• Journal of computational fluids engineering
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• v.15 no.3
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• pp.32-38
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• 2010

Aerodynamic design of the vane type multi-function probe was tried by using CFD and wind tunnel test for the MALE UAV and small business jets. The present multi-function probe can measure total pressure, static pressure and angle of attack by using rotating vane. Therefore, major performances are determined by aerodynamic characteristics of vane. In order to design the sensor compatible to the requirement, aerodynamic characteristics of sensors were investigated by using CFD and dynamic response analysis was also performed for transient performance. The final aerodynamic performance was measured by the wind tunnel test at Aerosonic and the results were compared with the present design. The results showed that the aerodynamic design using the CFD can be successfully used for the design of vane type multi-function air data sensor.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.43-49
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• 2010

Aerodynamic design of the vane type multi-function probe was tried by using CFD and wind tunnel test for the MALE UAV and small business jets. The present multi-function probe can measure total pressure, static pressure and angle of attack by using rotating vane. Therefore major performances are determined by aerodynamic characteristics of vane. In oder to design the sensor compatible to the requirement, aerodynamic characteristics of sensors was investigated by using CFD and dynamic response analysis was also performed for trasient performance. The final aerodynamic performance was measured by the wind tunnel test at Aeorsonic and the results successfully used for the design of vane type multi-function air data sensor.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2A
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• pp.97-104
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• 2011

This study presents the aerodynamic admittance function of bridge girder under turbulent flow generated from wind velocity spectrum measured at bridge site. Three dimensional buffeting analysis of concrete cable-stayed bridge were performed considering aerodynamic admittance functions obtained from four different methods. It is revealed from the analysis that vertical buffeting responses considering proper aerodynamic admittance functions were just half of that neglecting aerodynamic admittance function. Grid turbulence was found to relatively lower the aerodynamic admittance function at low frequency range, and to underestimate the buffeting wind forces. It is recommended to use the aerodynamic admittance function evaluated from flutter derivatives or measured at active turbulence in order to properly predict the buffeting responses of bridges.

• Wind and Structures
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• v.13 no.3
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• pp.293-307
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• 2010

This paper describes a new method for the estimation of six complex aerodynamic admittance functions. The aerodynamic admittance functions relate buffeting forces to the incoming wind turbulent components, of which the estimation accuracy affects the prediction accuracy of the buffeting response of long-span bridges. There should be two aerodynamic admittance functions corresponding to the longitudinal and vertical turbulent components, respectively, for each gust buffeting force. Therefore, there are six aerodynamic admittance functions in all for the three buffeting forces. Sears function is a complex theoretical expression for the aerodynamic admittance function for a thin airfoil. Similarly, the aerodynamic admittance functions for a bridge deck should also be complex functions. This paper presents a separated frequency-by-frequency method for estimating the six complex aerodynamic admittance functions. A new experimental methodology using an active turbulence generator is developed to measure simultaneously all the six complex aerodynamic admittance functions. Wind tunnel tests of a thin plate model and a streamlined bridge section model are conducted in turbulent flow. The six complex aerodynamic admittance functions, determined by the developed methodology are compared with the Sears functions and Davenport's formula.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.2
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• pp.85-88
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• 2008

Several parameters are used for the assessment of phonatory function and voice quality in clinical settings. Glottic airflow, subglottal pressure, mean phonation time, laryngeal resistance and voice efficiency are the most commonly used aerodynamic parameters. Aerodynamic analysis is developed to evaluate phonatory energy source and to estimate laryngeal efficiency. Also these measurements have shown the good correlation with perceptions of breathiness and findings of glottic competence. Aerodynamic study is important to understand relationships between pulmonary and phonatory function.

• Speech Sciences
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• v.12 no.4
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• pp.203-213
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• 2005

This study was conducted to investigate the respiratory and aerodynamic function of adductor spasmodic dysphonia (ADSD) patients. Participants were (1) 18 females SD patients with non- Botulinum toxin injection (2) 14 females SD patients who had taken treatment of Botulinum toxin injection. (3) 14 age- and sex- matched normal female controls. Spirometer and phonatory function analyzer were used for respiratory muscle pressure (MIP: Maximum inspiratory pressure), MEP: Maximum expiratory pressure)& MPT(Maximum phonation time) and aerodynamic(F0:Fundamental frequency, intensity, MFR: Mean flow late, Psub: Subglottal pressure) measurement. The results were as follows: (1) Normal group was significantly higher in MIP, MEP, MPT than two SD groups (p < .05); (2) MPT was significantly lower in SD with non-Botulinum toxin injection group than SD with the treatment experience of Botulinum toxin injection (p < .05); (3) All aerodynamic parameters, F0, intensity, MFR, Psub, were not significantly different among three groups(p > .05).The reason of short MPT in ADSD may use lower respiratory pressure than normal group as strategy to decrease their tremulous voice quality. Moreover respiratory muscle pressure was lower than normal group regardless of botulinum toxin injection treatment.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.1
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• pp.99-104
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• 2013

Configuration design, analysis, and wind tunnel test of a vane-type multi-function air data probe (MFP) was described. First, numerical analysis was conducted for the initial configuration of the MFP in order to investigate aerodynamic characteristics. Then, the design was modified to improve static and dynamic stability for better response characteristics. The modified configuration design was verified through wind tunnel tests. The test results are also used to verify the accuracy of the analytical method. The analytically estimated aerodynamic damping provided by the Navier-Stokes equation solver correlated well with the wind tunnel test results. According to the calculation, the damping coefficient estimated from ramp motion analysis yielded a better correlation with the wind tunnel test than pitch oscillation analysis.

• Journal of computational fluids engineering
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• v.17 no.2
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• pp.28-34
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• 2012

In this study, the reliability-based design optimization of the airfoil was performed. PARSEC function was used to consider the uncertainty of the aerodynamic shape for the reliability-based shape optimization of airfoils. Among various reliability analysis methods, the moment method was used to compute the probability of failure of the aerodynamic performance. The accuracy of the reliability analysis was compared with other methods and it was found that the moment method predicts the probability of failure accurately. Deterministic and reliability-based optimizations were performed for the shape of the airfoil and it was demonstrated that reliability-based optimum assures the aerodynamic performances under uncertainties of the shape of the airfoil.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.512-515
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• 2009

This research describes on airfoil shape design, crucial to core technique and algorithm optimization for the wind turbine blade development. We grasped the parameter to define the airfoil shape in the wind turbine blade and aircraft, and the important performance characteristic of the airfoil. The airfoil shape function is selected by studying which is suitable for wind turbine blade airfoil development. The selected method is verified by to compare the generated airfoil shape with base airfoil. The new airfoils were created by the selecting shape function based on the well-known airfoil for wind turbine blades. In addition, we performed aerodynamic analysis about the generated airfoils by XFOIL and estimated the point of difference in the airfoil shape parameter using the aerodynamic performance results which is compared with basic airfoil. This result data applies to the fundamental research for a wind turbine blade optimization design and accomplished the aerodynamic analysis manual.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.50-54
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• 2010

In this study, reliability-based design optimizations of airfoils were performed. PARSEC function was used to consider the uncertainty of the aerodynamic shape for the reliability-based shape optimization of airfoils. Among aerodynamic performance. The accuracy of the reliability analysis was compared with other method and it was found that the moment method predicts the probability accurately. Deterministic and reliability-based optimizations were performed for shape of the RAE2822 airfoil and it was demonstrated that reliability-based optimizations the aerodynamic performances under uncertainties of the shape of the airfoil.