NDLI: An experimental study on turbulence modification in the near-wall boundary layer of a dilute gas-particle channel flow

Content Provider	Springer Nature Link
Author	Li, Jing Wang, Hanfeng Liu, Zhaohui Chen, Sheng Zheng, Chuguang
Copyright Year	2012
Abstract	Turbulence modifications of a dilute gas-particle flow are experimentally investigated in the lower boundary layer of a horizontal channel by means of a simultaneous two-phase PIV measurement technique. The measurements are conducted in the near-wall region with y + < 250 at Re τ (based on the wall friction velocity u τ and half channel height h) = 430. High spatial resolution and small interrogation window are used to minimize the PIV measurement uncertainty due to the velocity gradient near the wall. Polythene beads with the diameter of 60 μm (d p + = 1.71, normalized by the fluid kinematic viscosity ν and u τ) are used as dispersed phase, and three low mass loading ratios (Φ m ) ranging from 10−4 to 10−3 are tested. It is found that the addition of the particles noticeably modifies the mean velocity and turbulent intensities of the gas-phase, as well as the turbulence coherent structures, even at Φ m = 0.025 %. Particle inertia changes the viscous sublayer of the gas turbulence with a smaller thickness and a larger streamwise velocity gradient, which increases the peak value of the streamwise fluctuation velocity ( $$ u_{\text{rms}}^{ + } $$ ) of the gas-phase with its location shifting to the wall. Particle sedimentation increases the roughness of the bottom wall, which significantly increases the wall-normal fluctuation velocity ( $$ v_{\text{rms}}^{ + } $$ ) and Reynolds shear stress ( $$ - \langle u^{ \prime } v^{\prime } \rangle^{ + } $$ ) of the gas-phase in the inner region of the boundary layer (y + < 10). Under effect of particle–wall collision, the Q2 events (ejections) of the gas-phase are slightly increased by particles, while the Q4 events (sweeps) are obviously decreased. The spatial scale of the coherent structures near the wall shrinks remarkably with the presence of the particles, which may be attributed to the intensified crossing-trajectory effects due to particle saltation near the bottom wall. Meanwhile, the $$ v_{\text{rms}}^{ + } $$ and $$ - \langle u^{ \prime } v^{\prime } \rangle^{ + } $$ of the gas-phase are significantly reduced in the outer region of the boundary layer (y + > 20).
Starting Page	1385
Ending Page	1403
Page Count	19
File Format	PDF
ISSN	07234864
Journal	Experiments in Fluids
Volume Number	53
Issue Number	5
e-ISSN	14321114
Language	English
Publisher	Springer-Verlag
Publisher Date	2012-08-30
Publisher Place	Berlin, Heidelberg
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Engineering Fluid Dynamics Engineering Thermodynamics, Heat and Mass Transfer Fluid- and Aerodynamics
Content Type	Text
Resource Type	Article
Subject	Fluid Flow and Transfer Processes Physics and Astronomy Mechanics of Materials Computational Mechanics

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Turbulence in rough-wall boundary layers: universality issues

Stereo particle image velocimetry of nonequilibrium turbulence relaxation in a supersonic boundary layer

Flow characteristics around a wall-mounted spherical obstacle in a thin boundary layer

PIV experiments in rough-wall, laminar-to-turbulent, oscillatory boundary-layer flows

Boundary layer effect on the vortex shedding of wall-mounted rectangular cylinder

Whole-wavelength description of a wave boundary layer over permeable wall

Experimental detection of a periodically forced turbulent boundary layer separation

Near-wake flow structure downwind of a wind turbine in a turbulent boundary layer

Flow around two tandem square cylinders near a plane wall

An experimental study on turbulence modification in the near-wall boundary layer of a dilute gas-particle channel flow

Similar Documents

Turbulence in rough-wall boundary layers: universality issues

Stereo particle image velocimetry of nonequilibrium turbulence relaxation in a supersonic boundary layer

Flow characteristics around a wall-mounted spherical obstacle in a thin boundary layer

PIV experiments in rough-wall, laminar-to-turbulent, oscillatory boundary-layer flows

Boundary layer effect on the vortex shedding of wall-mounted rectangular cylinder

Whole-wavelength description of a wave boundary layer over permeable wall

Experimental detection of a periodically forced turbulent boundary layer separation

Near-wake flow structure downwind of a wind turbine in a turbulent boundary layer

Flow around two tandem square cylinders near a plane wall

An experimental study on turbulence modification in the near-wall boundary layer of a dilute gas-particle channel flow