Browsing by Author "Intaratep, Nanyaporn"
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- Aerodynamic Validation of Wind Turbine Airfoil Models in the Virginia Tech Stability Wind TunnelKuester, Matthew; Brown, Kenneth; Meyers, Timothy; Intaratep, Nanyaporn; Borgoltz, Aurelien; Devenport, William J. (Virginia Tech, 2015-06-09)
- The Development of Remote Laboratory Sessions at the Stability Wind Tunnel of Virginia Tech During the Coronavirus PandemicSzőke, Máté; Borgoltz, Aurelien; Kuester, Matthew; Intaratep, Nanyaporn; Devenport, William J.; Katz, Andrew (2021-01-01)This paper discusses the remote delivery of wind tunnel experiments performed at the Stability Wind Tunnel of Virginia Tech, in April 2020, during the early stages of the coronavirus pandemic. The originally in-person laboratories were transformed to entirely remote sessions, on a time-frame of a few weeks, to ensure the delivery of the laboratory sessions and the safety of all participants via social distancing and the use of widely-available video conferencing software. The paper outlines the structure of the laboratory sessions, comprising the tour of the facility, data acquisition, and data visualization alongside with all information technology components used to ensure the successful remote delivery of the laboratory sessions. After the two-week-long experimental campaign, participating students provided feedback on the efficacy of the laboratories via a detailed questionnaire. It was found that the students were highly satisfied with the remote delivery of the laboratory sessions but showed a preference for in-person laboratories.
- Formation and Development of the Tip Leakage Vortex in a Simulated Axial Compressor with Unsteady InflowIntaratep, Nanyaporn (Virginia Tech, 2006-02-23)The interaction between rotor blade tip leakage vortex and inflow disturbances, such as encountered in shrouded marine propulsors, was simulated in the Virginia Tech Linear Cascade Wind Tunnel equipped with a moving endwall system. Upstream of the blade row, idealized periodic inflow unsteadiness was generated using vortex generator pairs attached to the endwall at the same spacing as the blade spacing. At three tip gap settings, 1.7%c, 3.3%c and 5.7%c, the flow near the lower endwall of the center blade passage was investigated through three-component mean velocity and turbulence distributions measured by four-sensor hotwires. Besides time-averaged data, the measurements were processed for phase-locked analysis, with respect to pitchwise locations of the vortex generators relative to the blade passage. Moreover, surface pressure distributions at the blade tip were acquired at eight tip gaps from 0.87%c to 12.9%c. Measurements of pressure-velocity correlation were also performed with wall motion but without inflow disturbances. Achieved in this study is an understanding of the characteristics and structures of the tip leakage vortex at its initial formation. The mechanism of the tip leakage vortex formation seems to be independent of the tip gap setting. The tip leakage vortex consists of a vortical structure and a region of low streamwise-momentum fluid next to the endwall. The vortical structure is initially attached to the blade tip that creates it. This structure picks up circulation shed from that blade tip, as well as those from the endwall boundary layer, and becomes stronger with downstream distance. Partially induced by the mirror images in the endwall, the vortical structure starts to move across the passage resulting in a reduction in its rotational strength as the cross sectional area of the vortex increases but little circulation is added. The larger the tip gap, the longer the vortical structure stays attached to the blade tip, and the stronger the structure when it reaches downstream of the passage. Phased-averaged data show that the inflow disturbances cause small-scale responses and large-scale responses upstream and downstream of the vortex shedding location, respectively. This difference in scale is possibly dictated by a variation in the shedding location since the amount of circulation in the vortex is dependent on this location. The inflow disturbances possibly cause a variation in the shedding location by manipulating the separation of the tip leakage flow from the endwall and consequently the flow's roll-up process. Even though this manipulation only perturbs the leakage flow in a small scale, the shedding mechanism of the tip leakage vortex amplifies the outcome.
- The Investigation of an Inboard-Winglet Application to a Roadable AircraftIntaratep, Nanyaporn (Virginia Tech, 2002-05-31)The inboard-winglet concept was examined for its flow characteristics by testing for pressure coefficients over the wing and winglet surface in the Virginia Tech Stability Wind Tunnel over a range of freestream velocity and angle of attack. The results were analytically applied to calculate aircraft performance of a roadable aircraft, Pegasus II, which used the inboard-winglet concept in its design. The results proved that this concept has the potential to increase a wing lift coefficient at the right combination of thrust setting and freestream velocity better than a conventional wing-propeller arrangement. The lift coefficient inside the winglet channel was approximated as 2D in behavior. It is also shown that the winglets produce thrust at a positive-lift wing configuration. In the Pegasus II, the vertical stabilizers act like inboard winglets and produce a thrust component from its resultant force, giving 5.2% improvement in its effective aspect ratio and resulting in an induced-drag decrease. With an application of the new wing concept, the Pegasus II performance is comparable to other general aviation aircraft.
- Laser Displacement Sensors for Wind Tunnel Model Position MeasurementsKuester, Matthew; Intaratep, Nanyaporn; Borgoltz, Aurelien (MDPI, 2018-11-22)Wind tunnel measurements of two-dimensional wing sections, or airfoils, are the building block of aerodynamic predictions for many aerodynamic applications. In these experiments, the forces and pitching moment on the airfoil are measured as a function of the orientation of the airfoil relative to the incoming airflow. Small changes in this angle (called the angle of attack, or α ) can create significant changes in the forces and moments, so accurately measuring the angle of attack is critical in these experiments. This work describes the implementation of laser displacement sensors in a wind tunnel; the sensors measured the distance between the wind tunnel walls and the airfoil, which was then used to calculate the model position. The uncertainty in the measured laser distances, based on the sensor resolution and temperature drift, is comparable to the uncertainty in traditional linear encoder measurements. Distances from multiple sensors showed small, but statistically significant, amounts of model deflection and rotation that would otherwise not have been detected, allowing for an improved angle of attack measurement.