High-Speed Particle Image Velocimetry Measurement of Partially Premixed Combustion (PPC) in a Light Duty Engine for Different Injection Strategies

2015 ◽  
Author(s):  
Zhenkan Wang ◽  
Slavey Tanov ◽  
Hua Wang ◽  
Mattias Richter ◽  
Bengt Johansson ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image Velocimetry Measurement ◽  
High Speed ◽  
Particle Image ◽  
Premixed Combustion ◽  
Light Duty ◽  
Partially Premixed Combustion ◽  
Image Velocimetry ◽  
Partially Premixed ◽  
Injection Strategies

Partially premixed combustion based on different injection strategies in a light-duty diesel engine

Energy ◽  
2016 ◽  
Vol 96 ◽  
pp. 155-165 ◽  
Author(s):  
Liang Qiu ◽  
Xiaobei Cheng ◽  
Bei Liu ◽  
Shijun Dong ◽  
Zufeng Bao
Keyword(s):  
Diesel Engine ◽  
Premixed Combustion ◽  
Light Duty ◽  
Partially Premixed Combustion ◽  
Partially Premixed ◽  
Injection Strategies

Experimental Investigation of the Transition Mechanism From Stable Flame to Flashback in a Generic Premixed Combustion System With High-Speed Micro-Particle Image Velocimetry and Micro-PLIF Combined With Chemiluminescence Imaging

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Georg Baumgartner ◽  
Lorenz R. Boeck ◽  
Thomas Sattelmayer
Keyword(s):  
Particle Image Velocimetry ◽  
Gas Turbines ◽  
High Speed ◽  
Particle Image ◽  
Premixed Combustion ◽  
Pollutant Emissions ◽  
Combustion System ◽  
Long Distance ◽  
Image Velocimetry ◽  
Stable Flame

Sustainable power generation resulting in low pollutant emissions, such as CO2 and NOx, poses a very challenging task in the near future. Premixed combustion of hydrogen-rich fuels in gas turbines is a promising approach to cope with ever more stringent regulations on emission levels. This method, however, involves the risk of flame flashback from the desired flame position into the premixing section, leading to catastrophic failure of the machine components that are not designed for such high temperatures. The objective of the current study was to visualize and describe the transition from stable flame to flashback in a generic H2–air combustion system and develop a physics-based model for the description of the transition. In order to achieve the high temporal and spatial resolution required for capturing the involved effects, high-speed particle image velocimetry (PIV) and high-speed planar laser-induced fluorescence (PLIF) were employed. In order to characterize the interaction of the flame with the flow in detail, both measurement techniques were applied to very small fields-of-view using (UV) long-distance microscopes. The repetition rates were 20 kHz for PLIF and 3 kHz for PIV, respectively. During both the PLIF and the PIV measurements, the flame's OH*-chemiluminescence was captured from a perspective perpendicular to that of the PLIF/PIV camera for further flame characterization. The microscopic measurements revealed that there is a negligible influence of the unconfined flame on the incoming burner flow in stable mode. Upon approaching the flashback conditions, however, the velocity profile of the burner flow is distinctly distorted by the presence of the flame inside the premixing duct. The flow directly upstream of the flame is retarded and deflected around the leading flame tip. Based on the effects observed in the experiments, a new flashback model is proposed, which identifies the heat transfer to the burner rim and the flame speed as the main drivers for the onset of flashback, whereas the flame backpressure is the governing factor for the subsequent upstream flame propagation.

scholarly journals Aerodynamics of manoeuvring flight in brown long-eared bats ( Plecotus auritus )

2018 ◽  
Vol 15 (148) ◽  
pp. 20180441 ◽  
Author(s):  
Per Henningsson ◽  
Lasse Jakobsen ◽  
Anders Hedenström
Keyword(s):  
Particle Image Velocimetry ◽  
Wind Tunnel ◽  
High Speed ◽  
Particle Image ◽  
Future Studies ◽  
Image Velocimetry ◽  
Mechanistic Basis

In this study, we explicitly examine the aerodynamics of manoeuvring flight in animals. We studied brown long-eared bats flying in a wind tunnel while performing basic sideways manoeuvres. We used particle image velocimetry in combination with high-speed filming to link aerodynamics and kinematics to understand the mechanistic basis of manoeuvres. We predicted that the bats would primarily use the downstroke to generate the asymmetries for the manoeuvre since it has been shown previously that the majority of forces are generated during this phase of the wingbeat. We found instead that the bats more often used the upstroke than they used the downstroke for this. We also found that the bats used both drag/thrust-based and lift-based asymmetries to perform the manoeuvre and that they even frequently switch between these within the course of a manoeuvre. We conclude that the bats used three main modes: lift asymmetries during downstroke, thrust/drag asymmetries during downstroke and thrust/drag asymmetries during upstroke. For future studies, we hypothesize that lift asymmetries are used for fast turns and thrust/drag for slow turns and that the choice between up- and downstroke depends on the timing of when the bat needs to generate asymmetries.

scholarly journals Dual-camera system for high-speed imaging in particle image velocimetry

2012 ◽  
Vol 15 (3) ◽  
pp. 193-195 ◽  
Author(s):  
K. Hashimoto ◽  
A. Hori ◽  
T. Hara ◽  
S. Onogi ◽  
H. Mouri
Keyword(s):  
Particle Image Velocimetry ◽  
High Speed ◽  
Particle Image ◽  
High Speed Imaging ◽  
Camera System ◽  
Image Velocimetry
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