The Influence of Swirl Ratio on Turbulent Flow Structure in a Motored HSDI Diesel Engine - A Combined Experimental and Numerical Study

2004 ◽  
Author(s):  
Paul C. Miles ◽  
Dae Choi ◽  
Marcus Megerle ◽  
Bret RempelEwert ◽  
Rolf D. Reitz ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Turbulent Flow ◽  
Flow Structure ◽  
Numerical Study ◽  
Swirl Ratio ◽  
Turbulent Flow Structure ◽  
Hsdi Diesel Engine

scholarly journals Bowl Geometry Effects on Turbulent Flow Structure in a Direct Injection Diesel Engine

2018 ◽  
Author(s):  
Stephen Busch ◽  
Kan Zha ◽  
Federico Perini ◽  
Rolf Reitz ◽  
Eric Kurtz ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Turbulent Flow ◽  
Flow Structure ◽  
Direct Injection ◽  
Direct Injection Diesel Engine ◽  
Turbulent Flow Structure ◽  
Geometry Effects

Heat Transfer and Turbulent Flow Structure in Channels With Miniature V-Shaped Rib-Dimple Hybrid Structures on One Wall

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Peng Zhang ◽  
Yu Rao ◽  
Yanlin Li ◽  
Bernhard Weigand
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Secondary Flow ◽  
Flow Structure ◽  
Pressure Loss ◽  
Numerical Study ◽  
Hybrid Structures ◽  
Numerical Computations ◽  
Turbulent Flow Structure ◽  
Near Wall

An experimental and numerical study has been conducted on heat transfer and turbulent flow structure in channels with novel hybrid structures with miniature V-shaped ribs and dimples on one wall. One miniature V-shaped rib was arranged immediately upstream each individual dimple to form the hybrid structure, which aims at inducing additional near-wall secondary flow interacting with the dimple vortex flow and further improving the heat transfer. Steady-state convective heat transfer experiments were done to obtain the heat transfer and pressure loss of the turbulent flow over the surfaces with the miniature V rib-dimples for the Reynolds numbers from 18,700 to 60,000. In addition, the turbulent flow structure in the V rib-dimpled channels has been predicted by carrying out numerical computations. The experimental results indicated that the overall heat transfer enhancement of the miniature V rib-dimpled channels can be increased by up to about 60.0% compared with the counterpart of the dimpled only channel, and by about 23.0% compared with the counterpart of the miniature V ribbed only channel. The miniature V ribs showed appreciable effects on the heat transfer and pressure loss characteristics for the turbulent flow over the V rib-dimpled surfaces. The numerical computations showed that the miniature V rib upstream each dimple produced strong near-wall downwashing secondary flow, which significantly changed the flow patterns and intensified the turbulent flow mixing inside and outside the dimple and above the surrounding wall. These unique near-wall flow characteristics generated a significant heat transfer improvement in both the magnitude and the uniformity.

scholarly journals Turbulent flow structure at a 90-degree open channel confluence: Accounting for the distortion of the shear layer

2016 ◽  
Vol 12 ◽  
pp. 130-147 ◽  
Author(s):  
Saiyu Yuan ◽  
Hongwu Tang ◽  
Yang Xiao ◽  
Xuehan Qiu ◽  
Huiming Zhang ◽  
...  
Keyword(s):  
Turbulent Flow ◽  
Shear Layer ◽  
Flow Structure ◽  
Open Channel ◽  
Turbulent Flow Structure ◽  
Channel Confluence

Turbulent flow structure at a discordant river confluence: Asymmetric jet dynamics with implications for channel morphology

2017 ◽  
Vol 122 (6) ◽  
pp. 1278-1293 ◽  
Author(s):  
Alexander N. Sukhodolov ◽  
Julian Krick ◽  
Tatiana A. Sukhodolova ◽  
Zhengyang Cheng ◽  
Bruce L. Rhoads ◽  
...  
Keyword(s):  
Turbulent Flow ◽  
Flow Structure ◽  
Channel Morphology ◽  
River Confluence ◽  
Turbulent Flow Structure

Turbulent characteristics of flow in the vicinity of mid-channel braid bar

2020 ◽  
Author(s):  
Mohammad Amir Khan ◽  
Nayan Sharma ◽  
MANISH PANDEY ◽  
Mohd Obaid Qamar
Keyword(s):  
Turbulent Flow ◽  
Flow Structure ◽  
Turbulent Intensity ◽  
Flow Area ◽  
Fluvial Processes ◽  
Relative Dominance ◽  
Turbulent Characteristics ◽  
Turbulent Flow Structure ◽  
The Impact ◽  
Channel Bar

The impact of a mid-channel bar on the turbulent flow structure has been investigated in this research. A new Dominance Function S_(i,H) is proposed in this study as a measure of the relative dominance of ejection and sweep events in turbulent flow structure. Occurrence of the kolk-boil phenomenon is observed due to interaction of ejection and sweep events.. A new parameter Movement Ratio is formulated in this study which is found to faithfully reflect the fluvial processes of sedimentation and scouring on the channel bed.. Acceleration of flow is seen to occur at adjoining regions close to the upstream end of the bar. Due to the presence of the bar, the flow area in its proximity decreases which has caused increment in the velocity at sections located near the upstream end of the mid-channel bar. For model runs with bars, a distinct bulge in the turbulent intensity graph is observed.

Sign in / Sign up

Export Citation Format

Share Document