The Wall Effect on Ventilated Cavitating Flows in Closed Cavitation Tunnels

Chen, Xin; Lu, Cewu; Li, Jie; Pan, Zhan-cheng

doi:10.1016/s1001-6058(08)60095-5

Cited by 27 publications

(5 citation statements)

References 8 publications

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“…For the turbulence model, the RNG k − ε model was used to calculate air flow process because it agrees with the experimental results and shows reliability in automobile flow field calculation problems [34,35]. In the light of Pulliam and Zingg [36], the turbulent kinetic energy k and the turbulence dissipation rate ε are set based on Equations ( 7) and ( 8), where R represents additional source term caused by deformation rate, µ t represents turbulence viscosity, as calculated by Equation ( 9)…”

Section: Mathematical Modelmentioning

confidence: 73%

Assessing On-Road Emission Flow Pattern under Car-Following Induced Turbulence Using Computational Fluid Dynamics (CFD) Numerical Simulation

Shi

Sun

et al. 2019

Sustainability

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Research assessing on-road emission flow patterns from motor vehicles is essential in monitoring urban air quality, since it helps to mitigate atmospheric pollution levels. To reveal the influence of vehicle induced turbulence (VIT) caused by both front- and rear-vehicles on traffic exhaust and verify the applicability of the simplified line source emission model, a Computational Fluid Dynamics (CFD) numerical simulation was used to investigate the micro-scale vehicle pollutant flow patterns. The simulation results were examined through sensitivity analysis and compared with the field measured carbon monoxide (CO) concentration. Conclusions indicate that the vehicle induced turbulence caused by the airflow blocking effect of both front- and rear-vehicles impedes the diffusion of front-vehicle traffic exhaust, compared with that of the rear vehicle. The front-vehicle isosurface with the CO mass fraction of 0.0012 extended to 6.0 m behind the vehicle, while that of the rear-vehicle extends as far as 12.7 m. But for the entire motorcade, VIT is beneficial to the diffusion of pollutants in car-following situations. Meanwhile, within the range of 9 m behind the rear of the lagging vehicle lies a vehicle induced turbulence zone. Furthermore, the influence of vehicle induced turbulence on traffic exhaust flow pattern is obvious within a range of 1 m on both sides of the vehicle body, where the concentration gradient of on-road emission is larger and contains severe mechanical turbulence. As a result, in the large concentration gradient area of the pollutant flow field, which accounts for 99.85% of the total concentration gradient, using the line source models to represent the on-road emission might introduce considerable errors due to neglecting the influence of vehicle induced turbulence. Findings of this study may shed lights on predicting emission concentrations in multiple locations by selecting appropriate on-road emission source models.

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Section: Mathematical Modelmentioning

confidence: 73%

Assessing On-Road Emission Flow Pattern under Car-Following Induced Turbulence Using Computational Fluid Dynamics (CFD) Numerical Simulation

Shi

Sun

et al. 2019

Sustainability

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“…Sorensen, et al [5] presented a correction model for wall effect on rotors of wind turbines or propellers in wind tunnels and the validation was carried out by using RANS model coupling with actuator disc method. Chen, et al [6] established an isotropic mixture multiphase model to study the wall effect that was based on RANS equations. Watanabe, et al [7] analyzed the wall effect on the cavitation of propeller.…”

Section: Introductionmentioning

confidence: 99%

Numerical Prediction of Wall Effect on Propeller in Restricted Channel

Ren¹,

Wan²

2019

JAMP

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In restricted channel, the hydrodynamic performance of propeller is affected by the wall. In the present work, two cylindrical channels with different diameters being 1.8D and 5.0D are adopted to study the influence of wall on the hydrodynamic performance and wake field of the propeller model DTMB4119. The numerical simulations are carried out by the single-phase solver pim-pleDyMFoam in open source platform OpenFOAM. The Reynolds Averaged Navier-Stokes equations (RANS) are adopted to solve the flow field. The arbitrary mesh interface (AMI) method is used to simulate the rotation of propeller. The designed advance ratio, J = 0.833, is applied in all the computations. For the 5.0 D case, the predicted results of open water performance are in good agreement with experiment data. In restricted channel, the predicted results of thrust and torque coefficients are larger than the open water case. The pressure on the wall of restricted channel downstream increases and approaches the results in open water gradually. Due to the flux conservation, higher negative induced velocity is investigated in the flow field of the propeller in restricted channel.

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“…Ishida and Kimoto conducted experimental analysis of the behavior of a single cavitation bubble near a wall to examine cavitation bubbles near a solid boundary using a quite complex test facility [3,4]. Zhou and Chen conducted a comparative study of ventilated supercavity around models with different shapes between the near-wall area and infinite flow [5][6][7] to explore near-wall effect. Wind tunnel test and CFD simulation were also conducted.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Near-wall effect on cloud cavitating flow that surrounds an axisymmetric projectile using large eddy simulation with Cartesian cut-cell mesh method

Wang

Huang

et al. 2018

European Journal of Mechanics - B/Fluids

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Near-wall effect is important for cavitation of flow and vortex structures. These structures are commonly investigated in cavitation of tip-vortex leakage, but are rarely discussed in cloud cavitating flow. In this study, typical experiments and numerical simulation of cloud cavitating flow were conducted near a wall that surrounds an underwater axisymmetric projectile. The experimental observations of cavity development are consistent with numerical results and validate the method's accuracy. Changes in the cavity of the distal and near wall side differ throughout the entire evolution process. The cavity grows faster on the near wall side than on the distal side, whereas the re-entry jet inside the cavity moves slowly toward the shoulder of the model. The strong vortex around the projectile is non-axisymmetric because of the collapsing cavity, which may also affect the cruising stability.

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The Wall Effect on Ventilated Cavitating Flows in Closed Cavitation Tunnels

Cited by 27 publications

References 8 publications

Assessing On-Road Emission Flow Pattern under Car-Following Induced Turbulence Using Computational Fluid Dynamics (CFD) Numerical Simulation

Assessing On-Road Emission Flow Pattern under Car-Following Induced Turbulence Using Computational Fluid Dynamics (CFD) Numerical Simulation

Numerical Prediction of Wall Effect on Propeller in Restricted Channel

Analysis of Near-wall effect on cloud cavitating flow that surrounds an axisymmetric projectile using large eddy simulation with Cartesian cut-cell mesh method

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