scholarly journals Brief communication: Wind inflow observation from load harmonics – wind tunnel validation of the rotationally symmetric formulation

2019 ◽  
Vol 4 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Marta Bertelè ◽  
Carlo L. Bottasso ◽  
Stefano Cacciola
Keyword(s):  
Wind Tunnel ◽  
Turbine Rotor ◽  
Vertical Shear ◽  
Simulation Environment ◽  
Wind Model ◽  
Data Set ◽  
Rotationally Symmetric ◽  
Out Of Plane ◽  
Rotor Disk ◽  
Symmetric Formulation

Abstract. The present paper further develops and experimentally validates the previously published idea of estimating the wind inflow at a turbine rotor disk from the machine response. A linear model is formulated that relates one per revolution (1P) harmonics of the in- and out-of-plane blade root bending moments to four wind parameters, representing vertical and horizontal shears and misalignment angles. Improving on this concept, the present work exploits the rotationally symmetric behavior of the rotor in the formulation of the load-wind model. In a nutshell, this means that the effects on the loads of the vertical shear and misalignment are the same as those of the horizontal quantities, simply shifted by π∕2. This results in a simpler identification of the model, which needs a reduced set of observations. The performance of the proposed method is first tested in a simulation environment and then validated with an experimental data set obtained with an aeroelastically scaled turbine model in a boundary layer wind tunnel.

scholarly journals Wind inflow observation from load harmonics: wind tunnel validation of the rotationally symmetric formulation

2018 ◽  
Author(s):  
Marta Bertelè ◽  
Carlo L. Bottasso ◽  
Stefano Cacciola
Keyword(s):  
Wind Tunnel ◽  
Turbine Rotor ◽  
Vertical Shear ◽  
Simulation Environment ◽  
Wind Model ◽  
Data Set ◽  
Rotationally Symmetric ◽  
Out Of Plane ◽  
Rotor Disk ◽  
Symmetric Formulation

Abstract. The present paper further develops and experimentally validates the previously published idea of estimating the wind inflow at a turbine rotor disk from the machine response. A linear model is formulated that relates one per revolution (1P) harmonics of the in- and out-of-plane blade root bending moments to four wind parameters, representing vertical and horizontal shears and misalignment angles. Improving on this concept, the present work exploits the rotationally symmetric behaviour of the rotor in the formulation of the load-wind model. In a nutshell, this means that the effects on the loads of the vertical shear and misalignment are the same as those of the horizontal quantities, simply shifted by π / 2. This results in a simpler identification of the model, which needs a reduced set of observations. The performance of the proposed method is first tested in a simulation environment and then validated with an experimental data set obtained with an aeroelastically scaled turbine model in a boundary layer wind tunnel.

scholarly journals Field testing of a local wind inflow estimator and wake detector

2020 ◽  
Author(s):  
Johannes Schreiber ◽  
Carlo L. Bottasso ◽  
Marta Bertelè
Keyword(s):  
Vertical Wind Shear ◽  
Field Testing ◽  
Turbine Rotor ◽  
Vertical Shear ◽  
Local Wind ◽  
Data Set ◽  
Rotating Blade ◽  
Monitoring And Forecasting ◽  
Rotor Disk ◽  
The One

Abstract. This paper presents the field validation of a method to estimate the local wind speed on different sectors of a turbine rotor disk. Each rotating blade is used as a scanning sensor that, travelling across the rotor disk, samples the inflow. From the local speed estimates, the method can reconstruct the vertical wind shear and detect the presence and location on an impinging wake shed by an upstream wind turbine. Shear and wake awareness have multiple uses, from turbine and farm control to monitoring and forecasting. This validation study is conducted with an experimental data set obtained with two multi-MW wind turbines and a hub-tall met-mast. Practical and simple procedures are presented and demonstrated to correct for the possible miscalibration of sensors. Results indicate a very good correlation between the estimated vertical shear and the one measured by the met-mast. Additionally, the proposed method exhibits a remarkable ability to locate and track the motion of an impinging wake on an affected rotor.

scholarly journals Field testing of a local wind inflow estimator and wake detector

2020 ◽  
Vol 5 (3) ◽  
pp. 867-884
Author(s):  
Johannes Schreiber ◽  
Carlo L. Bottasso ◽  
Marta Bertelè
Keyword(s):  
Vertical Wind Shear ◽  
Field Testing ◽  
Turbine Rotor ◽  
Vertical Shear ◽  
Local Wind ◽  
Data Set ◽  
Rotating Blade ◽  
Monitoring And Forecasting ◽  
Rotor Disk ◽  
The One

Abstract. This paper presents the field validation of a method to estimate the local wind speed on different sectors of a turbine rotor disk. Each rotating blade is used as a scanning sensor that, traveling across the rotor disk, samples the inflow. From the local speed estimates, the method can reconstruct the vertical wind shear and detect the presence and location on an impinging wake shed by an upstream wind turbine. Shear and wake awareness have multiple uses, from turbine and farm control to monitoring and forecasting. This validation study is conducted with an experimental data set obtained with two multi-megawatt wind turbines and a hub-tall met mast. Practical and simple procedures are presented and demonstrated to correct for the possible miscalibration of sensors. Results indicate a very good correlation between the estimated vertical shear and the one measured by the met mast. Additionally, the proposed method exhibits a remarkable ability to locate and track the motion of an impinging wake on an affected rotor.

scholarly journals The biological effect of cage design corrected for reductions in spray penetration

2014 ◽  
Vol 54 (4) ◽  
pp. 395-400 ◽  
Author(s):  
Bradley Keith Fritz ◽  
Wesley Clint Hoffmann ◽  
Jane Annalise Sara Bonds ◽  
Keith Haas ◽  
Zbigniew Czaczyk
Keyword(s):  
Wind Tunnel ◽  
Biological Effect ◽  
Conversion Factor ◽  
Mortality Data ◽  
Data Set ◽  
Spray Penetration ◽  
Mosquito Mortality ◽  
Insect Mortality ◽  
Group Variation ◽  
Penetration Data

Abstract In-field measures of physical spray concentration do not tend to correlate well with caged insect mortality data. This is partly due to the reduced penetration of the spray into the cage. Spray penetration is hindered by the structure of the cage. Wind tunnel studies were conducted to investigate the accuracy of those calculations developed to correct for filtration levels in caged mosquito bioassays. Zenivex E20 (Etofenprox) was applied at rates ranging from an LD10 to an LD90. Three cage types were used, each with different penetration levels. The dose approaching the cage was converted to the dose entering the cage using cage penetration data from previous research. The penetration conversion factor returned a data set that directly correlated dose with mosquito mortality (R2 = = 0.918). The mortality percent was a function of the dose within the cage. The mesh type acted as a regulator. Although the conversion factor was effective, the differences between cages was not always significant due to within-group variation.

Probabilistic Analysis of Turbine Disc SCC Incubation and Propagation

2002 ◽  
Author(s):  
Tony C. T. Lam ◽  
Robert Dewey
Keyword(s):  
Growth Rate ◽  
Incubation Time ◽  
Chromium Content ◽  
Probabilistic Approach ◽  
Turbine Rotor ◽  
Time Data ◽  
Weld Repair ◽  
Low Pressure Turbine ◽  
Turbine Disc ◽  
Rotor Disk

Stress corrosion cracking (SCC) is a common problem found on aging low-pressure turbine (LP) rotors that operate in a wet/dry stream environment. While much has been published on the growth rate of SCC in turbine rotor-disk materials, incubation time is rarely addressed. Since no effective way has been demonstrated to prevent disk rim SCC from occurring other than to replace the damaged rim with a weld repair of higher chromium content, a better understanding of incubation time could provide operators with a means to treat SCC before cracks are large enough to start to grow. This paper discusses the critical mechanisms involved in the SCC incubation, process and describes a probabilistic approach to make meaningful assessments of incubation time. Data published for General Electric turbine rotors is used to test the model.

A Computer Analysis of Wind Turbine Blade Dynamic Loads

1986 ◽  
Vol 108 (1) ◽  
pp. 17-25 ◽  
Author(s):  
R. W. Thresher ◽  
A. D. Wright ◽  
E. L. Hershberg
Keyword(s):  
Wind Turbine ◽  
Equations Of Motion ◽  
Computer Code ◽  
Turbine Rotor ◽  
Flapping Motion ◽  
Turbine Rotor Blade ◽  
Loads Analysis ◽  
Rotor Disk ◽  
Equidistant Points ◽  
Blade Loads

The flapping motion of a single wind turbine rotor blade has been analyzed and equations describing the flapping motion have been developed. The analysis was constrained to allow only flapping motions for a cantilevered blade, and the equations of motion are linearized. A computer code, called FLAP (Force and Loads Analysis Program), to solve the equations of motion and compute the blade loads, has been completed and compared to measured loads for a 3-bladed downwind turbine with stiff blades. The results of the program are presented in tabulated form for equidistant points along the blade and equal azimuth angles around the rotor disk. The blade deflection, slope and velocity, flapwise shear and moment, edgewise shear and moment, blade tension, and blade torsion are given. The deterministic excitations considered in the analysis include wind shear, tower shadow, gravity, and a prescribed yaw motion.

Turbine Clashing Transient Analysis: Impact of Rotor Disk Stage Onto Static Vane Stage After Shaft Rupture

2008 ◽  
Author(s):  
Carlo Frola ◽  
Antonino Vassallo ◽  
Marco Degiovanni ◽  
Massimiliano Mattone
Keyword(s):  
Angular Velocity ◽  
Transient Analysis ◽  
Turbine Rotor ◽  
Aircraft Engines ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Impact Phenomena ◽  
Rotor Disk ◽  
Turbine Shaft ◽  
The Impact

Turbine shaft rupture is one of the most critical failures of aircraft engines. When rupture happens turbine work is no more equilibrated by compressor. By consequence the turbine rotor increases its angular velocity and moves axially downstream, leading to an impact between rotor and static parts. This impact may be used to limit angular velocity below the maximum admitted burst speed. On the other hand, the impact phenomena must be controlled in order to avoid that turbine components break into many damaging uncontrolled fragments. In this paper a complete transient analysis has been developed to evaluate the motion laws during these clashing phenomena. The impact dissipation coefficient, used into the motion laws, has been estimated by a non linear finite element analysis. An example of application of this methodology is also reported.

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