scholarly journals Aerodynamic Analysis of a Supersonic Transport Aircraft at Landing Speed Conditions

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6615
Author(s):  
Andrea Aprovitola ◽  
Pasquale Emanuele Di Nuzzo ◽  
Giuseppe Pezzella ◽  
Antonio Viviani
Keyword(s):  
High Speed ◽  
Cfd Simulation ◽  
Vortex Breakdown ◽  
Delta Wing ◽  
Research Effort ◽  
Static Stability ◽  
Commercial Aviation ◽  
Supersonic Flight ◽  
Supersonic Transport ◽  
Wide Range

Supersonic flight for commercial aviation is gaining a renewed interest, especially for business aviation, which demands the reduction of flight times for transcontinental routes. So far, the promise of civil supersonic flight has only been afforded by the Concorde and Tupolev T-144 aircraft. However, little or nothing can be found about the aerodynamics of these aeroshapes, the knowledge of which is extremely interesting to obtain before the development of the next-generation high-speed aircraft. Therefore, the present research effort aimed at filling in the lack of data on a Concorde-like aeroshape by focusing on evaluating the aerodynamics of a complete aircraft configuration under low-speed conditions, close to those of the approach and landing phase. In this framework, the present paper focuses on the CFD study of the longitudinal aerodynamics of a Concorde-like, tailless, delta-ogee wing seamlessly integrated onto a Sears–Haack body fuselage, suitable for civil transportation. The drag polar at a Mach number equal to 0.24 at a 30 m altitude was computed for a wide range of angles of attack (0∘,60∘), with a steady RANS simulation to provide the feedback of the aerodynamic behaviour post breakdown, useful for a preliminary design. The vortex-lift contribution to the aerodynamic coefficients was accounted for in the longitudinal flight condition. The results were in agreement with the analytical theory of the delta-wing. Flowfield sensitivity to the angle of attack at near-stall and post-stall flight attitudes confirmed the literature results. Furthermore, the longitudinal static stability was addressed. The CFD simulation also evidenced a static instability condition arising for 15∘≤α≤20∘ due to vortex breakdown, which was accounted for.

CFD SIMULATION AND CHARACTERIZATION OF A DEVICE FOR POWDERED PHARMACEUTICALS AND BIOLOGICALS DELIVERY

2006 ◽  
Vol 06 (03) ◽  
pp. 285-297
Author(s):  
FANG LIU ◽  
WEI HE ◽  
CHUNLI CAO ◽  
YI LIU
Keyword(s):  
High Speed ◽  
Cfd Simulation ◽  
Biological Effects ◽  
Particle Interaction ◽  
Mean Velocity ◽  
Micro Particles ◽  
Venturi Effect ◽  
Underlying Principle ◽  
Wide Range

Advances in molecular biology have produced a wide range of protein and peptide-based drugs. Equally, it is required to explore various technologies and capabilities to deliver those drugs. A unique medical device, the hand-held biolistics, is developed for powdered pharmaceuticals/biologicals transdermal delivery. The underlying principle is to accelerate micro-particles by means of a high-speed helium gas to an appropriate momentum to penetrate the outer layer of the skin to elicit desirable pharmaceutical/biological effects. The novelty of this hand-held biolistics is using the venturi effect to entrain micron-sized protein and peptide drugs into an established quasi-steady transonic jet flow and accelerate them toward the target. In this paper, computational fluid dynamics is utilized to characterize prototype biolistic system. The key features of gas dynamics and gas–particle interaction are presented. The overall capability of the biolistic delivery system is discussed and demonstrated. The statistical analyses show that the particles have achieved a mean velocity of 628 m/s as representatives of extracellular vaccine delivery applications.

A Multidisciplinary Analysis of Tail Buffeting Alleviation Using Streamwise Fences

2003 ◽  
Vol 9 (5) ◽  
pp. 583-604 ◽  
Author(s):  
Essam F. Sheta
Keyword(s):  
Data Transfer ◽  
Vortex Breakdown ◽  
Delta Wing ◽  
Vortical Flow ◽  
Geometrical Shape ◽  
Fighter Aircraft ◽  
Grid Deformation ◽  
Multidisciplinary Analysis ◽  
Wide Range ◽  
High Angles Of Attack

A multidisciplinary analysis of vertical tail buffeting and buffeting alleviation of generic fighter aircraft is conducted. This complex multidisciplinary problem is solved for the fluid dynamics, structure dynamics, fluid-structure coupling, and grid deformation using a computing environment that controls the temporal synchronization of the data transfer between the analysis modules. The generic fighter aircraft consists of a sharp-edged delta wing with an aspect ratio of one and a swept-back, flexible, vertical twin tail with a taper ratio of 0.23. Twin streamwise fences are located at the 30% chord-station of the delta wing. The fences are used to alter the vortical flow and to delay the onset of vortex breakdown above the delta wing, in order to alleviate the twin-tail buffeting. The effect of the geometrical shape of the fences on the buffeting responses is investigated. The performance of the fences over a wide range of high angles of attack is also investigated. The trapezoidal configuration of the fences at a taper ratio of 0.7 produced the most favorable results. The results indicated that the fences are effective in reducing the aeroelastic loads and responses, especially at angles of attack less than 30°.

A review of pressure-sensitive paint for high-speed and unsteady aerodynamics

2008 ◽  
Vol 222 (2) ◽  
pp. 249-290 ◽  
Author(s):  
J W Gregory ◽  
K Asai ◽  
M Kameda ◽  
T Liu ◽  
J P Sullivan
Keyword(s):  
High Speed ◽  
Response Times ◽  
Delta Wing ◽  
Unsteady Aerodynamics ◽  
Gas Diffusion ◽  
Current Paper ◽  
Step Response ◽  
Pressure Sensitive Paint ◽  
Pressure Sensitive ◽  
Wide Range

The current paper describes the development of pressure-sensitive paint (PSP) technology as an advanced measurement technique for unsteady flow fields and short-duration wind tunnels. Newly developed paint formulations have step response times approaching 1 μs, making them suitable for a wide range of unsteady testing. Developments in binder technology are discussed, which have resulted in new binder formulations such as anodized aluminium, thin-layer chromatography plate, polymer/ceramic, and poly(TMSP) PSP. The current paper also details modeling work done to describe the gas diffusion properties within the paint binder and understand the limitations of the paint response characteristics. Various dynamic calibration techniques for PSP are discussed, along with summaries of typical response times. A review of unsteady and high-speed PSP applications is presented, including experiments with shock tubes, hypersonic tunnels, unsteady delta wing aerodynamics, fluidic oscillator flows, Hartmann tube oscillations, acoustics, and turbomachinery. Flowfields with fundamental frequencies as high as 21 kHz have been successfully measured with porous PSP formulations.

Vortex interaction and breakdown over double-delta wings

2004 ◽  
Vol 108 (1079) ◽  
pp. 27-34 ◽  
Author(s):  
S. L. Gai ◽  
M. Roberts ◽  
A. Barker ◽  
C. Kleczaj ◽  
A. J. Riley
Keyword(s):  
High Speed ◽  
Passive Control ◽  
Fluorescent Dyes ◽  
Vortex Breakdown ◽  
Delta Wing ◽  
Laser Sheet ◽  
Diagnostic Methods ◽  
Flow Visualisation ◽  
Delta Wings ◽  
Pressure Sensitive

Modern high-speed aircraft, especially military, are very often equipped with single or compound delta wings. When such aircraft operate at high angles-of-attack, the major portion of the lift is sustained by streamwise vortices generated at the leading edges of the wing. This vortex-dominated flow field can breakdown, leading not only to loss of lift but also to adverse interactions with other airframe components such as the fin or horizontal tail. The wind tunnel and water studies described herein attempt to clarify the fluid mechanics of interaction between the strake and wing vortices of a generic 76°/40° double-delta wing leading to vortex breakdown. Some studies of passive control using fences at the apex and kink region are also described. Various diagnostic methods-laser sheet flow visualisation, fluorescent dyes, and pressure sensitive paints have been used.

A High-Speed Disk Rotor Rig Design for Tip Aerothermal Research

2020 ◽  
Author(s):  
S. Lu ◽  
Q. Zhang ◽  
L. He
Keyword(s):  
High Speed ◽  
Cfd Simulation ◽  
Optical Measurement ◽  
Design Concept ◽  
System Level ◽  
Tip Leakage Flow ◽  
Component Level ◽  
Tip Leakage ◽  
Rotor Design ◽  
Wide Range

Abstract The relative casing motion can greatly vary the Over-Tip-Leakage (OTL) flow structure and thermal performance. The existing tip experimental research facilities include stationary linear cascade, cascade rigs with low speed moving belt, or high-speed rotor rigs are either not capable of reproducing the high relative casing Mach number, or extremely expensive and still difficult for optical measurement. This paper presents a highspeed disk rotor design which can simulate the high casing relative speed. The unique feature of this rig design concept is that it enables full optical access of the tip surface under the engine-representative OTL flow condition. In this paper, the feasibility of the design concept is demonstrated and assessed by RANS CFD simulation, both in component level and whole rig system level. The design idea demonstrated in this paper can be useful for a wide range of tip leakage flow studies.

CFD Simulation for Turbulent Flow Past NACA4412 Aerofoil

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
C. Manjunath ◽  
G.H. Somesha ◽  
Sekhar Majumdar
Keyword(s):  
Fluid Dynamics ◽  
Reynolds Number ◽  
Turbulent Flow ◽  
High Speed ◽  
Cfd Simulation ◽  
Measurement Data ◽  
Curvilinear Coordinates ◽  
Flow Past ◽  
Wide Range ◽  
Low Reynolds

The complex fluid dynamics of different flow situations at low Reynolds number for natural flying objects like birds and insects, needs to be clearly understood for arriving at an optimum design for sizes ranging from the small man-made ones to very large size high speed commercial aircrafts or the fighter aircrafts. Airfoil performance at low Reynolds numbers impacts the performance of a wide range of systems. Computational Fluid Dynamics (CFD) tools have been around for a couple of decades now. With the superfast growth of computing power, speed and accuracy of these mathematical tools have improved to a considerable extent. However, any CFD simulation employing turbulence models needs to be validated against reliable and accurate measurement data obtained from wind tunnels. The present work focuses on 2D numerical simulation of turbulent flow past a symmetric NACA4412 aerofoil, using C- grid topology, for a Reynolds number of 1 million and 3 million. The computation uses the CFD code RANS3D, an implicit, pressure-based finite volume type Reynolds averaged Navier-stokes solver in generalized non-orthogonal curvilinear coordinates.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Diamond, cropped, delta, and double-delta wing vortex breakdown during dynamic pitching

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 567-569
Author(s):  
Roy Y. Myose ◽  
Boon-Kiat Lee ◽  
Shigeo Hayashibara ◽  
L. S. Miller
Keyword(s):  
Vortex Breakdown ◽  
Delta Wing ◽  
Double Delta Wing

Factors Affecting Driver Injury Severity in the Wrong-Way Crash: Accounting for Potential Heterogeneity in Means and Variances of Random Parameters

2021 ◽  
pp. 036119812110098
Author(s):  
Miao Yu ◽  
Jinxing Shen ◽  
Changxi Ma
Keyword(s):  
High Speed ◽  
Injury Severity ◽  
Unobserved Heterogeneity ◽  
Research Effort ◽  
Random Parameter ◽  
Policy Implications ◽  
Contributing Factors ◽  
Severe Injuries ◽  
Data Set ◽  
Severity Levels

Because of the high percentage of fatalities and severe injuries in wrong-way driving (WWD) crashes, numerous studies have focused on identifying contributing factors to the occurrence of WWD crashes. However, a limited number of research effort has investigated the factors associated with driver injury-severity in WWD crashes. This study intends to bridge the gap using a random parameter logit model with heterogeneity in means and variances approach that can account for the unobserved heterogeneity in the data set. Police-reported crash data collected from 2014 to 2017 in North Carolina are used. Four injury-severity levels are defined: fatal injury, severe injury, possible injury, and no injury. Explanatory variables, including driver characteristics, roadway characteristics, environmental characteristics, and crash characteristics, are used. Estimation results demonstrate that factors, including the involvement of alcohol, rural area, principal arterial, high speed limit (>60 mph), dark-lighted conditions, run-off-road collision, and head-on collision, significantly increase the severity levels in WWD crashes. Several policy implications are designed and recommended based on findings.

Sign in / Sign up

Export Citation Format

Share Document