Comparison of a Blade Element Momentum Model to 3D CFD Simulations for Small Scale Propellers

2013 ◽  
Vol 6 (2) ◽  
pp. 721-726 ◽  
Author(s):  
Joseph Carroll ◽  
David Marcum
Keyword(s):  
Small Scale ◽  
Cfd Simulations ◽  
Blade Element

Wind Tunnel Tests of a Model Small-scale Horizontal-axis Wind Turbine Developed from Blade Element Momentum Theory

2021 ◽  
pp. 1-16
Author(s):  
Ojing Siram ◽  
Niranjan Sahoo ◽  
Ujjwal K. Saha
Keyword(s):  
Wind Tunnel ◽  
Horizontal Axis ◽  
Superior Performance ◽  
Speed Ratio ◽  
Small Scale ◽  
Blade Design ◽  
Horizontal Axis Wind Turbine ◽  
Blade Element Momentum Theory ◽  
Momentum Theory ◽  
Blade Element

Abstract The small-scale horizontal-axis wind turbines (SHAWTs) have emerged as the promising alternative energy resource for the off-grid electrical power generation. These turbines primarily operate at low Reynolds number, low wind speed, and low tip speed ratio conditions. Under such circumstances, the airfoil selection and blade design of a SHAWT becomes a challenging task. The present work puts forward the necessary steps starting from the aerofoil selection to the blade design and analysis by means of blade element momentum theory (BEMT) for the development of four model rotors composed of E216, SG6043, NACA63415, and NACA0012 airfoils. This analysis shows the superior performance of the model rotor with E216 airfoil in comparison to other three models. However, the subsequent wind tunnel study with the E216 model, a marginal drop in its performance due to mechanical losses has been observed.

scholarly journals Numerical CFD simulations on a small-scale ORC expander using a customized grid generation methodology

2017 ◽  
Vol 129 ◽  
pp. 843-850 ◽  
Author(s):  
Giuseppe Bianchi ◽  
Sham Rane ◽  
Ahmed Kovacevic ◽  
Roberto Cipollone ◽  
Stefano Murgia ◽  
...  
Keyword(s):  
Grid Generation ◽  
Small Scale ◽  
Cfd Simulations

Active vibration suppression of elastic blade structure: Using a novel magnetorheological layer patch

2018 ◽  
Vol 29 (19) ◽  
pp. 3792-3803 ◽  
Author(s):  
Fevzi Cakmak Bolat ◽  
Selim Sivrioglu
Keyword(s):  
Wind Turbine ◽  
Vibration Suppression ◽  
State Space Model ◽  
Interaction Model ◽  
Parametric Uncertainty ◽  
Small Scale ◽  
Aerodynamic Load ◽  
Active Vibration Suppression ◽  
Active Vibration ◽  
Blade Element

This research study proposes a new active control structure to suppress vibrations of a small-scale wind turbine blade with attached magnetorheological fluid patch actuated by an electromagnet. The blade structure is manufactured by an aluminum extrusion machine considering the airfoil data of SH3055 which is designed for use on a small wind turbine. An interaction model between the magnetorheological patch and the electromagnetic actuator is derived and a force characterization is realized. A norm-based multiobjective H2/ H∞ controller is designed using the state-space model of the elastic blade element. The H2/ H∞ controller is experimentally implemented under the steady-state aerodynamic load conditions. The results of experiments show that the magnetorheological layer patch is effective for suppressing vibrations of the blade structure and robust against parametric uncertainty.

scholarly journals Comparison of Blade Element Method and CFD Simulations of a 10 MW Wind Turbine

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 73 ◽  
Author(s):  
Galih Bangga
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Separation ◽  
Spatial Interpolation ◽  
Flow Conditions ◽  
Cfd Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Correction Terms ◽  
Selection Of ◽  
Blade Element

The present studies deliver the computational investigations of a 10 MW turbine with a diameter of 205.8 m developed within the framework of the AVATAR (Advanced Aerodynamic Tools for Large Rotors) project. The simulations were carried out using two methods with different fidelity levels, namely the computational fluid dynamics (CFD) and blade element and momentum (BEM) approaches. For this purpose, a new BEM code namely B-GO was developed employing several correction terms and three different polar and spatial interpolation options. Several flow conditions were considered in the simulations, ranging from the design condition to the off-design condition where massive flow separation takes place, challenging the validity of the BEM approach. An excellent agreement is obtained between the BEM computations and the 3D CFD results for all blade regions, even when massive flow separation occurs on the blade inboard area. The results demonstrate that the selection of the polar data can influence the accuracy of the BEM results significantly, where the 3D polar datasets extracted from the CFD simulations are considered the best. The BEM prediction depends on the interpolation order and the blade segment discretization.

Fully-Coupled Turbojet Engine CFD Simulations and Cycle Analyses Along the Equilibrium Running Line

2020 ◽  
Author(s):  
Alejandro Briones ◽  
Andrew W Caswell ◽  
Brent Rankin
Keyword(s):  
Flow Rate ◽  
Fluid Dynamic ◽  
Thermodynamic Cycle ◽  
Angular Speed ◽  
Small Scale ◽  
Cfd Simulations ◽  
Fuel Flow ◽  
Turbojet Engine ◽  
Design Cycle ◽  
Fully Coupled

Abstract This work presents fully-coupled computational fluid dynamic (CFD) simulations and thermodynamic cycle analyses of a small-scale turbojet engine at several conditions along the equilibrium running line. The CFD simulations use a single mesh for the entire engine, from the intake to the exhaust, allowing information to travel in all directions. The CFD simulations are performed along the equilibrium running line by using the iterative Secant method to compute the fuel flow rate required to match the compressor and turbine power. The freestream pressure and temperature and shaft angular speed are the only inputs needed for the CFD simulations. To evaluate the consistency of the CFD results with thermodynamic cycle results, outputs from the CFD simulations are prescribed as inputs to the cycle model. This approach enables on-design and off-design cycle calculations to be performed without requiring turbomachinery performance maps. In contrast, traditional off-design cycle analyses require either scaling, calculating, or measuring compressor and turbine maps with boundary condition assumptions. In addition, the CFD simulations and the cycle analyses are compared with measurements of the turbojet engine. The CFD simulations, thermodynamic cycle analyses, and measurements agree in terms of total temperature and pressure at the diffuser-combustor interface, air and fuel mass flow rate, equivalence ratio, and thrust. The developed methods to perform CFD simulations from the intake to the exhaust of the turbojet engine are expected to be useful for guiding the design and development of future small-scale gas turbine engines.

A Theoretical and Experimental Comparison of Optimizing Angle of Twist Using BET and BEMT

2012 ◽  
Author(s):  
Timothy A. Burdett ◽  
Kenneth W. Van Treuren
Keyword(s):  
Experimental Testing ◽  
Element Model ◽  
Experimental Comparison ◽  
Speed Ratio ◽  
Small Scale ◽  
Blade Element Theory ◽  
Wind Speeds ◽  
Subsonic Wind Tunnel ◽  
Element Theory ◽  
Blade Element

Wind turbines are often designed using some form of Blade Element Model (BEM). However, different models can produce significantly different results when optimizing the angle of twist for power production. This paper compares the theoretical result of optimizing the angle of twist using Blade Element Theory (BET) and Blade Element Momentum Theory (BEMT) with a tip-loss correction for a 3-bladed, 1.15-m diameter wind turbine with a design tip speed ratio (TSR) of 5. These two theories have been chosen because they are readily available to small-scale designers. Additionally, the turbine was scaled for experimental testing in the Baylor Subsonic Wind Tunnel. Angle of twist distributions differed by as much as 15 degrees near the hub, and the coefficient of power differed as much as 0.08 for the wind speeds tested.

Development of Efficient Small Scale Axial Turbine for Solar Driven Organic Rankine Cycle

2016 ◽  
Author(s):  
Ayad Al Jubori ◽  
Raya K. Al-Dadah ◽  
Saad Mahmoud ◽  
Khalil M. Khalil ◽  
A. S. Bahr Ennil
Keyword(s):  
Large Scale ◽  
Renewable Energy Sources ◽  
Cycle Performance ◽  
Working Fluid ◽  
Small Scale ◽  
Cfd Simulations ◽  
Axial Turbine ◽  
Working Fluids ◽  
Wide Range ◽  
Inlet Conditions

Recently, the increase in fossil fuel consumption and associated adverse impact on the environment led to significant interest in renewable energy sources like solar. This paper presents a new methodology that integrates the ORC cycle analysis with modeling of an efficient small scale subsonic axial turbine at low temperature heat sources using wide range of organic working fluids like R123, R134a, R141b, R152a, R245fa, R290 and isobutene. The work involves detailed turbine analysis including 1D mean line approach, extensive 3D CFD simulations and ORC cycle analysis at inlet total pressure ranging from 2–5 bar corresponding to temperature range from 275K–365K to achieve the best turbine and cycle performance. This work provides a more reliable data base for small scale organic working fluids instead of using the map of large scale gas turbine. The numerical simulation was performed using 3D RANS with SST turbulence model in ANSYS-CFX. Using iterative CFD simulations with various working fluids with subsonic inlet conditions, Mach number ranging from 0.6–0.65, results showed that using working fluid R123 for a turbine with mean diameter of 70mm, the maximum isentropic efficiency was 82% and power output 5.66 kW leading to cycle efficiency of 9.5%.

Implementation of Computational Methods to Obtain Accurate Induction Factors for Offshore Wind Turbines

2014 ◽  
Author(s):  
Anand Bahuguni ◽  
Krishnamoorthi Sivalingam ◽  
Peter Davies ◽  
Johan Gullman-Strand ◽  
Vinh Tan Nguyen
Keyword(s):  
Wind Turbines ◽  
Lift Coefficient ◽  
Offshore Wind ◽  
Cfd Simulations ◽  
Sea State ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
Blade Tip ◽  
Computational Fluid Dynamics Cfd ◽  
Blade Element

Most of the wind turbine analysis softwares widely being used in the market are based on the Blade Element Momentum method (BEM). The two important parameters that the BEM codes calculate are the axial and the tangential induction factors. These factors are calculated based on the empirical blade lift coefficient Cl and drag coefficient Cd along with some loss/correction functions to account for the losses near the blade tip and the hub. The current study focusses on verifying the values of induction factors using Computational Fluid Dynamics (CFD) simulations for floating offshore wind turbines at a selected sea state. The study includes steady state calculations as well as transient calculations for pitching motions of the turbine due to waves. The NREL FAST software is used to set the simulation scenarios according to OC3 Phase IV cases. The blades are divided a number of elements in CFD calculations and the data are extracted at individual elements to have an exact comparison with the BEM based calculations.

A Study of Power Production and Noise Generation of a Small Wind Turbine for an Urban Environment

2017 ◽  
Author(s):  
Andrew Hays ◽  
Kenneth Van Treuren
Keyword(s):  
Urban Environment ◽  
Wind Turbines ◽  
Turbine Blades ◽  
Power Production ◽  
Small Scale ◽  
Momentum Theory ◽  
Small Wind Turbines ◽  
Noise Measurements ◽  
Utility Scale ◽  
Blade Element

Wind energy has had a major impact on the generation of renewable energy. While most research and development focuses on large, utility-scale wind turbines, a new application is in the field of small wind turbines in the urban environment. A major design challenge for these urban wind turbines is the noise generated during operation. This study examines the power production and the noise generated by two small-scale wind turbines tested in a small wind tunnel. Both rotors were designed using the Blade-Element Momentum Theory and either the NREL S823 or the Eppler 216 airfoils. Point noise measurements were taken using a 1/4” microphone at three locations downstream of the turbine: 16% of the diameter (two chord lengths), 50% of the diameter, and 75% of the diameter. At each horizontal location downstream of the turbine, a vertical traverse was performed to analyze the sound pressure level from the tip of the turbine blades down to the hub. The rotor designed with the Eppler 216 airfoil showed a 9% increase in power production and decrease of up to 7 dB(A).

scholarly journals Numerical analysis on the performance of Dual Rotor wind turbine

2020 ◽  
Vol 8 (03) ◽  
pp. 352-368
Author(s):  
Hazem Ali Abdel Karim ◽  
Ahmed Reda El-Baz ◽  
Nabil Abdel Aziz Mahmoud ◽  
Ashraf Mostafa Hamed
Keyword(s):  
Wind Turbine ◽  
Rotational Speed ◽  
Pitch Angle ◽  
Numerical Study ◽  
Three Dimensional ◽  
Scale Model ◽  
Power Coefficient ◽  
Peak Performance ◽  
Small Scale ◽  
Cfd Simulations

This study investigates the aerodynamic performance of wind turbines aiming to maximize the power extracted from the wind. The study is focusing on the effect of introducing a second rotor to the main rotor of the wind turbine in what is called a dual rotor wind turbine (DRWT).  The numerical study took place on the performance of small-scale model of wind turbine of 0.9 m diameter using S826 airfoil. Both the Co-rotating and Counter rotating configurations were investigated at different tip speed ratios (TSR) and compared with the performance of the single rotor wind turbine (SRWT). Many parameters were studied for dual rotor turbines. These include the spacing between the two rotors, the pitch angle of the rear rotor and the rotational speed of ratio rear to front rotor. Three-dimensional simulations performed and employed using CFD simulations with Multi Reference Frame (MRF) technique. The Co Rotating Wind Turbine (CWT) and Counter Rotating Wind Turbine (CRWT) found to have better performance compared to that of the SRWT with an increase ranging from 12 to 14% in peak power coefficient. Moreover, the effect of changing the pitch angle of the rear rotor on the overall performance found to be of a negligible effect between angles 0⁰ until 2⁰ degrees tilting toward the front rotor. On the other hand, the ratio of rotational speed of the rear rotor to the front rotor found to cause a further increase in the peak performance of the CWT and CRWT ranging from 3 to 5%.

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