scholarly journals PENELITIAN DAN RANCANGAN OPTIMAL TURBIN PENGGERAK TEROWONGAN ANGIN SUBSONIK SIRKUIT TERBUKA LAPAN

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Sulistyo Atmadi

In an effort to improve flow condition and flow speed up to 50 m per s inside LAPAN Subsonic Wind Tunnel, an existing power system and turbine has to be redesigned. Specifications for these requirments have been determined and calculated for the required power and aerofoil type and their dimensions. A method based free vortex design was used to get optimal result. The optimization result produced a turbine with 3 m diameter, with 10 blades, 1.5 m hub diameter. A D RAF PROPELLER aerofoil type was used to produce 230 HP power and 1824 Nm torque, with an efficience 89 percent. This result was considered both technically and economically.

Author(s):  
Srikanth G, ◽  
Surendra Bogadi

An extensive experimental study is conducted to examine the potentiality of Multi-Winglets (similar to bird tip feathers) for the reduction of Induced Drag, improved CL without increase in span of aircraft wing. The model composed of a rectangular wing built from NACA 0015 airfoil constituted of three winglets, which are small wings without sweep & twist. The test conducted in subsonic wind tunnel at flow speed 20m/s and placing the wing at angle of attack ranging from -5 to +15 deg. And also the wing with no winglet (bare wing) and with single winglet also tested in the same condition as in the case of three winglets (multi-winglet). Wind tunnel balances provided lift measurements and tuft flow visualization obtained wingtip vortex information. The results show that multi-winglet system reduced induced drag by 27.9% and improved CL by 26.5% compare to bare wing.


Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2682 ◽  
Author(s):  
Guang-Hui Ding ◽  
Bing-He Ma ◽  
Jin-Jun Deng ◽  
Wei-Zheng Yuan ◽  
Kang Liu

A micro-floating element wall shear stress sensor with backside connections has been developed for accurate measurements of wall shear stress under the turbulent boundary layer. The micro-sensor was designed and fabricated on a 10.16 cm SOI (Silicon on Insulator) wafer by MEMS (Micro-Electro-Mechanical System) processing technology. Then, it was calibrated by a wind tunnel setup over a range of 0 Pa to 65 Pa. The measurements of wall shear stress on a smooth plate were carried out in a 0.6 m × 0.6 m transonic wind tunnel. Flow speed ranges from 0.4 Ma to 0.8 Ma, with a corresponding Reynold number of 1.05 × 106~1.55 × 106 at the micro-sensor location. Wall shear stress measured by the micro-sensor has a range of about 34 Pa to 93 Pa, which is consistent with theoretical values. For comparisons, a Preston tube was also used to measure wall shear stress at the same time. The results show that wall shear stress obtained by three methods (the micro-sensor, a Preston tube, and theoretical results) are well agreed with each other.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Michał Lipian ◽  
Maciej Karczewski ◽  
Krzysztof Olasek

AbstractThe Diffuser Augmented Wind Turbine (DAWT) is an innovative mean to increase the power harvested by wind turbine. By encompassing the rotor with a diffusershaped duct it is possible to increase the flow speed through the turbine by about 40-50%. The study presents the development of a numerical model and its validation by the experiments performed in the wind tunnel of the Institute of Turbomachinery, TUL. Then, the numerical model is used for the geometry sensitivity study to optimize the shape of a diffuser. The paper presents that the DAWT technology has the potential to even double the power outcome of wind turbine when compared to a bare rotor version.


2014 ◽  
Vol 960-961 ◽  
pp. 1029-1033
Author(s):  
Yong Chun Su ◽  
Kai Xuan Chang

In order to face the challenge of our economy and the environment, it is needed to speed up the energy structure transition and UItra High voltage (UHV) transmission has become an inevitable choice. Researches on the influence of UHV project to Jiangxi power grid are carried out in this paper. Using advanced digital power system simulator (ADPSS), the real-time simulation model of Jiangxi power grid is build up including the UHV project. Based on the simulation model, the problem of low frequency oscillation in Jiangxi power system is studied after the UHV power transmission project accessed. The influence of the UHV transmission line faults on system stability of Jiangxi grid is also researched.


2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Agus Aribowo

This paper presents the results of investigation the separation buble which growing and burst on aerofoil NACA 0017 with effect mechanism of stall in the subsonic wind tunnel. Experiment have done on wind speed 20 m per s and 30 m per s. The data pecked from the orifice of pressure with interval 2 degree until stall position. The result was separation buble which growing on the airfoil, going to ahead of airfoil together with increasing the Reynolds number. After touching, the flow appeared to separate from the upper airfoil without reattachment.


1995 ◽  
Vol 32 (1) ◽  
pp. 199-204 ◽  
Author(s):  
Michael B. Bragg ◽  
Abdollah Khodadoust

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