Investigation of Vortex Flaps and Other Flow Control Devices on Generic High-Speed Civil Transport Planforms
Investigation of Vortex Flaps and Other Flow Control Devices on Generic High-Speed Civil Transport Planforms

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-06-13

Total Pages: 126

ISBN-13: 9781721087426

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A parametric cranked delta planform study has been conducted in the Langley 14- by 22-Foot Subsonic Tunnel with the following objectives: (1) to evaluate the vortex flap design methodology for cranked delta wings, (2) to determine the influence of leading-edge sweep and the outboard wing on vortex flap effectiveness, (3) to evaluate novel flow control concepts, and (4) to validate unstructured grid Euler computer code predictions with modeled vortex and trailing-edge flaps. Two families of cranked delta planforms were investigated. One family had constant aspect ratio, while the other had a constant nondimensional semispan location of the leading-edge break. The inboard leading-edge sweep of the planforms was varied between 68 deg., 71 deg., and 74 deg., while outboard leading-edge sweep was varied between 48 deg. and 61 deg. Vortex flaps for the different planforms were designed by an analytical vortex flap design method. The results indicate that the effectiveness of the vortex flaps was only slightly influenced by the variations in the parametric planforms. The unstructured grid Euler computer code was successfully used to model the configurations with vortex flaps. The vortex trap concept was successfully demonstrated. Kjerstad, Kevin J. and Campbell, Bryan A. and Gile, Brenda E. and Kemmerly, Guy T. Langley Research Center RTOP 537-03-22-02

Low Speed Analysis of Mission Adaptive Flaps on a High Speed Civil Transport Configuration
Low Speed Analysis of Mission Adaptive Flaps on a High Speed Civil Transport Configuration

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-06-03

Total Pages: 82

ISBN-13: 9781720616757

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Thin-layer Navier-Stokes analyses were done on a high speed civil transport configuration with mission adaptive leading-edge flaps. The flow conditions simulated were Mach = 0.22 and Reynolds number of 4.27 million for angles-of-attack ranging from 0 to 18 degrees. Two turbulence closure models were used. Analyses were done exclusively with the Baldwin-Lomax turbulence model at low angle-of-attack conditions. At high angles-of-attack where considerable flow separation and vortices occurred the Spalart-Allmaras turbulence model was also considered. The effects of flow transition were studied. Predicted aerodynamic forces, moment, and pressure are compared to experimental data obtained in the 14- by 22-Foot Subsonic Tunnel at NASA Langley. The forces and moments correlated well with experimental data in terms of trends. Drag and pitching moment were consistently underpredicted. Predicted surface pressures compared well with experiment at low angles-of-attack. Above 10 angle-of-attack the pressure comparisons were not as favorable. The two turbulent models affected the pressures on the flap considerably and neither produced correct results at the high angles-of-attack.Lessard, Victor R.Langley Research CenterTHIN FILMS; LOW SPEED; FLAPPING; TURBULENCE MODELS; PITCHING MOMENTS; MATHEMATICAL MODELS; LEADING EDGE FLAPS; BOUNDARY LAYER SEPARATION; BALDWIN-LOMAX TURBULENCE MODEL; VORTICES; TURBULENT FLOW; TRENDS; SUPERSONIC TRANSPORTS; SUBSONIC WIND TUNNELS; SEPARATED FLOW; REYNOLDS NUMBER; NAVIER-STOKES EQUATION; CLOSURE LAW; CIVIL AVIATION; AERODYNAMIC FORCES

Flow Control Through Bio-inspired Leading-Edge Tubercles
Flow Control Through Bio-inspired Leading-Edge Tubercles

Author: Daniel T. H. New

Publisher: Springer Nature

Published: 2020-01-31

Total Pages: 185

ISBN-13: 3030237923

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This book describes and explains the basis of bio-inspired, leading-edge tubercles based on humpback whale flippers as passive but effective flow control devices, as well as providing a comprehensive practical guide in their applications. It first discusses the morphology of the humpback whale flipper from a biological perspective, before presenting detailed experimental and numerical findings from past investigations by various experts on the benefits of leading-edge tubercles and their engineering implementations. Leading-edge tubercle designs and functions have attracted considerable interest from researchers in terms of understanding their role in the underwater agility of these whales, and to exploit their flow dynamics in the development of new and novel engineering solutions. Extensive research over the past recent years has demonstrated that the maneuverability of these whales is at least in part due to the leading-edge tubercles acting as passive flow control devices to delay stall and increase lift in the post-stall regime. In addition to the inherent benefits in terms of aerodynamics and hydrodynamics, investigations into leading-edge tubercles have also broadened into areas of noise attenuation, stability and industrial applications. This book touches upon these areas, with an emphasis upon the effects of lifting-surface types, flow regimes, tubercle geometries, lifting-surface stability and potential industrial applications, among others. As such, it features contributions from key experts in the fields of biology, physics and engineering who have conducted significant studies into understanding the various aspects of leading-edge tubercles. Given the broad coverage and in-depth analysis, this book will benefit academic researchers, practicing engineers and graduate students interested in tapping into such a unique but highly functional flow control strategy.

Recent Progress in Flow Control for Practical Flows
Recent Progress in Flow Control for Practical Flows

Author: Piotr Doerffer

Publisher: Springer

Published: 2017-05-11

Total Pages: 505

ISBN-13: 3319505688

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This book explores the outcomes on flow control research activities carried out within the framework of two EU-funded projects focused on training-through-research of Marie Sklodowska-Curie doctoral students. The main goal of the projects described in this monograph is to assess the potential of the passive- and active-flow control methods for reduction of fuel consumption by a helicopter. The research scope encompasses the fields of structural dynamics, fluid flow dynamics, and actuators with control. Research featured in this volume demonstrates an experimental and numerical approach with a strong emphasis on the verification and validation of numerical models. The book is ideal for engineers, students, and researchers interested in the multidisciplinary field of flow control.