Experimental study on reflection coefficient of curved perforated plate

HHO merupakan gas hasil elektrolisa air yang dapat digunakan sebagai bahan bakar tambahan pada motor bakar. Penelitian ini bertujuan mengetahui karakteristik generator HHO menggunakan elektroda pelat berlubang. Elektroda yang dipakai berupa pelat aluminium dengan ukuran 60 x 60 x 0.5 mm3 dengan variasi tanpa lubang, 4 lubang, 6 lubang, dan 9 lubang. Masing-masing lubang berdiameter 4 mm. Variasi tegangan input 3,5; 6; 7,5; 9 Volt. Karakteristik yang diuji meliputi daya input, debit, dan efisiensi generator HHO. Hasil yang didapatkan dari penelitian ini adalah bahwa debit gas HHO yang terbesar dihasilkan dengan elektroda 9 lubang yaitu sebesar 5,77 cc/min dengan daya input 4,59 Watt. Sedangkan efisiensi generator tertinggi juga dihasilkan dengan elektroda 9 lubang yang mampu mencapai efisiensi 63,16 % dengan daya input 0,52 Watt.

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Experimental Study of Vortex Shedding From a Solid Sphere in Turbulent Freestream

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2005-77168 ◽

2005 ◽

Cited By ~ 2

Author(s):

Himanshu Tyagi ◽

Rui Liu ◽

David S.-K. Ting ◽

Clifton R. Johnston

Keyword(s):

Experimental Study ◽

Reynolds Number ◽

Flow Velocity ◽

Vortex Shedding ◽

Isotropic Turbulence ◽

Vortex Formation ◽

Perforated Plate ◽

Solid Sphere ◽

Mean Flow ◽

Static Pressure Distribution

The study of vortex shedding from a sphere assumes an important role because of its relevance to numerous aerodynamic and hydrodynamic applications. Parameters such as coefficient of drag and static pressure distribution are largely influenced by vortex shedding, and it is found by past studies that the freestream turbulence can interact and alter the vortex formation and shedding drastically. Most of these studies, however, were conducted in the low Reynolds number regime and the vortex shedding results had been described only qualitatively. To better understand the aerodynamics of a sphere in turbulent flow, an experimental study was initiated in a low speed wind tunnel to quantify the vortex shedding characteristics. The Reynolds number of the flow, based on the diameter of the sphere (d), was set at 3.3 × 104, 5 × 104 and 6.6 × 104 by varying the mean flow velocity. The sphere was placed at 20D (= 7.5d) downstream from a perforated plate, where D = 37.5 mm is the size of the holes in the perforated plate, uniquely designed for generating near-isotropic turbulence. Hot-wire measurements were taken at 10D (= 3.75d), 20D (= 7.5d) and 30D (= 11.25d) downstream of the sphere in absence and presence of the perforated plate. The vortex shedding frequency was deduced from the instantaneous flow velocity data.

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Study on the Effect of Porosity on the Reflection Coefficient and Wave Pressure on the Partially Perforated Plates

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.680.177 ◽

2013 ◽

Vol 680 ◽

pp. 177-182

Author(s):

Xue Feng Chen ◽

Mei Zhang

Keyword(s):

Reflection Coefficient ◽

Pressure Difference ◽

Mutual Influence ◽

Perforated Plate ◽

Numerical Results ◽

Internal Source ◽

Perforated Plates ◽

Numerical Wave Flume ◽

Wave Flume ◽

Sponge Layer

2D numerical wave flume is established based on the VOF method and k- model to numerically simulate the interaction of wave with perforated plates. The internal source generation of wave is applied in making wave area whose end is placed the sponge layer to absorb the reflection of wave. The numerical results of reflection coefficient before perforated plate are compared with the experimental results of reference (Liu, 2008) to verify the numerical method. By changing porosity, the effect of porosity on reflection coefficient can be analyzed. Moreover, the pressure difference between the outer and inner of perforated plate was studied, and then the mutual influence of porosity on the pressure difference is obtained according to the substantive numerical results.

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Experimental study on the acoustic field caused by the interference of supersonic jet with a perforated plate—The optical measurement of sound absorption

The Journal of the Acoustical Society of America ◽

10.1121/1.5137387 ◽

2019 ◽

Vol 146 (4) ◽

pp. 3000-3000

Author(s):

Yo Murata ◽

Kaku Murayama ◽

Tatsuya Ishii ◽

Koji Okamoto ◽

Hirofumi Daiguji ◽

...

Keyword(s):

Experimental Study ◽

Acoustic Field ◽

Sound Absorption ◽

Optical Measurement ◽

Supersonic Jet ◽

Perforated Plate

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Experimental Study of a Densely Perforated Plate Bending

Вестник Сибирского государственного университета путей сообщения ◽

10.52170/1815-9265_2021_57_99 ◽

2021 ◽

pp. 99-105

Author(s):

A. M. Popov ◽

V. B. Zinoviev ◽

S. I. Gerasimov ◽

L. A. Spodareva

Keyword(s):

Experimental Study ◽

Perforated Plate ◽

Plate Bending

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Experimental Study on Microwave Test of Cold Weld Defects in HDPE Piping Thermal Fusion Welds

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.433-435.895 ◽

2013 ◽

Vol 433-435 ◽

pp. 895-899

Author(s):

Jin Ping Pan ◽

Xin Wei Zhu ◽

Lian Jiang Tan

Keyword(s):

Experimental Study ◽

Reflection Coefficient ◽

High Density Polyethylene ◽

Testing System ◽

Proper Position ◽

Frequency Sweep ◽

Microwave Technique ◽

Weld Defects ◽

Fusion Weld ◽

Fusion Welds

In this paper, an effective method for detecting the cold weld defects in the thermal fusion weld of high-density polyethylene (HDPE) pipeline based on microwave technique is proposed. Using a microwave testing system, HDPE piping welds were examined in a proper position by frequency sweep within the range of 9.3-9.9 GHz. At a frequency that was most sensitive to the cold weld defects, the measured reflection coefficient S11 exhibited significantly different values between the good weld and those containing cold weld defects. The readily detectable differences in S11 value make identification of the cold weld defects possible. This work provides a basis for inspection of defects in HDPE piping welds.

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