10 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Mechanics 170602* -- Wind Energy Engineering-- Turbine Design & Operation"  
Results: 1 - 10
open access

Wind velocity-change (gust rise) criteria for wind turbine design

Description: A closed-form equation is derived for root mean square (rms) value of velocity change (gust rise) that occurs over the swept area of wind turbine rotor systems and an equation for rms value of velocity change that occurs at a single point in space. These formulas confirm the intuitive assumption that a large system will encounter a less severe environment than a small system when both are placed at the same location. Assuming a normal probability density function for the velocity differences, a… more
Date: July 1, 1978
Creator: Cliff, W. C. & Fichtl, G. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Turbulence spectrum observed by a fast-rotating wind-turbine blade

Description: The spectrum of turbulence encountered by a point on a fast-rotating wind turbine blade is shown to be possibly quite different from that measured by a stationary anemometer. The physically reasonable expectations are supported quantitatively by experiments using Pacific Northwest Laboratory's vertical-plane anemometer array. The measurements indicate that the blade encounters energy densities in two regions of the turbulence spectrum much different than those seen by stationary anemometers. Fo… more
Date: June 1, 1980
Creator: Connell, J. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Security assessment of power systems including energy storage and with the integration of wind energy. Progress report, July 1-September 30, 1979

Description: The progress of the first three tasks of the wind energy part of the contract is discussed. Emphasis is on the modeling of the wind and the detailed computer representations of three candidate wind systems; namely, MOD-1, MOD-2 and the Shackle machine. Once the detailed computer representations of these wind systems have been developed the next step is to begin work on the reduced order models to be used in transient stability programs.
Date: October 1, 1979
Creator: Carroll, D.P. & Krause, P.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Wind energy conversion. Volume IX. Aerodynamics of wind turbine with tower disturbances

Description: Lifting line theory which is the counterpart of Prandtl's lifting line theory for rotating wing is employed for the overall performance analysis of a horizontal axis wind turbine rotor operating in a uniform flow. The wake system is modeled by non-rigid wake which includes the radial expansion and the axial retardation of trailing vortices. For the non-uniform flow which are caused by the ground, the tower reflection, or the tower shadow, the unsteady airloads acting on the turbine blade are co… more
Date: September 1, 1978
Creator: Chung, S.Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Wind direction change criteria for wind turbine design

Description: A method is presented for estimating the root mean square (rms) value of the wind direction change, ..delta..theta(tau) = theta(tau + tau) - theta(tau), that occurs over the swept area of wind turbine rotor systems. An equation is also given for the rms value of the wind direction change that occurs at a single point in space, i.e., a direcion change that a wind vane would measure. Assuming a normal probability density function for the lateral wind velocity change and relating this to angular c… more
Date: January 1, 1979
Creator: Cliff, W.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Experimental and analytical research on the aerodynamics of wind turbines. Mid-term technical report, June 1--December 31, 1975

Description: The successful development of reliable, cost competitive horizontal axis, propeller-type wind energy conversion systems (WECS) is strongly dependent on the availability of advanced technology for each of the system components. Past experience and current studies of this type of wind energy conversion systems have shown that the wind turbine subsystem most significantly effects the system's cost effectiveness and performance capability. Thus adequate technology bases are essential for all elemen… more
Date: February 1, 1976
Creator: Rohrbach, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Preliminary results of a field experiment to characterize wind flow through a vertical plane

Description: Preliminary results are presented of a field experiment to study the turbulent structure in the wind flow through a simulated disc of rotation of a large, horizontal-axis wind turbine blade. The wind flow impinging on the hypothetical turbine blade was simulated by a nine-element circular array of three component anemometers in a single vertical plane. The wind data were analyzed as: a single point, hub height measurement (at the center of the array); an arithmetic average of all sensors; and a… more
Date: April 1, 1978
Creator: Verholek, M. Gary
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Wind energy conversion. Volume X. Aeroelastic stability of wind turbine rotor blades

Description: The nonlinear equations of motion of a general wind turbine rotor blade are derived from first principles. The twisted, tapered blade may be preconed out of the plane of rotation, and its root may be offset from the axis of rotation by a small amount. The aerodynamic center, center of mass, shear center, and area centroid are distinct in this derivation. The equations are applicable to studies of forced response or of aeroelastic flutter, however, neither gravity forcing, nor wind shear and gus… more
Date: September 1, 1978
Creator: Wendell, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Free wake analysis of wind turbine aerodynamics. Wind energy conversion. ASRL-TR-184-14

Description: The underlying theory is presented for determining blade and rotor/tower vibration and dynamic stability characteristics as well as the basic dynamic (as opposed to aerodynamic) operating loads. Starting with a simple concept of equivalent hinged rotors, the equations of motion for the blade including pitch, flap and lag motions are developed. The nonlinear equations are derived first and linearized about a finite displacement of the blade out of the plane of rotation. This is important since w… more
Date: September 1, 1978
Creator: Gohard, J.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Full vector (3-D) inflow simulation in natural and wind farm environments using an expanded version of the SNLWIND (Veers) turbulence code

Description: We have recently expanded the numerical turbulence simulation (SNLWIND) developed by Veers [1] to include all three components of the turbulent wind vector. We have also configured the code to simulate the characteristics of turbulent wind fields upwind and downwind of a large wind farm, as well as over uniform, flat terrain. Veers's original method only simulates the longitudinal component of the wind in neutral flow. This paper overviews the development of spectral distribution, spatial coher… more
Date: November 1, 1992
Creator: Kelley, N.D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen