18 Matching Results

Search Results

Advanced search parameters have been applied.

in creator/contributor: "Tangler, J."

open access

The Evolution of Rotor and Blade Design

The objective of this paper is to provide a historical perspective of the evolution of rotor and blade design during the last 20 years. This evolution is a balanced integration of economic, aerodynamic, structural dynamic, noise, and aesthetic considerations, which are known to be machine type and size dependent.

Date: August 1, 2000

Creator: Tangler, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Nebulous Art of Using Wind-Tunnel Airfoil Data for Predicting Rotor Performance: Preprint

The objective of this study was threefold: to evaluate different two-dimensional S809 airfoil data sets in the prediction of rotor performance; to compare blade-element momentum rotor predicted results to lifting-surface, prescribed-wake results; and to compare the NASA Ames combined experiment rotor measured data with the two different performance prediction methods. The S809 airfoil data sets evaluated included those from Delft University of Technology, Ohio State University, and Colorado Sta… more

Date: January 1, 2002

Creator: Tangler, J. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of RCAS Inflow Models for Wind Turbine Analysis

The finite element structural modeling in the Rotorcraft Comprehensive Analysis System (RCAS) provides a state-of-the-art approach to aeroelastic analysis. This, coupled with its ability to model all turbine components, results in a methodology that can simulate complex system interactions characteristic of large wind. In addition, RCAS is uniquely capable of modeling advanced control algorithms and the resulting dynamic responses.

Date: February 1, 2004

Creator: Tangler, J. & Bir, G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Wind tunnel tests of two airfoils for wind turbines operating at high reynolds numbers

The objectives of this study were to verify the predictions of the Eppler Airfoil Design and Analysis Code for Reynolds numbers up to 6 x 106 and to acquire the section characteristics of two airfoils being considered for large, megawatt-size wind turbines. One airfoil, the S825, was designed to achieve a high maximum lift coefficient suitable for variable-speed machines. The other airfoil, the S827, was designed to achieve a low maximum lift coefficient suitable for stall-regulated machines. B… more

Date: June 29, 2000

Creator: Sommers, D. & Tangler, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

SERI advanced wind turbine blades

The primary goal of the Solar Energy Research Institute's (SERI) advanced wind turbine blades is to convert the kinetic energy in the wind into mechanical energy in an inexpensive and efficient manner. To accomplish this goal, advanced wind turbine blades have been developed by SERI that utilize unique airfoil technology. Performance characteristics of the advanced blades were verified through atmospheric testing on fixed-pitch, stall-regulated horizontal-axis wind turbines (HAWTs). Of the vari… more

Date: February 1, 1992

Creator: Tangler, J.; Smith, B. & Jager, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

SERI advanced wind turbine blades

The primary goal of the Solar Energy Research Institute`s (SERI) advanced wind turbine blades is to convert the kinetic energy in the wind into mechanical energy in an inexpensive and efficient manner. To accomplish this goal, advanced wind turbine blades have been developed by SERI that utilize unique airfoil technology. Performance characteristics of the advanced blades were verified through atmospheric testing on fixed-pitch, stall-regulated horizontal-axis wind turbines (HAWTs). Of the vari… more

Date: February 1, 1992

Creator: Tangler, J.; Smith, B. & Jager, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

NREL airfoil families for HAWTs

The development of special-purpose airfoils for horizontal-axis wind turbines (HAWTs) began in 1984 as a joint effort between the National Renewable Energy Laboratory (NREL), formerly the Solar Energy Research Institute (SERI), and Airfoils, Incorporated. Since that time seven airfoil families have been designed for various size rotors using the Eppler Airfoil Design and Analysis Code. A general performance requirement of the new airfoil families is that they exhibit a maximum lift coefficient … more

Date: January 1, 1995

Creator: Tangler, J L & Somers, D M

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Wind Turbine Post-Stall Airfoil Performance Characteristics Guidelines for Blade-Element Momentum Methods: Preprint

The objective of this study was to provide post-stall airfoil data input guidelines for the prediction of peak and post-peak rotor power when using blade-element momentum theory. A steady-state data set from the Unsteady Aerodynamic Experiment (UAE) rotor test was used to provide guidelines for the development of a global post-stall method for the prediction of post-stall 3-D airfoil characteristics to be used with 2-D airfoil data. Based on these UAE data, methods to emulate the 3-D aerodynami… more

Date: October 1, 2004

Creator: Tangler, J. L. & Kocurek, J. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Wind-tunnel test of the S814 thick root airfoil

The objective of this wind-tunnel test was to verify the predictions of the Eppler Airfoil Design and Analysis Code for a very thick airfoil having a high maximum lift coefficient (c{sub 1,max} designed to be largely insensitive to leading edge roughness effects. The 24-percent-thick S814 airfoil was designed with these characteristics to accommodate aerodynamic and structural considerations for the root region of a wind-turbine blade. In addition, the airfoil`s maximum lift-to-drag ratio was d… more

Date: January 1, 1995

Creator: Somers, D.M. & Tangler, J.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measured and predicted rotor performance for the SERI advanced wind turbine blades

Measured and predicted rotor performance for the SERI advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit future rotor design efforts. Propeller/vane anemometers were found to underestimate the wind speed in turbulent environments such as the San Gorgonio Pass … more

Date: February 1, 1992

Creator: Tangler, J.; Smith, B.; Kelley, N. & Jager, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A discussion of the results of the rainflow counting of a wide range of dynamics associated with the simultaneous operation of adjacent wind turbines

The objective of this study was to provide a fatigue load comparison between two identical wind turbines employing different rotor designs. One turbine was fitted with a rotor consisting of a set of NREL (SERI) thin-airfoil blades while the other rotor included the original-equipment AeroStar blades. The data discussed are based on sample load populations derived from the rainflow cycle counting of 405, 10-minute records specifically collected over a wide range of inflow turbulence conditions. … more

Date: October 1, 1992

Creator: Kelley, N.; Desrochers, G.; Tangler, J. & Smith, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measured and predicted rotor performance for the SERI advanced wind turbine blades

Date: February 1, 1992

Creator: Tangler, J.; Smith, B.; Kelley, N. & Jager, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

An evaluation of an empirical model for stall delay due to rotation for HAWTS

The objective of this study was to evaluate the Corrigan and Schillings stall delay model for predicting rotor performance for horizontal axis wind turbines. Two-dimensional (2D) wind tunnel characteristics with and without stall delay were used in the computer program PROP93 to predict performance for the NREL Combined Experiment Rotor (CER) and a lower solidity commercial machine. For the CER, predictions were made with a constant-chord/twisted blade and a hypothetical tapered/twisted blade. … more

Date: July 1997

Creator: Tangler, J. L. & Selig, M. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Atmospheric performance of the special-purpose Solar Energy Research Institute (SERI) thin-airfoil family

The Solar Energy Research Institute (SERI), in cooperation with SeaWest Energy Group, has completed extensive atmospheric testing of the special-purpose SERI thin-airfoil family during the 1990 wind season. The purpose of this test program was to experimentally verify the predicted performance characteristics of the thin-airfoil family on a geometrically optimized blade, and to compare it to original-equipment blades under atmospheric wind conditions. The tests were run on two identical Micon 6… more

Date: September 1, 1990

Creator: Tangler, J.; Smith, B.; Jager, D. & Olsen, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Wind turbine design codes: A preliminary comparison of the aerodynamics

The National Wind Technology Center of the National Renewable Energy Laboratory is comparing several computer codes used to design and analyze wind turbines. The first part of this comparison is to determine how well the programs predict the aerodynamic behavior of turbines with no structural degrees of freedom. Without general agreement on the aerodynamics, it is futile to try to compare the structural response due to the aerodynamic input. In this paper, the authors compare the aerodynamic lo… more

Date: December 1, 1997

Creator: Buhl Jr., M. L.; Wright, A. D. & Tangler, J. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Blade Design Trade-Offs Using Low-Lift Airfoils for Stall-Regulated HAWTs

A systematic blade design study was conducted to explore the trade-offs in using low-lift airfoils for a 750-kilowatt stall-regulated wind turbine. Tip-region airfoils having a maximum lift coefficient ranging from 0.7-1.2 were considered in this study, with the main objective of identifying the practical lower limit for the maximum lift coefficient. Blades were optimized for both maximum annual energy production and minimum cost of energy using a method that takes into account aerodynamic and … more

Date: April 8, 1999

Creator: Giguere, P.; Selig, M. S. (University of Illinois at Urbana-Champaign) & Tangler, J. L. (National Renewable Energy Laboratory)

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Long-term simulation of turbulence-induced loads using the SNLWIND-3D, FAST, YawDyn, and ADAMS numerical codes

Notable progress was made in simulating the dynamic response of operating wind turbines during the past several years. In concert with these activities, the ability to adequately simulate the characteristics of the turbulent inflow, which is directly or indirectly responsible for much of the observed response, has also improved significantly. Recent investigations have shown that without such inflow simulations, it is often difficult to predict fatigue-load distributions that agree with observa… more

Date: October 1, 1996

Creator: Kelley, N. D.; Wright, A. D.; Buhl Jr., M. L. & Tangler, J. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Horizontal axis wind turbine post stall airfoil characteristics synthesization

Blade-element/momentum performance prediction codes are routinely used for wind turbine design and analysis. A weakness of these codes is their inability to consistently predict peak power upon which the machine structural design and cost are strongly dependent. The purpose of this study was to compare post-stall airfoil characteristics synthesization theory to a systematically acquired wind tunnel data set in which the effects of aspect ratio, airfoil thickness, and Reynolds number were invest… more

Date: June 1, 1991

Creator: Tangler, J.L. (Rockwell International Corp., Golden, CO (USA). Wind Energy Research Center) & Ostowari, C. (Texas A and M Univ., College Station, TX (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department