Measurement of ground effect and boundary-layer transition by towing wind tunnel

Yoshioka, Shuya; Kikuchi, Satoshi; Ohta, Fukuo; Kato, Takuma; Kohama, Yasuaki

doi:10.1088/0169-5983/41/2/021408

Cited by 5 publications

(3 citation statements)

References 7 publications

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“…The facility that was eventually identified and selected for this study was the Towing Wind Tunnel at Tohoku University's Sunrise Beach Research Facility in Hyuga, Japan. 9 This facility was not a conventional wind tunnel, but rather a very long test track with an electric vehicle that carries the test model.…”

Section: Excrescence Testing For Pressure Gradient Effectsmentioning

confidence: 99%

Step Excrescence Effects for Manufacturing Tolerances on Laminar Flow Wings

Drake

Bender

Korntheuer

et al. 2010

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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Manufacturing tolerances for laminar flow wings can be significantly tighter than those of conventional aircraft. The tighter tolerances can significantly affect the assessment of the practicality of designing for laminar flow. However, existing data on the effects of excrescences typical of manufacturing process are limited. Further, information on the effects-often beneficial-of pressure gradient present on the laminar flow wings is not generally available. To address these concerns, a series of experiments has been undertaken to examine the effects of surface steps in the presence of pressure gradients. The step geometries were selected to represent those that result from actual aircraft manufacturing processes. The range of pressure gradients correspond to those typical of laminar flow wings. Initial experiments were conducted in a low-speed wind tunnel. Later experiments used a novel propelled-model test facility. The results of these studies show that the allowable sizes of surface excrescences for laminar flow wings may be significantly greater than has conventionally been assumed. This could significantly influence the more widespread use of laminar flow for drag reduction, resulting in more efficient aircraft.

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Section: Excrescence Testing For Pressure Gradient Effectsmentioning

confidence: 99%

Step Excrescence Effects for Manufacturing Tolerances on Laminar Flow Wings

Drake

Bender

Korntheuer

et al. 2010

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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“…The experiments were performed in the Towing Wind Tunnel facility 10 , which is owned and operated by Tohoku University. The facility is located in Hyuga, Miyazaki Prefecture, Japan.…”

Section: Approach and Instrumentationmentioning

confidence: 99%

Hot-Wire Measurements of the Influence of Surface Steps on Transition in Favorable Pressure Gradient Boundary Layers

Gerashchenko

McKeon

Westphal

et al. 2010

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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An examination of the effects of surface step excrescences on boundary layer transition was performed, using a unique experimental facility. The objective of the work was to characterize the variation of transition Reynolds numbers with measurable step size and boundary layer parameters, with the specific goal of specifying new tolerance criteria for laminar flow airfoils, alongside a fundamental investigation of boundary layer transition mechanisms. This paper focuses on interpretation of hot-wire measurements, including supporting stability calculations, undertaken as part of the study. The results for both forward and aft-facing steps indicated a substantial stabilizing effect of favorable pressure gradient on excrescence-induced boundary layer transition. These findings suggest that manufacturing tolerances for laminar flow aircraft could be loosened in areas where even mild favorable pressure gradients exist.

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“…Moreover, to run the models at sufficient speed requires a large space in terms of both length and cross section. Therefore, we installed the facility in the "Towing Wind Tunnel Facility" 6) of Tohoku University shown in Fig.1, which…”

Section: Introductionmentioning

confidence: 99%

Development of a Model Running Facility for a Study on under-floor Flow

Ido

Yoshioka

2010

JMTL

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We developed a model running facility to study the flow of the under-floor of railway car. The facility was set up in the test section of the Towing Wind Tunnel Facility where by a hood we can eliminate disturbances, such as natural wind. We carried out the model running tests and measured the velocity distribution under the model car. The velocity distribution was almost the same as in the rear cars from the car No.3, and the velocity between the rails was less than the velocity outside of the rail.

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Measurement of ground effect and boundary-layer transition by towing wind tunnel

Cited by 5 publications

References 7 publications

Step Excrescence Effects for Manufacturing Tolerances on Laminar Flow Wings

Step Excrescence Effects for Manufacturing Tolerances on Laminar Flow Wings

Hot-Wire Measurements of the Influence of Surface Steps on Transition in Favorable Pressure Gradient Boundary Layers

Development of a Model Running Facility for a Study on under-floor Flow

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