scholarly journals Aerodynamic Characterization of Hypersonic Transportation Systems and Its Impact on Mission Analysis

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3580
Author(s):  
Nicole Viola ◽  
Pietro Roncioni ◽  
Oscar Gori ◽  
Roberta Fusaro
Keyword(s):  
Flight Control ◽  
Transportation Systems ◽  
Design Stage ◽  
Propulsion Systems ◽  
Mission Analysis ◽  
Aerodynamic Model ◽  
Preliminary Design Stage ◽  
Comparison Of The Results ◽  
Control Surfaces

This paper aims to provide technical insights on the aerodynamic characterization activities performed in the field of the H2020 STRATOFLY project, for the Mach 8 waverider reference configuration. Considering the complexity of the configuration to be analyzed at conceptual/preliminary design stage, a build-up approach has been adopted. The complexity of the aerodynamic model increases incrementally, from the clean external configuration up to the complete configuration, including propulsion systems elements and flight control surfaces. At each step, the aerodynamic analysis is complemented with detailed mission analysis, in which the different versions of the aerodynamic databases are used as input for the trajectory simulation. eventually, once the contribution to the aerodynamic characterization of flight control surfaces is evaluated, stability and trim analysis is carried out. The comparison of the results obtained through the different mission analysis campaigns clearly shows that the accuracy of aerodynamic characterization may determine the feasibility or unfeasibility of a mission concept.

The Development of a Closed-Loop Flight Controller for Localized Flow Control and Gust Alleviation Using Biomimetic Feathers on Aircraft Wings

2011 ◽  
Author(s):  
Christopher J. Blower ◽  
Adam M. Wickenheiser
Keyword(s):  
Flow Control ◽  
Flight Control ◽  
Trailing Edge ◽  
Control Loops ◽  
Aircraft Wings ◽  
Trailing Edge Flaps ◽  
Wing Structure ◽  
Inertial Measurements ◽  
Control Surfaces

On avian wings, significant flow control is accomplished using localized control loops, both active and passive, between leading- and trailing-edge feathers. Conversely, most man-made flight control systems respond to perturbations in inertial measurements (global states) rather than the flow itself (local states). This paper presents the design of a distributed, biomimetic flow control system and a characterization of its performance compared to a wing with traditional control surfaces relying on inertial measurements. This new design consists of a skeletal wing structure with a network of feather-like panels installed on the upper and lower surfaces, extending beyond the trailing edge and replacing leading- and trailing-edge flaps/ailerons. Each feather is able to deform into and out of the boundary layer, thus permitting local airflow manipulation and transpiration through the wing. For this study, two airfoil sections are compared — a standard wing section with a trailing-edge flap, and section with multiple trailing-edge feathers. COMSOL Multiphysics is used to model the flow field under various flight conditions and flap deflections. A dynamics model of the wing is also simulated in order to compute the disturbances caused by wind gusts. Continuous gusts are simulated, and the disturbance rejection capabilities of the baseline and feathered wing cases are compared.

scholarly journals On computing dynamic loads on flight control surfaces subjected to impact

2018 ◽  
pp. 51-58
Author(s):  
E. A. Samokhina ◽  
P. A. Samokhin
Keyword(s):  
Finite Element ◽  
Flight Control ◽  
Software Package ◽  
Dynamic Loads ◽  
Design Stage ◽  
Natural Vibrations ◽  
Finite Element Software ◽  
Initial Design ◽  
Control Surfaces ◽  
Structure Properties

Predicting structure properties at the initial design stage is especially important for products that will undergo vibration and impact when used. The paper presents a technique for computing dynamic loads on an aircraft rudder arm when it strikes an arrester as it unfolds in flight. We used a finite element software package to analyse the natural vibrations of the structure.

Numerical evaluation of hydrodynamic characteristics of planing hulls by using a hybrid method

2021 ◽  
pp. 147509022199024
Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Design Stage ◽  
Hydrodynamic Characteristics ◽  
Calm Water ◽  
Preliminary Design Stage ◽  
Reduction Function ◽  
Hull Forms ◽  
Good Agreement

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.

scholarly journals Uniform deformation design of outrigger braced skyscrapers: A simplified method for the preliminary design stage

Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 395-405
Author(s):  
Arsalan Alavi ◽  
Elena Mele ◽  
Reza Rahgozar ◽  
Ehsan Noroozinejad Farsangi ◽  
Izuru Takewaki ◽  
...  
Keyword(s):  
Design Stage ◽  
Preliminary Design ◽  
Uniform Deformation ◽  
Simplified Method ◽  
Preliminary Design Stage

scholarly journals Critical Review of EMC Standards for the Measurement of Radiated Electromagnetic Emissions from Transit Line and Rolling Stock

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 759
Author(s):  
Andrea Mariscotti
Keyword(s):  
Time Distribution ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Transportation Systems ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Intrinsic Variability ◽  
Statistical Characterization ◽  
Electromagnetic Emissions

Accurate and comprehensive methods for the assessment of radiated electromagnetic emissions in modern electric transportation systems are a necessity. The characteristics and susceptibility of modern victim signaling and communication radio services, operating within and outside the right-of-way, require an update of the measurement methods integrating or replacing the swept frequency technique with time domain approaches. Applicable standards are the EN 50121 (equivalent to the IEC 62236) and Urban Mass Transport Association (UMTA) with additional specifications from project contracts. This work discusses the standardized methods and settings, and the representative operating conditions, highlighting areas where improvements are possible and opportune (statistical characterization of measurement results, identification and distinction of emissions and line resonances, and narrowband and broadband phenomena). In particular for the Electromagnetic Compatibility (EMC) assessment with new Digital Communication Systems, the characterization of time distribution of spectral properties is discussed, e.g., by means of Amplitude Probability Distribution and including time distribution information. The problem of determination of site and setup uncertainty and repeatability is also discussed, observing on one hand the lack of clear indications in standards and, on the other hand, the non-ideality and intrinsic variability of measurement conditions (e.g., rolling stock operating conditions, synchronization issues, and electric arc intermittence).

Concurrent Engineering Design of Sheet Stamping by Using an Inverse FE Approach

1997 ◽  
Author(s):  
Shiyong Yang ◽  
Kikuo Nezu
Keyword(s):  
Finite Element ◽  
Concurrent Engineering ◽  
Process Simulation ◽  
Three Dimensional ◽  
Sheet Forming ◽  
Design Stage ◽  
Forming Process ◽  
Element Analysis ◽  
Preliminary Design Stage ◽  
Product And Process

Abstract An inverse finite element (FE) algorithm is proposed for sheet forming process simulation. With the inverse finite element analysis (FEA) program developed, a new method for concurrent engineering (CE) design for sheet metal forming product and process is proposed. After the product geometry is defined by using parametric patches, the input models for process simulation can be created without the necessity to define the initial blank and the geometry of tools, thus simplifying the design process and facilitating the designer to look into the formability and quality of the product being designed at preliminary design stage. With resort to a commercially available software, P3/PATRAN, arbitrarily three-dimensional product can be designed for manufacturability for sheet forming process by following the procedures given.

An Approximate Method for Intact Stability of Fishing Vessels

1999 ◽  
Vol 36 (03) ◽  
pp. 171-174
Author(s):  
Hüseyin Yilmaz ◽  
Abdi Kükner
Keyword(s):  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Ship Stability ◽  
Fishing Vessels ◽  
Initial Stability ◽  
Intact Stability ◽  
Preliminary Design Stage ◽  
Reduce Risk ◽  
Vessel Stability

It is well known that stability is the most important safety requirement for ships. One should have some information on ship stability at the preliminary design stage in order to reduce risk. Initial stability of ships is an important criterion and can be closely evaluated in terms of form parameters and vertical center of gravity. In this study, using some sample ship data, approximate formulations are derived by means of regression analysis for the calculations expressed in terms of ship preliminary design parameters that can easily provide approximate GM calculations. Thus designers can be provided with ship stability at the preliminary design stage, and also a set of appropriate design parameters for improving vessel stability can easily be determined.

Comparison of Numerical Methods for Determining Torsion Stiffness of Automotive Chassis

2011 ◽  
Author(s):  
Steven Tebby ◽  
Ebrahim Esmailzadeh ◽  
Ahmad Barari
Keyword(s):  
Finite Element Analysis ◽  
Analytical Approach ◽  
Torsional Stiffness ◽  
Design Stage ◽  
Element Analysis ◽  
Detailed Design ◽  
Vertical Displacements ◽  
Comparison Of The Results ◽  
Torsion Stiffness

The torsion stiffness of an automotive chassis can be determined using an analytical approach based purely on geometry, using an experimental method, or alternatively by employing a Finite Element Analysis (FEA) process. These three methods are suitable at different design stages and combined together could prove to be practical methods of determining the torsion stiffness of a chassis. This paper describes and compares two distinct FEA processes to determine the torsion stiffness of an automotive chassis during the detailed design stage. The first process iteratively applies forces to the model and records displacements, while the second process gradually applies vertical displacements in place of force to determine the torsional stiffness threshold. Each method is explained and supported with a case study to provide a basis of comparison of the results.

Research on the ELAC Systems of A320 Family Aircrafts

2012 ◽  
Vol 546-547 ◽  
pp. 1562-1567
Author(s):  
Kai Yin ◽  
Gang Yin ◽  
Qin Zhen Li
Keyword(s):  
Computer System ◽  
Basic Principle ◽  
Flight Control ◽  
On Line ◽  
Control Surfaces ◽  
Driving Circuit

This document introduces the basic principle of the ELAC System (Elevator Aileron Computer System) working of A320 aircrafts, and mainly, analyzes the driving circuit of the ELAC computer for the flight control surfaces. Furthermore, introduces a real fault on line maintenance, analyze it and find out the reason, give some useful advice on A320 aircraft line maintenance.

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