Quantitative Optical Analysis and Modelling of Short Circuits and Blow-Outs of Spark Channels under High-Velocity Flow Conditions

2018 ◽  
Author(s):  
Shogo Sayama ◽  
Masao Kinoshita ◽  
Yoshiyuki Mandokoro ◽  
Ryo Masuda ◽  
Takayuki Fuyuto
Keyword(s):  
High Velocity ◽  
Optical Analysis ◽  
Flow Conditions ◽  
High Velocity Flow ◽  
Velocity Flow ◽  
Short Circuits

Spark ignition and early flame development of lean mixtures under high-velocity flow conditions: An experimental study

2018 ◽  
Vol 20 (2) ◽  
pp. 236-246 ◽  
Author(s):  
Shogo Sayama ◽  
Masao Kinoshita ◽  
Yoshiyuki Mandokoro ◽  
Takayuki Fuyuto
Keyword(s):  
High Velocity ◽  
Spark Ignition ◽  
Ignition Energy ◽  
Flow Conditions ◽  
High Velocity Flow ◽  
Swirl Chamber ◽  
Spark Plug ◽  
Velocity Flow ◽  
Flame Development ◽  
Short Circuits

This study set out to experimentally investigate spark ignition and the subsequent early flame development of lean air–fuel mixtures of A/ F = 20–30 under high-velocity flow conditions using a uniquely designed swirl chamber. The swirl chamber realizes a high-velocity flow of 65 m/s at the spark plug gap, as well as internal temperature and pressure histories that are equivalent to those of spark-ignition engines, being equipped with an optically accessible engine. The designed swirl chamber clearly captures the characteristic behavior of the spark channels and flames in the vicinity of the spark plug. The results show that the spark channels stretch downstream following the flow and are subject to short circuits or restrikes. In the case of a high ignition energy of 200 mJ, short circuits of the spark channels occur in the early part of the discharge, while restrikes occur in the later parts. With a decrease in the ignition energy, restrikes occur in the earlier parts of the discharge. With a low ignition energy of 65 mJ, restrikes can occur immediately after the electrical breakdown without any significant spark stretch. At a sufficiently low dilution degree of A/ F = 20, flames can hold behind the ground electrode of the spark plug, which significantly suppresses the cycle dispersion while also enhancing the combustion in the early stage. With further air dilution, that is, A/ F > 20, flames develop, flowing downstream without flame holding. However, temporal flame attachment to the ground electrode is observed during the discharge duration even at A/ F = 30, while the attached flames eventually blow off downstream at the end of the spark discharge.

Direct measurement of bottom shear stress under high-velocity flow conditions

2016 ◽  
Vol 50 ◽  
pp. 121-127 ◽  
Author(s):  
Jae Hyeon Park ◽  
Young Do Kim ◽  
Yong Sung Park ◽  
Jae An Jo ◽  
Kimchhun Kang
Keyword(s):  
Shear Stress ◽  
Direct Measurement ◽  
High Velocity ◽  
Bottom Shear Stress ◽  
Flow Conditions ◽  
High Velocity Flow ◽  
Velocity Flow

ATOMIZATION CHARACTERISTICS OF LIQUID JETS INJECTED INTO A HIGH-VELOCITY FLOW FIELD

1994 ◽  
Vol 4 (4) ◽  
pp. 451-471 ◽  
Author(s):  
Nobuyuki Yatsuyanagi ◽  
Hiroshi Sakamoto ◽  
Kazuo Sato
Keyword(s):  
Flow Field ◽  
High Velocity ◽  
Liquid Jets ◽  
High Velocity Flow ◽  
Velocity Flow ◽  
Atomization Characteristics

SPECIFIC FEATURES OF DECELERATION OF A HIGH-VELOCITY FLOW IN CONVERGENT FIXED-GEOMETRY INLETS

2017 ◽  
Vol 48 (4) ◽  
pp. 341-355
Author(s):  
Vyacheslav Afanasievich Vinogradov ◽  
Natalya Valeryevna Guryleva ◽  
Mikhail Anatolyevich Ivan'kin ◽  
Vladimir Alekseevich Stepanov
Keyword(s):  
High Velocity ◽  
High Velocity Flow ◽  
Velocity Flow

Closure to “Ippen on High-Velocity Flow”

1951 ◽  
Vol 116 (1) ◽  
pp. 393-400
Author(s):  
Hunter Rouse ◽  
B. V. Bhoota ◽  
En-Yun Hsu
Keyword(s):  
High Velocity ◽  
High Velocity Flow ◽  
Velocity Flow
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