Mathematical Modelling for Wave Drag Optimization and Design of High-Speed Aircrafts

2017 ◽  
pp. 109-132
Author(s):  
Can Citak ◽  
Serkan Ozgen ◽  
Gerhard Wilhelm Weber
Keyword(s):  
Mathematical Modelling ◽  
High Speed ◽  
Wave Drag

Supersonic Bi-Directional Flying Wing Wave Drag Optimization Based on Alternative Form of CST Method

2013 ◽  
Vol 477-478 ◽  
pp. 240-245
Author(s):  
Xiaohui Guan
Keyword(s):  
Drag Reduction ◽  
High Speed ◽  
Wave Drag ◽  
Alternative Form ◽  
Shape Transformation ◽  
Flat Bottom ◽  
Symmetric Configuration ◽  
Shape Parameterization ◽  
Wave Drag Reduction ◽  
Sufficient Precision

Bi-directional Flying Wing (BFW) is a new supersonic civil transport shape concept that aims to meet the conflict requirements of high speed cruise and low speed take-off/landing missions. In this paper the Class-Shape-Transformation (CST) shape parameterization method is modified to represent the BFW shape, and new basis functions suitable for the BFW airfoil representation are constructed. The Far-field Composite Element (FCE) wave drag optimization is performed on both the flat bottom and symmetric BFW configurations, and the drag reduction effects and result precision are surveyed. It is suggested that significant wave drag reduction can be achieved by the FCE optimization for both the flat bottom and the symmetric BFW configurations. The wave drag coefficients with sufficient precision can be obtained in the FCE optimization of the symmetric configuration; while the FCE optimization results of the flat bottom one are not accurate enough.

scholarly journals Brief Review and Mathematical Modelling of Air Cushioned Pressurized Paper Machine Headbox

2018 ◽  
Vol 7 (3.4) ◽  
pp. 57 ◽  
Author(s):  
Parvesh Saini ◽  
Rajesh Kumar
Keyword(s):  
Mathematical Modelling ◽  
High Speed ◽  
Paper Industry ◽  
Paper Machine ◽  
Efficient Operation ◽  
Precise Control ◽  
Paper Machines ◽  
Day By Day ◽  
Paper Machine Headbox

Today, the requirement of high grade papers is increasing day by day. To cater the need of high quality papers, new high-speed paper machines are being developed constantly. The whole economy of a pulp and paper industry depends on the quality of paper produced, quality of paper depends on the efficient operation of the major part of paper industry – paper machine. Paper machine is the heart of paper industry and has many subsystems. One of the important subsystem of paper machine is Headbox.   To have the desired quality papers, efficient working of headbox is highly required. To have desired operation from headbox, its precise control is necessary. The precise modelling of headbox, leads to design of efficient controllers for its proper control to get the desired response. This paper presents the mathematical modelling of headbox along with a brief review of various research performed on headbox.  

A hybrid beam element for mathematical modelling of high-speed flexible linkages

1989 ◽  
Vol 24 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Xiaochun Gao ◽  
Zhiying King ◽  
Qixian Zhang
Keyword(s):  
Mathematical Modelling ◽  
High Speed ◽  
Beam Element ◽  
Hybrid Beam

Mathematical Modelling of Reed Valve Behaviour in High Speed Two-Stroke Engines

1997 ◽  
Author(s):  
Robert Fleck ◽  
Anthony Cartwright ◽  
David Thornhill
Keyword(s):  
Mathematical Modelling ◽  
High Speed ◽  
Reed Valve

scholarly journals Effects of Heat Addition on Wave Drag Reduction of a Spiked Blunt Body

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hongyu Wang ◽  
Yanguang Yang ◽  
Langquan Li ◽  
Gang Wang ◽  
Qinghu Zhang
Keyword(s):  
Drag Reduction ◽  
High Speed ◽  
Blunt Body ◽  
Wave Drag ◽  
The Body ◽  
Continuous Heating ◽  
Heat Addition ◽  
Reduction Coefficient ◽  
Wave Drag Reduction ◽  
High Speed Vehicle

Drag reduction technology plays a significant role in extending the flight range for a high-speed vehicle. A wave drag reduction strategy via heat addition to a blunt body with a spike was proposed and numerically validated. The heat addition is simulated with continuous heating in a confined area upstream of the blunt body. The effects of heat addition on drag reduction in three flow conditions ( M = 3.98 , 5 , 6 ) were compared, and the influence of power density q h ( q 1 = 2.0 × 10 8   W / m 3 , q 2 = 5.0 × 10 8   W / m 3 , and q 3 = 1.0 × 10 9   W / m 3 ) of heating was evaluated. Results show that the heat addition has a positive way to reduce the drag of the body with a spike alone, and more satisfactory drag reduction effectiveness can be achieved at a higher Mach number. The drag reduction coefficient increases with q h in the same flow condition, with a maximum of 38.9% ( M = 6 ) as q 3 = 1.0 × 10 9   W / m 3 . The wave drag reduction principle was discussed by a transient calculation, which indicates that the separation region has entrainment of the heated air and expanded with its sonic line away from the blunt cone, which results in an alleviation of the pressure load caused by shock/shock interaction.

scholarly journals Mathematical Modelling and Analysis of Memristors with and without its Temperature Effects

2017 ◽  
Vol 63 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Bhavani Prasad ◽  
Kamaraju Maddu ◽  
Venkata Lakshmi
Keyword(s):  
Mathematical Modelling ◽  
Temperature Effects ◽  
High Speed ◽  
Ionic Mobility ◽  
Complete Analysis ◽  
Matlab Simulink ◽  
The Relationship

Abstract In this paper the main goal is to study the principle structure and characteristics of single and multiple memristors and also the temperature effects. The complete analysis described here is done by using matlab Simulink. The relationship between the on resistance, off resistance and ionic mobility with respect to temperature has been analyzed and shown graphically. The memristor can be used as a High speed switch and it can be used in non volatile computer memories due to its higher switching speeds.

Drag Reduction Performance due to Repetitive Laser Pulses on the Blunt Body

2011 ◽  
Author(s):  
Jae-Hyung Kim ◽  
Akihiro Sasoh
Keyword(s):  
Drag Reduction ◽  
High Speed ◽  
Energy Deposition ◽  
Blunt Body ◽  
Laser Pulses ◽  
Wave Drag ◽  
Force Balance ◽  
Balance System ◽  
Convex Lens ◽  
Wave Drag Reduction

Supersonic wave drag reduction due to the repetitive laser induced energy deposition is performed experimentally in this study. Laser pulses are irradiated through a convex lens installed in side of the in-draft wind tunnel of Mach 1.94. The maximum frequency and power of the energy deposition is limited up to 50kHz and 400W. In order to estimate the drag reduction, time-averaged drag force is measured by a force balance system and stagnation pressure history is synchronized with corresponding sequential schlieren images captured by high-speed camera. Drag reduction performance is linearly increased up to 21% with input laser power. The power gain which only depends on the pulse energy, is realized by approximately 7. Virtual spike formation induced by highrepetitive energy depositions is remarkably discussed in the visualization results.

Analysis of the Forces on a Nuclear Fuel Transport Flask in an Impact by a Train

1987 ◽  
Vol 201 (1) ◽  
pp. 55-68 ◽  
Author(s):  
J C Miles ◽  
T C K Molyneaux ◽  
H J Dowler
Keyword(s):  
Mathematical Modelling ◽  
High Speed ◽  
High Speed Train ◽  
Energy Agency ◽  
The Public ◽  
Rail Network ◽  
Analytical Work ◽  
The Impact ◽  
Public Demonstration ◽  
Primary Impact

The majority of fuel transport flask movements is on the public rail network and there has been concern over the possible consequences in the unlikely event of an accident involving a flask. To allay these concerns the Central Electricity Generating Board (CEGB) embarked on a programme of research into the behaviour of flasks in accidents culminating in the public demonstration of a train imapct in July 1984. The train crash demonstration was preceded by extensive analytical work directed at estimating the forces, effects and resulting motions of the primary impact. The mathematical modelling and analyses are described, with an earlier study of a high-speed train (HST) impact, and subsequent comparisons between the predictive estimates and the results of the demonstration. The impact effects expected and found are given in detail, with conclusions on the success of the estimating work and the relative severity of the IAEA (International Atomic Energy Agency) 9 m drop test compared with the train crash.

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