Integrated Aerodynamic and Geometric Modeling for Hypersonic Vehicle Design

2000 ◽  
Author(s):  
Amarshi A. Bhungalia ◽  
Jeffrey V. Zweber ◽  
Mark D. Stevenson
Keyword(s):  
Wind Tunnel ◽  
Design Process ◽  
Geometric Modeling ◽  
High Speed ◽  
Vehicle Design ◽  
Viscous Effects ◽  
Aerodynamic Analysis ◽  
Hypersonic Aircraft ◽  
Arbitrary Body ◽  
Analysis System

Abstract In the past, hypersonic aircraft and space launch vehicle designs were dependent on empirical methods that were developed and verified using wind tunnel testing. This process was time consuming and extremely expensive. The vehicle designers were forced to look for improved ways to assess the design because they needed to cut the design costs. This led to the development of high-speed aerodynamic analysis codes. These codes cut the design costs by reducing the number of wind tunnel tests that were required (and eliminating the associated time and expense). Currently, there are many different aerodynamic analysis codes, of different fidelities, available for use in the design process. One of these codes is the Supersonic/Hypersonic Arbitrary Body Program (S/HABP). Versions of S/HABP are implemented with varying pre and post-processing applications. Two of the common ones are the Aerodynamic Preliminary Analysis System (APAS) and Viscous Effects on Complex Configurations (VECC). Both APAS and VECC are stand-alone specialized codes that are not well integrated into the design process. This paper documents an application that was developed to improve the process of generating an aerodynamic analysis mesh for S/HABP from the geometric modeling activities that are needed for the overall vehicle design process.

Development of variable camber wing with morphing leading and trailing sections using corrugated structures

2016 ◽  
Vol 27 (20) ◽  
pp. 2827-2836 ◽  
Author(s):  
Hiroki Takahashi ◽  
Tomohiro Yokozeki ◽  
Yoshiyasu Hirano
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Wind Tunnel ◽  
Design Process ◽  
Leading Edge ◽  
Wind Tunnel Experiment ◽  
Prototype Model ◽  
Morphing Wing ◽  
Trailing Edge ◽  
Aerodynamic Analysis

This article describes the development of variable camber morphing wing, which is mainly composed of corrugated structures. The morphing wing with both leading edge and trailing edge morphing sections is proposed and the prototype model is designed by consideration of finite element structural analysis with actuation mechanisms and aerodynamic analysis. Through wind tunnel experiment with the manufactured prototype model, smooth actuation without harmful deformation under 20 m/s airflow is demonstrated. The observed deformation shape is well correlated with simulated shape by analysis. Thereby, the feasibility of the present morphing wing mechanism and design process are verified.

Downward pointing winglet design and assessment within the M-DAW research project

2009 ◽  
Vol 113 (1142) ◽  
pp. 221-232 ◽  
Author(s):  
J.-L. Hantrais-Gervois ◽  
R. Grenon ◽  
A. Mann ◽  
A. Büscher
Keyword(s):  
Performance Analysis ◽  
Wind Tunnel ◽  
Design Process ◽  
High Speed ◽  
Bending Moment ◽  
Navier Stokes ◽  
Structural Modifications ◽  
And Performance ◽  
Wing Tip ◽  
Transonic Wind Tunnel

AbstractThe design and performance analysis of a wing tip device proposed within the M-DAW project by ONERA is presented. A proto-design process is described and the device was thoroughly assessed (mainly with Reynolds-Averaged Navier-Stokes simulations). The process was further explained through wind-tunnel tests at both low speed and high speed in the pressurised and cryogenic European transonic wind tunnel in Cologne. The device is a downward pointing winglet designed for a retrofit scenario (the wing could be modified only within the 96% – 100% bounds of the span). It was designed to keep the wing root bending moment of the clean wing at cruise unchanged so that the aerodynamic gains are the net gains provided by the device that can be directly installed without structural modifications of the wing.

scholarly journals Optimization of Air Gap Length and Capacitive Auxiliary Winding in Three-Phase Induction Motors Based on a Genetic Algorithm

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4407
Author(s):  
Mbika Muteba
Keyword(s):  
Genetic Algorithm ◽  
Design Process ◽  
Power Factor ◽  
High Speed ◽  
High Efficiency ◽  
Air Gap ◽  
Element Analysis ◽  
Three Phase ◽  
High Torque ◽  
Cage Induction Motor

There is a necessity to design a three-phase squirrel cage induction motor (SCIM) for high-speed applications with a larger air gap length in order to limit the distortion of air gap flux density, the thermal expansion of stator and rotor teeth, centrifugal forces, and the magnetic pull. To that effect, a larger air gap length lowers the power factor, efficiency, and torque density of a three-phase SCIM. This should inform motor design engineers to take special care during the design process of a three-phase SCIM by selecting an air gap length that will provide optimal performance. This paper presents an approach that would assist with the selection of an optimal air gap length (OAL) and optimal capacitive auxiliary stator winding (OCASW) configuration for a high torque per ampere (TPA) three-phase SCIM. A genetic algorithm (GA) assisted by finite element analysis (FEA) is used in the design process to determine the OAL and OCASW required to obtain a high torque per ampere without compromising the merit of achieving an excellent power factor and high efficiency for a three-phase SCIM. The performance of the optimized three-phase SCIM is compared to unoptimized machines. The results obtained from FEA are validated through experimental measurements. Owing to the penalty functions related to the value of objective and constraint functions introduced in the genetic algorithm model, both the FEA and experimental results provide evidence that an enhanced torque per ampere three-phase SCIM can be realized for a large OAL and OCASW with high efficiency and an excellent power factor in different working conditions.

scholarly journals The Optimization of Alternating Current Electrospun PA 6 Solutions Using a Visual Analysis System

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2098
Author(s):  
Tomas Kalous ◽  
Pavel Holec ◽  
Jakub Erben ◽  
Martin Bilek ◽  
Ondrej Batka ◽  
...  
Keyword(s):  
High Voltage ◽  
High Speed ◽  
Visual Analysis ◽  
Polyamide 6 ◽  
Alternating Current ◽  
Sine Wave ◽  
Electrospinning Process ◽  
Camera System ◽  
Polymeric Solutions ◽  
Analysis System

The electrospinning process that produces fine nanofibrous materials have a major disadvantage in the area of productivity. However, alternating current (AC) electrospinning might help to solve the problem via the modification of high voltage signal. The aforementioned productivity aspect can be observed via a camera system that focuses on the jet creation area and that measures the average lifespan. The paper describes the optimization of polyamide 6 (PA 6) solutions and demonstrates the change in the behavior of the process following the addition of a minor dose of oxoacid. This addition served to convert the previously unspinnable (using AC) solution to a high-quality electrospinning solution. The visual analysis of the AC electrospinning of polymeric solutions using a high-speed camera and a programmable power source was chosen as the method for the evaluation of the quality of the process. The solutions were exposed to high voltage applying two types of AC signal, i.e., the sine wave and the step change. All the recordings presented in the paper contained two sets of data: firstly, camera recordings that showed the visual expression of electrospinning and, secondly, signal recordings that provided information on the data position in the signal function.

Numerical Simulation of Flowfield around High Speed Trains Passing by each other at the same Speed

2011 ◽  
Vol 97-98 ◽  
pp. 698-701
Author(s):  
Ming Lu Zhang ◽  
Yi Ren Yang ◽  
Li Lu ◽  
Chen Guang Fan
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Flow Field ◽  
Point Source ◽  
High Speed ◽  
Stokes Equations ◽  
Field Structure ◽  
Vehicle Speed ◽  
Mesh Method ◽  
High Speed Trains

Large eddy simulation (LES) was made to solve the flow around two simplified CRH2 high speed trains passing by each other at the same speed base on the finite volume method and dynamic layering mesh method and three dimensional incompressible Navier-Stokes equations. Wind tunnel experimental method of resting train with relative flowing air and dynamic mesh method of moving train were compared. The results of numerical simulation show that the flow field structure around train is completely different between wind tunnel experiment and factual running. Two opposite moving couple of point source and point sink constitute the whole flow field structure during the high speed trains passing by each other. All of streamlines originate from point source (nose) and finish with the closer point sink (tail). The flow field structure around train is similar with different vehicle speed.

Design for Assembly Evaluation of Orientation Difficulty Features

1992 ◽  
Author(s):  
Robert H. Sturges ◽  
Jui-Te Yang
Keyword(s):  
Geometric Modeling ◽  
Boundary Representation ◽  
Design For Assembly ◽  
Assembly Process ◽  
Assembly Evaluation ◽  
Index Of Difficulty ◽  
Analysis System ◽  
Time Required ◽  
High Level ◽  
Geometric Modeling System

Abstract In support of the effort to bring downstream issues to the attention of the designer as parts take shape, an analysis system is being built to extract certain features relevant to the assembly process, such as the dimension, shape, and symmetry of an object. These features can be applied to a model during the downstream process to evaluate handling and assemblability. In this paper, we will focus on the acquisition phase of the assembly process and employ a Design for Assembly (DFA) evaluation to quantify factors in this process. The capabilities of a non-homogeneous, non-manifold boundary representation geometric modeling system are used with an Index of Difficulty (ID) that represents the dexterity and time required to assemble a product. A series of algorithms based on the high-level abstractions of loop and link are developed to extract features that are difficult to orient, which is one of the DFA criteria. Examples for testing the robustness of the algorithms are given. Problems related to nearly symmetric outlines are also discussed.

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