scholarly journals Numerical and experimental study of flow structure and heat release distribution in a stratified swirl flame with high-speed PIV and OH* measurements

AIP Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 075311
Author(s):  
Sheng Meng ◽  
Shizhi Wu ◽  
Man Zhang
Keyword(s):  
Experimental Study ◽  
Heat Release ◽  
Flow Structure ◽  
High Speed ◽  
Swirl Flame

Experimental study on laminated glass responses of high-speed trains subject to windblown sand particles loading

2021 ◽  
Vol 300 ◽  
pp. 124332
Author(s):  
Gongxun Deng ◽  
Wen Ma ◽  
Yong Peng ◽  
Shiming Wang ◽  
Song Yao ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Laminated Glass ◽  
Windblown Sand ◽  
High Speed Trains ◽  
Sand Particles

scholarly journals Experimental Study on Dynamic Combustion Characteristics in Swirl-Stabilized Combustors

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1609
Author(s):  
Donghyun Hwang ◽  
Kyubok Ahn
Keyword(s):  
Experimental Study ◽  
Heat Release ◽  
Dynamic Pressure ◽  
Combustion Instability ◽  
Flame Structure ◽  
Pressure Sensors ◽  
Necessary Condition ◽  
Rayleigh Criterion ◽  
Pressure Oscillations ◽  
Geometric Conditions

An experimental study was performed to investigate the combustion instability characteristics of swirl-stabilized combustors. A premixed gas composed of ethylene and air was burned under various flow and geometric conditions. Experiments were conducted by changing the inlet mean velocity, equivalence ratio, swirler vane angle, and combustor length. Two dynamic pressure sensors, a hot-wire anemometer, and a photomultiplier tube were installed to detect the pressure oscillations, velocity perturbations, and heat release fluctuations in the inlet and combustion chambers, respectively. An ICCD camera was used to capture the time-averaged flame structure. The objective was to understand the relationship between combustion instability and the Rayleigh criterion/the flame structure. When combustion instability occurred, the pressure oscillations were in-phase with the heat release oscillations. Even if the Rayleigh criterion between the pressure and heat release oscillations was satisfied, stable combustion with low pressure fluctuations was possible. This was explained by analyzing the dynamic flow and combustion data. The root-mean-square value of the heat release fluctuations was observed to predict the combustion instability region better than that of the inlet velocity fluctuations. The bifurcation of the flame structure was a necessary condition for combustion instability in this combustor. The results shed new insight into combustion instability in swirl-stabilized combustors.

scholarly journals Experimental study of a flow structure in coplanar channels

2020 ◽  
Vol 1683 ◽  
pp. 022088
Author(s):  
V I Terekhov ◽  
A V Zolotukhin ◽  
I A Chohar
Keyword(s):  
Experimental Study ◽  
Flow Structure ◽  
Coplanar Channels

Experimental Study of Turbulent Macroinstabilities in an Agitated System with Axial High-Speed Impeller and with Radial Baffles

1996 ◽  
Vol 61 (6) ◽  
pp. 856-867 ◽  
Author(s):  
Oldřich Brůha ◽  
Ivan Fořt ◽  
Pavel Smolka ◽  
Milan Jahoda
Keyword(s):  
Experimental Study ◽  
Flow Field ◽  
High Speed ◽  
Experimental Results ◽  
Turbulent Regime ◽  
Frequency Of Occurrence ◽  
Visualization Method ◽  
Entire Flow

The frequency of turbulent macroinstability occurrence was measured in liquids agitated in a cylindrical baffled vessel. As it has been proved by preceding experimental results of the authors, the stochastic quantity with frequency of occurrence of 10-1 to 100 s-1 is concerned. By suitable choosing the viscosity of liquids and frequency of impeller revolutins, the region of Reynolds mixing numbers was covered from the pure laminar up to fully developed turbulent regime. In addition to the equipment making it possible to record automatically the macroinstability occurrence, also the visualization method and videorecording were employed. It enabled us to describe in more detail the form of entire flow field in the agitated system and its behaviour in connection with the macroinstability occurrence. It follows from the experiments made that under turbulent regime of flow of agitated liquids the frequency of turbulent macroinstability occurrence is the same as the frequency of the primary circulation of agitated liquid.

scholarly journals Study and Analysis of Anti Vibratory Passive and Active Methods Applied to Complex Mechanical System

2012 ◽  
Vol 7 (2) ◽  
Author(s):  
Cédric Lopez ◽  
François Malburet ◽  
André Barraco
Keyword(s):  
Experimental Study ◽  
Comparative Analysis ◽  
Mechanical System ◽  
High Speed ◽  
Test Bench ◽  
Minimization Method ◽  
Controlled System ◽  
Proper Frequency ◽  
Different Parts ◽  
Methods Of Control

This paper studies problematic of a mechanical system composed of different coupled parts submitted to a high speed shock and proposes analysis of anti vibratory passive and active methods based on an experimental and theoretical coupled approach. After a shock, different parts of the system oscillate. If one of them is excited at a particular frequency, such as its proper frequency, important oscillations appear and can lead to the deterioration of the system by introducing important stresses. In this paper, we propose an analysis in order to understand this kind of problem and what we can do to avoid it. Firstly, we discuss problematic and we expose the studied system. In a second time, we develop two approaches of modeling that allow us to understand the phenomenon by carrying out numerical simulations. Then cross checking of model is completed via experimental study on drop test bench. Passive minimization method of vibrations based on experimental and theoretical coupled approach is exposed. Finally, a comparative analysis of different methods of control and experimental results of controlled system are presented.

Effects of Cutting Parameters on Residual Stresses in High-Speed Milling of Ti-17

2013 ◽  
Vol 834-836 ◽  
pp. 861-865 ◽  
Author(s):  
Yong Shou Liang ◽  
Jun Xue Ren ◽  
Yuan Feng Luo ◽  
Ding Hua Zhang
Keyword(s):  
Experimental Study ◽  
Residual Stresses ◽  
High Speed ◽  
Experimental Parameter ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Single Factor ◽  
Cutting Depth ◽  
High Speed Milling ◽  
Parameter Ranges

An experimental study was conducted to determine cutting parameters of high-speed milling of Ti-17 according to their effects on residual stresses. First, three groups of single factor experiments were carried out to reveal the effects of cutting parameters on residual stresses. Then sensitivity models were established to evaluate the influence degrees of cutting parameters on residual stresses. After that, three criteria were proposed to determine cutting parameters from experimental parameter ranges. In the experiments, the cutting parameter ranges are recommended as [371.8, 406.8] m/min, [0.363, 0.412] mm and [0, 0.018] mm/z for cutting speed, cutting depth and feed per tooth, respectively.

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