scholarly journals Innovative Blade Trailing Edge Flap Design Concept using Flexible Torsion Bar and Worm Drive

2020 ◽  
Vol 1 (3) ◽  
pp. 101-106
Author(s):  
Kwangtae Ha
Keyword(s):  
Torsional Rigidity ◽  
Turbine Rotor ◽  
Worm Gear ◽  
Bending Rigidity ◽  
Trailing Edge ◽  
Turbine Rotor Blade ◽  
Gear Drive ◽  
Actuation System ◽  
Trailing Edge Flap ◽  
Torsion Bar

In this paper, a simple but effective trailing edge flap system was proposed. This preliminary concept uses a more practical and stable actuation system which consists of a motor-driven worm gear drive and flexible torsion bar. The flexible torsion bar is designed to be easily twisted while keeping bending rigidity as a sup-port and the worm gear drive not only provides a high torque to overcome aero-dynamic forces on the flap area and the torsional rigidity of the support bar, but also acts as a brake to avoid instability due to the high torsional flexibility of sup-port bar. A preliminary level design study was performed to show the applicability of the new trailing edge flap system for wind turbine rotor blade or helicopter blade.

Dynamics of a pneumatic artificial muscle actuation system driving a trailing edge flap

2014 ◽  
Vol 23 (9) ◽  
pp. 095014 ◽  
Author(s):  
Benjamin K S Woods ◽  
Curt S Kothera ◽  
Gang Wang ◽  
Norman M Wereley
Keyword(s):  
Artificial Muscle ◽  
Pneumatic Artificial Muscle ◽  
Trailing Edge ◽  
Actuation System ◽  
Trailing Edge Flap

Influence of Unsteady Wake With Trailing Edge Coolant Ejection on Turbine Blade Film Cooling

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Shiou-Jiuan Li ◽  
Akhilesh P. Rallabandi ◽  
Je-Chin Han
Keyword(s):  
Film Cooling ◽  
Surface Film ◽  
Turbine Rotor ◽  
Suction Surface ◽  
Trailing Edge ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Turbine Rotor Blade ◽  
Blowing Ratio ◽  
Unsteady Wake

Detailed film cooling effectiveness distributions along a modeled turbine rotor blade under the combined effects of an upstream trailing edge unsteady wake with coolant ejection are presented using the pressure sensitive paint (PSP) mass transfer analogy method. The experiment is conducted in a low speed wind tunnel facility with a five blade linear cascade. The exit Reynolds number based on the axial chord is 370,000. Unsteady wakes and trailing edge coolant jets are produced by a spoked wheel-type wake generator with hollow rods equipped with several coolant ejections from holes. The coolant-to-mainstream density ratios for both the blade and trailing edge coolant ejection range from 1.5 to 2.0 for simulating realistic engine conditions. Blade blowing ratio studies are 0.5 and 1.0 on the suction surface and 1.0 and 2.0 on the pressure surface. The trailing edge jet blowing ratio and Strouhal numbers are 1.0 and 0.12, respectively. The results show that the unsteady wake reduces the overall film cooling effectiveness. However, the unsteady wake with trailing edge coolant ejection enhances the overall effectiveness. The results also show that the overall filming cooling effectiveness increases by using heavier coolant for trailing edge ejection and for blade surface film cooling.

A comprehensive investigation of trailing edge damage in a wind turbine rotor blade

Wind Energy ◽  
2016 ◽  
Vol 19 (10) ◽  
pp. 1871-1888 ◽  
Author(s):  
Philipp Ulrich Haselbach ◽  
Martin Alexander Eder ◽  
Federico Belloni
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Turbine Rotor ◽  
Comprehensive Investigation ◽  
Trailing Edge ◽  
Turbine Rotor Blade ◽  
Edge Damage ◽  
Wind Turbine Rotor

Influence of Unsteady Wake With Trailing Edge Coolant Ejection on Turbine Blade Film Cooling

2011 ◽  
Author(s):  
Shiou-Jiuan Li ◽  
Akhilesh P. Rallabandi ◽  
Je-Chin Han
Keyword(s):  
Film Cooling ◽  
Surface Film ◽  
Turbine Rotor ◽  
Suction Surface ◽  
Trailing Edge ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Turbine Rotor Blade ◽  
Pressure Surface ◽  
Unsteady Wake

Detailed film cooling effectiveness distributions along a modeled turbine rotor blade under combined effects of upstream trailing edge unsteady wake with coolant ejection are presented using the pressure sensitive paint (PSP) mass transfer analogy method. The experiment is conducted in a low speed wind tunnel facility with a five blade linear cascade. The exit Reynolds number based on the axial chord is 370,000. Unsteady wakes and trailing edge coolant jets are produced by a spoked wheel-type wake generator with hollow rods equipped with several coolant ejections from holes. The coolant-to-mainstream density ratios for both blade and trailing edge coolant ejection range from 1.5 to 2.0 for simulating realistic engine conditions. Blade blowing ratios studied are 0.5 and 1.0 on Suction surface and 1.0 and 2.0 on Pressure surface. Trailing edge jet blowing ratio and Strouhal number are 1.0 and 0.12, respectively. Results show the unsteady wake reduces overall film cooling effectiveness. However, the unsteady wake with trailing edge coolant ejection enhances overall effectiveness. Results also show that the overall filming cooling effectiveness increases by using heavier coolant for trailing edge ejection as well as for blade surface film cooling.

Wind Tunnel Testing of a Helicopter Rotor Trailing Edge Flap Actuated via Pneumatic Artificial Muscles

2010 ◽  
Author(s):  
Benjamin K. S. Woods ◽  
Norman M. Wereley ◽  
Curt S. Kothera
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Load ◽  
Artificial Muscles ◽  
Specific Work ◽  
Test Model ◽  
Trailing Edge ◽  
Actuation System ◽  
Wide Range ◽  
Pneumatic Artificial Muscles ◽  
Trailing Edge Flap

A novel active trailing edge flap actuation system is under development. This system differs significantly from previous trailing edge flap systems in that it is driven by a pneumatic actuator technology. Pneumatic Artificial Muscles (PAMs) were chosen because of several attractive properties, including high specific work and power output, an expendable operating fluid, and robustness. The actuation system is sized for a full scale active rotor system for a Bell 407 scale helicopter. This system is designed to produce large flap deflections (±20°) at the main rotor rotation frequency (1/rev) to create large amplitude thrust variation for primary control of the helicopter. Additionally, it is designed to produce smaller magnitude deflections at higher frequencies, up to 5/rev (N+1/rev), to provide vibration mitigation capability. The basic configuration has a pair of Pneumatic Artificial Muscles mounted antagonistically in the root of each blade. A bellcrank and linkage system transfers the force and motion of these actuators to a trailing edge flap on the outboard portion of the rotor. A reduced span wind tunnel test model of this system has been built and tested in the Glenn L. Martin Wind Tunnel at the University of Maryland at wind speeds up to M = 0.3. The test article consisted of a 5-ft long tip section of a Bell 407 rotor blade cantilevered from the base of the tunnel with a 34 in, 15% chord plain flap that was driven by the PAM actuation system. Testing over a wide range of aerodynamic conditions and actuation parameters established the considerable control authority and bandwidth of the system at the aerodynamic load levels available in the tunnel. Comparison of quasi-static experimental results shows good agreement with predictions made using a simple system model.

Study of Film Cooling in the Trailing Edge Region of a Turbine Rotor Blade in High Speed Flow Using Pressure Sensitive Paint

2016 ◽  
Author(s):  
Niharika Gurram ◽  
Peter T. Ireland ◽  
Tsun Holt Wong ◽  
Kevin P. Self
Keyword(s):  
Film Cooling ◽  
Rotor Blade ◽  
High Speed ◽  
Turbine Rotor ◽  
Edge Region ◽  
Pressure Sensitive Paint ◽  
Trailing Edge ◽  
Turbine Rotor Blade ◽  
Blowing Ratio ◽  
Pressure Sensitive

This research focuses on film cooling of the trailing edge of a scaled up turbine rotor blade with engine-representative Mach number distribution. Pressure sensitive paint was used to obtain high-resolution adiabatic film cooling effectiveness measurements in the trailing edge region of the scaled turbine blade. The large scale, high-speed experimental set-up consists of a Perspex test section for maximum visibility of the PSP coated blade. The test section was designed to recreate a single blade passage of a gas turbine with inlet Mach and Reynolds numbers matching the corresponding values in an engine. The test blade has a constant cross section, representative of the mid-span profile of the high pressure turbine rotor blade. It was manufactured from aluminium to minimize temperature gradients over the surface of the test blade. In the current research, pressure surface cooling slots at the trailing edge were examined and the effect of cutback surface protuberance, or ‘land’, shapes on trailing edge film cooling was studied. Nitrogen and air were used as coolant gases giving a coolant to mainstream density ratio close to 1. Two land geometries-straight and tapered-were studied for a set of 6 blowing ratios from 0.4 to 1.4 in steps of 0.2. Land taper has a benefit for film cooling near the slot exit but its advantage reduces close to the trailing edge. For both geometries, film effectiveness falls with blowing ratio from 0.4 to 0.8 and increases with blowing ratio in the 0.8 to 1.4 range. Crossflow causes the coolant film to be biased towards one side of the lands. Film effectiveness results are compared with data from a scaled up low speed flat plat model of the trailing edge to explain the effect of acceleration on film cooling.

scholarly journals Performance and Effect of Load Mitigation of a Trailing-Edge Flap in a Large-Scale Offshore Wind Turbine

2020 ◽  
Vol 8 (2) ◽  
pp. 72 ◽  
Author(s):  
Xin Cai ◽  
Yazhou Wang ◽  
Bofeng Xu ◽  
Junheng Feng
Keyword(s):  
Wind Turbine ◽  
Load Distribution ◽  
Large Scale ◽  
Turbine Rotor ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Trailing Edge ◽  
Turbulent Wind ◽  
Offshore Wind Turbines ◽  
Trailing Edge Flap

As a result of the large-scale trend of offshore wind turbines, wind shear and turbulent wind conditions cause significant fluctuations of the wind turbine’s torque and thrust, which significantly affect the service life of the wind turbine gearbox and the power output stability. The use of a trailing-edge flap is proposed as a supplement to the pitch control to mitigate the load fluctuations of large-scale offshore wind turbines. A wind turbine rotor model with a trailing-edge flap is established by using the free vortex wake (FVW) model. The effects of the deflection angle of the trailing-edge flap on the load distribution of the blades and wake flow field of the offshore wind turbine are analyzed. The wind turbine load response under the control of the trailing-edge flap is obtained by simulating shear wind and turbulent wind conditions. The results show that a better control effect can be achieved in the high wind speed condition because the average angle of attack of the blade profile is small. The trailing-edge flap significantly changes the load distribution of the blade and the wake field and mitigates the low-frequency torque and thrust fluctuations of the turbine rotor under the action of wind shear and turbulent wind.

Prediction of Turbine Rotor Blade Forcing due to In-Service Stator Vane Trailing Edge Damage

2011 ◽  
Author(s):  
Marcus Meyer ◽  
Roland Parchem ◽  
Peter Davison
Keyword(s):  
Surrogate Model ◽  
Rotor Blade ◽  
Stokes Equations ◽  
Turbine Rotor ◽  
Forced Response ◽  
Navier Stokes ◽  
Special Focus ◽  
Trailing Edge ◽  
Material Loss ◽  
Turbine Rotor Blade

In the following paper we will present an overview on the results of a research project whose objective is the assessment of the influence of trailing edge material loss of high pressure turbine nozzle guide vanes onto the low engine order excitation of the downstream rotor blade. To quantify the forcing, the modal forces for the rotor eigenmodes of interest are obtained by solving the unsteady Navier-Stokes equations for a full assembly of stator and rotor ring. Since the computing resources for such a calculation are too high to be routinely employed for the assessment of in-service damage patterns, an important task of the project was to investigate quick alternatives to the costly CFD simulations. The approach chosen is to perform a sufficient number of forced response calculations with different damage patterns in advance and use the results to build a surrogate model that can be used to assess the severity of damage patterns by simple interpolation. We will first present the analysis chain employed to quantify the forcing, next describe the approach to build a surrogate model with special focus on the generation of an optimal DoE matrix, and finally discuss the prediction accuracy of the surrogate model. It is shown that an interpolating surrogate model, based on radial basis functions, can successfully be used to predict the rotor forcing for damage patterns that were not analyzed using the costly CFD calculations beforehand.

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