Author: Kimberly R. PetePublisher:
ISBN:
Category : Aeronautics, Commercial
Languages : en
Pages : 210
Book Description
Model Validation for Wake-vortex Aircraft Encounters
Author: Kimberly R. PetePublisher:
ISBN:
Category : Aeronautics, Commercial
Languages : en
Pages : 210
Book Description
Vortex wakes of Aircrafts
Author: A.S. GinevskyPublisher: Springer Science & Business Media
ISBN: 3642017606
Category : Mathematics
Languages : en
Pages : 166
Book Description
Investigation of vortex wakes behind various aircraft, especially behind wide bodied and heavy cargo ones, is of both scientific and practical in terest. The vortex wakes shed from the wing’s trailing edge are long lived and attenuate only atdistances of10–12kmbehindthe wake generating aircraft. The encounter of other aircraft with the vortex wake of a heavy aircraft is open to catastrophic hazards. For example, air refueling is adangerous operationpartly due to thepossibility of the receiver aircraft’s encountering the trailing wake of the tanker aircraft. It is very important to know the behavior of vortex wakes of aircraft during theirtakeoff andlanding operations whenthe wakes canpropagate over the airport’s ground surface and be a serious hazard to other depart ing or arriving aircraft. This knowledge can help in enhancing safety of aircraft’s movements in the terminal areas of congested airports where the threat of vortex encounters limits passenger throughput. Theoreticalinvestigations of aircraft vortex wakes arebeingintensively performedinthe major aviationnations.Usedforthispurpose are various methods for mathematical modeling of turbulent flows: direct numerical simulation based on the Navier–Stokes equations, large eddy simulation using the Navier–Stokes equations in combination with subrigid scale modeling, simulation based on the Reynolds equations closed with a differential turbulence model. These approaches are widely used in works of Russian and other countries’ scientists. It should be emphasized that the experiments in wind tunnels and studies of natural vortex wakes behind heavy and light aircraft in flight experiments are equally important.
A Candidate Wake Vortex Strength Definition for Application to the NASA Aircraft Vortex Spacing System (AVOSS)
Author: David A. HintonPublisher:
ISBN:
Category : Airports
Languages : en
Pages : 38
Book Description
Wake Turbulence
Author: National Research CouncilPublisher: National Academies Press
ISBN: 0309113792
Category : Science
Languages : en
Pages : 102
Book Description
Without major changes, the current air transportation system will be unable to accommodate the expected increase in demand by 2025. One proposal to address this problem is to use the Global Positioning System to enable aircraft to fly more closely spaced. This approach, however, might be limited by the wake turbulence problem, which can be a safety hazard when smaller aircraft follow relatively larger aircraft too closely. To examine how this potential hazard might be reduced, Congress in 2005 directed NASA to request a study from the NRC to assess the federal wake turbulence R&D program. This book provides a description of the problem, an assessment of the organizational challenges to addressing wake turbulence, an analysis of the technical challenges in wake turbulence, and a proposal for a wake turbulence program plan. A series of recommendations for addressing the wake turbulence challenge are also given.
A Preliminary Study of a Wake Vortex Encounter Hazard Boundary for a B737-100 Airplane
Author: Wake Vortex Separation Standards
Author: David BurnhamPublisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 92
Book Description
Wake vortex separation standards are used to prevent hazardous wake vortex encounters. A 'safe' separation model can be used to assess the safety of proposed changes in the standards. A safe separation model can be derived from an encounter hazard model and a vortex decay model. This report presents subsequent developments and applications of such a model which was first developed in the early 1980s. A static encounter hazard model is coupled with a decay model based on sodar measurements of vortex decay. The separation standards and procedures used from 1976 to 1994 are assumed to be safe based on the absence of IFR accidents. Various versions of the model are used to assess how aircraft should be classified and to evaluate the safety of a possible four-class aircraft separation system. Recommendations are made for ways of improving the safe separation models.
Hazard Criteria for Wake Vortex Encounters
Author: Proceedings of the NASA First Wake Vortex Dynamic Spacing Workshop
Author: Leonard CredeurPublisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 632
Book Description
A Method for Assessing the Impact of Wake Vortices of USAF Operations
Author: George KurylowichPublisher:
ISBN:
Category : Helicopters
Languages : en
Pages : 114
Book Description
Experience as a consultant to the Safety Office at Norton AFB led to compiling the engineering tools presented so that this report can be used by engineering personnel to investigate future incidents/accidents and existing USAF operations that are impacted by the vortical wake hazard. The approach presented is amenable to easy hand computations. Mixed airplane/helicopter operations can be assessed, since the engineering tools to determine the location and strength of the rotor downwash field behind a helicopter are presented. Finally, a simplified mathematical model is given to represent this hazard for use in USAF simulators, to make pilots aware of the problems associated with operating in wake-contaminated airspace.
Author: