system for a single engine aircraft

2021 ◽  
Author(s):  
Adam Jasudavisius
Keyword(s):  
Line Search ◽  
Design Space ◽  
Propulsion System ◽  
Optimization Approach ◽  
Control Points ◽  
Ducted Fan ◽  
Optimization Methodology ◽  
High Degree ◽  
Cruise Flight ◽  
Initial Geometry

The objective of this study was to perform a 3D aerodynamic shape optimization on a ducted fan propulsion system configured for cruise flight on an aircraft. The initial shapes of the duct and hub were determined using a basic grid searching optimization approach. An efficient optimization algorithm was created that utilized the BFGS searching technique with a QuasiNewton line search to refine the initial geometry. The ducted fan was chosen to be controlled by 13 control points connected using a combination of splines, ellipses and conics. The optimum design resulted in a 33.54% and 36.45% reduction in drag for the duct and hub respectively. The propeller thrust was also increased by 141.49%. The optimization methodology used throughout this study proved to be an efficient technique in finding the optimal design to within a high degree of resolution based on the entire design space considered.

scholarly journals A new stress-based topology optimization approach for finding flexible structures

2021 ◽  
Author(s):  
Martin Noack ◽  
Arnold Kühhorn ◽  
Markus Kober ◽  
Matthias Firl
Keyword(s):  
Topology Optimization ◽  
Stress State ◽  
Design Space ◽  
Flexible Structures ◽  
Optimization Approach ◽  
Principal Stresses ◽  
Output Displacement ◽  
Design Concepts ◽  
Flexible Designs ◽  
Gauss Points

AbstractThis paper presents a new FE-based stress-related topology optimization approach for finding bending governed flexible designs. Thereby, the knowledge about an output displacement or force as well as the detailed mounting position is not necessary for the application. The newly developed objective function makes use of the varying stress distribution in the cross section of flexible structures. Hence, each element of the design space must be evaluated with respect to its stress state. Therefore, the method prefers elements experiencing a bending or shear load over elements which are mainly subjected to membrane stresses. In order to determine the stress state of the elements, we use the principal stresses at the Gauss points. For demonstrating the feasibility of the new topology optimization approach, three academic examples are presented and discussed. As a result, the developed sensitivity-based algorithm is able to find usable flexible design concepts with a nearly discrete 0 − 1 density distribution for these examples.

scholarly journals Optimal design of Vertical-Taking-Off-and-Landing UAV wing using multilevel approach

2020 ◽  
Vol 11 ◽  
pp. 26
Author(s):  
Hao Yue ◽  
David Bassir ◽  
Hicham Medromi ◽  
Hua Ding ◽  
Khaoula Abouzaid
Keyword(s):  
Optimization Problem ◽  
Delta Wing ◽  
Optimization Approach ◽  
Multilevel Optimization ◽  
Distribution Strategy ◽  
Surface Method ◽  
Flight Mode ◽  
Aerial Vehicle ◽  
Computational Fluid Dynamics Cfd ◽  
Cruise Flight

In order to overcome the propre disadvantages of FW(Fixed-Wing) and VTOL(Vertical-Taking-Off-and-Landing) UAV (Unmanned Aerial Vehicle) and extend its application, the hybrid drone is invested more in recent years by researchers and several classifications are developed on the part of dual system. In this article, an innovative hybrid UAV is raised and studied by introducing the canard configuration that is coupled with conventional delta wing as well as winglet structure. Profited by Computational Fluid Dynamics (CFD) and Response Surface Method (RSM), a multilevel optimization approach is practically presented and concerned in terms of cruise flight mode: adopted by an experienced-based distribution strategy, the total lift object is respectively assigned into the delta wing (90–95%) and canard wing(5–10%) which is applied into a two-step optimization: the first optimization problem is solved only with the parameters concerned with delta wing afterwards the second optimization is successively concluded to develop the canard configuration considering the optimized delta wing conception. Above all, the optimal conceptual design of the delta and canard wing is realized by achieving the lift goal with less drag performance in cruise mode.

scholarly journals Multistable Morphing Mechanisms of Nonlinear Springs

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Chrysoula Aza ◽  
Alberto Pirrera ◽  
Mark Schenk
Keyword(s):  
Design Space ◽  
Large Deformations ◽  
Compliant Mechanisms ◽  
Helical Structures ◽  
Nonlinear Springs ◽  
Structural Assembly ◽  
Stiffness Characteristics ◽  
Nonlinear Components ◽  
Type Of Behavior ◽  
Initial Geometry

Compliant mechanisms find use in numerous applications in both microscale and macroscale devices. Most of the current compliant mechanisms base their behavior on beam flexures. Their range of motion is thus limited by the stresses developed upon deflection. Conversely, the proposed mechanism relies on elastically nonlinear components to achieve large deformations. These nonlinear elements are composite morphing double-helical structures that are able to extend and coil like springs, yet, with nonlinear stiffness characteristics. A mechanism consisting of such structures, assembled in a simple truss configuration, is explored. A variety of behaviors is unveiled that could be exploited to expand the design space of current compliant mechanisms. The type of behavior is found to depend on the initial geometry of the structural assembly, the lay-up, and other characteristics specific of the composite components.

Design, Fabrication and Analysis of an Electric Ducted Fan

2019 ◽  
Author(s):  
Parthasarathy Vasanthakumar ◽  
Jigme Tsering ◽  
Sumanth Siddhartha Suddunuri
Keyword(s):  
Rapid Development ◽  
Propulsion System ◽  
Basic Principles ◽  
Blade Element Theory ◽  
Ducted Fan ◽  
Ansys Cfx ◽  
Electric Aircraft ◽  
Feasible Option ◽  
Efficient Combustion ◽  
Battery Technology

Abstract Driven by rapid development in battery technology and increase in scope for electric air taxi vehicles, developing an efficient combustion free propulsion system to pair with an electric aircraft is crucial for future of aircraft industry. However, with current technology, ducted fan configuration engines are the only feasible option when it comes to combustion free propulsion system which are already being used in many unmanned drones and unmanned aerial vehicles. In the present work, simple design, analysis and fabrication of ducted fan is performed. Propeller fan and duct is designed using basic principles of blade element theory and momentum theory. Using the parameters from the theoretical design phase, 3D model is made and fabricated using 3D printing and assembled to fit with tolerances suitable for mounting motor. A test stand capable of measuring thrust by varying rpm is designed and built using Arduino based interface. Finally, the designed model is analyzed in Ansys CFX for thrust output using an MRF simulation.

Optimization Methodology for Composite Stiffened Panel Based on Genetic Algorithm

2014 ◽  
Vol 952 ◽  
pp. 34-37
Author(s):  
Da Feng Jin ◽  
Zhe Liu ◽  
Zhi Rui Fan
Keyword(s):  
Genetic Algorithm ◽  
Finite Element Method ◽  
Finite Element ◽  
Design Space ◽  
Design Guidelines ◽  
Stiffened Panel ◽  
Stacking Sequence ◽  
Design Variables ◽  
Composite Stiffened Panel ◽  
Optimization Methodology

A novel optimization methodology for stiffened panel is proposed in this paper. The purpose of the optimization methodology is to improve the first buckling load of the panel which is obtained by finite element method. The stacking sequence of the stiffeners is taken as design variables. In order to ensure the manufacturability of design, the design guidelines of stacking sequence are taken into account. A DOE based on Halton Sequence makes the initial points of genetic algorithm spread more evenly in the design space of laminate parameters and consequently accelerates the search to convergence. The numerical example verifies the efficiency of this method.

Material Optimization for Design Improvement of Crash Energy Absorbers

2010 ◽  
Author(s):  
Hesham Ibrahim
Keyword(s):  
Impact Energy ◽  
Design Space ◽  
Thickness Distribution ◽  
Optimization Approach ◽  
Optimum Thickness ◽  
Energy Absorber ◽  
Design Improvement ◽  
Material Type ◽  
Thin Walled ◽  
Energy Absorbers

Crash energy absorbers in the form of thin walled tubes play a significant role in mitigating the harmful effects of frontal vehicles accidents on occupants. Specific energy absorbed (SEA), which is the ratio of impact energy absorbed to mass, is usually used to evaluate the efficiency of crash energy absorbers. A good design of a crash energy absorber must maximize the amount of impact energy that can be absorbed with a certain weight. The formal approach that has been used to improve the design of crash energy absorbers is to employ optimization to search for the optimum thickness distribution that maximizes SEA. This approach can be conceptualized as searching the design space in only one dimension (thickness). In this paper, a new dimension is added to the design space (material type). The proposed approach considers the type of material as a variable. An optimum design is then found by not only searching for the optimum thickness distribution, but also by selecting the optimum material type. The approach is demonstrated to the design improvement of a crash energy absorber in the form of a thin walled tube of square cross section. Steel and magnesium have been used as the two material alternatives. Magnesium has been selected due to its low density that had made it a promising candidate for use as a structural material in the automobile manufacturing. The results have shown that following the proposed technique, SEA has been increased by 54% compared to the value obtained through following the formal design optimization approach.

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