Jiayue Hu - Academia.edu (original) (raw)

Papers by Jiayue Hu

With the continuous development of Computational Fluid Dynamics (CFD), many different numerical m... more With the continuous development of Computational Fluid Dynamics (CFD), many different numerical methods and turbulence models have been modified to enhance the capability of prediction of complex turbulence flow. This study investigates the characteristics of the shock wave-boundary layer interactions (SWBLI) generated by the fin with an angle of attack of 15°in a Mach 2 flow. Reynolds-averaged Navier-Stokes equations (RANS) are employed in this research with two different turbulence closures, which are Wilcox k  -Model and Blended , kk  -- Turbulence Model, using TENASI as the CFD solver. The simulation results are compared with the data from wind tunnel experiments using the Plenoptic PIV method so that the performance and limitations of different turbulence models could be estimated. The simulation of the fin tested in the same flow condition but in a non-obstacle surrounding is also introduced to show the difference of the supersonic flow field between the in-tunnel case and the free stream case. iii Dedication To my love, Xinlian.

Near-Full-Scale Hydraulic Modeling of Fish-Friendly Culvert with Full-Height Sidewall Baffles

Journal of hydraulic engineering, Jul 1, 2024

The adoption of baffles is relatively common in the construction of culverts, to assist with the ... more The adoption of baffles is relatively common in the construction of culverts, to assist with the upstream passage of migrating fish species. However, there still is a lack of systematic studies of the complicated hydraulic conditions induced by the baffles to optimize the designs. Herein, near-full-scale physical modeling was performed, focusing on the oscillation and instability of open-channel flow in a fishfriendly culvert equipped with full-height sidewall baffles. High-resolution measurements of the instantaneous flow velocity were obtained using an acoustic Doppler velocimeter. The physical results were marked by the existence of some low-frequency oscillations. A triple decomposition technique was applied to the free-surface and velocity time series. The low-pass components confirmed a unique flow structure, consisting of a high-velocity zone in the main channel and a low-velocity flow reversal within the lateral cavities. The band-pass components corresponded to the low-frequency flow oscillations, highlighting the complicated transverse interactions between the lateral cavity and the main channel. The high-pass velocity components were related to the true turbulence characteristics. This study provides a quantitative data set in support of the sustainable design of culverts to assist with upstream fish migration in artificial and natural fast waterways.

Environmental Fluid Mechanics, 24:465–488, 2024

For the last five decades, a number of overflow stepped chutes were built because the staircase s... more For the last five decades, a number of overflow stepped chutes were built because the staircase shape is conducive to reduced construction costs and increased rate of energy dissipation. The stepped chute operations are characterised by air-water flows that are highly turbulent flows with a large rate of energy dissipation, in comparison to smooth chutes. Herein, physical measurements were performed in a large-size 1 V: 0.80H stepped chute model, with a steep slope typical of modern concrete gravity dams. The results are compared to visual observations of prototype spillway operation under Froude similar conditions. The detailed two-phase flow measurements were conducted to characterise finely the self-aeration and air diffusion process downstream of the inception region of free-surface aeration. The bubble count rate profiles scaled with the instantaneous void fraction variance, and the relationship was biased close to the stepped invert under the influence of large-scale vortical structures. The rate of energy dissipation was carefully estimated based upon the two-phase flow measurements and the results are compared to earlier results on similar steep invert slopes and prototype data estimates. At the downstream end of the stepped chute, the rate of energy dissipation ranged from 43 to 46%, i.e. more than twice that on a smooth-invert chute for a similar chute length and discharge range.

Proceedings of the 10th International Symposium on Hydraulic Structures 2024 – 10th ISHS, 17-19 June, 2024

For the last decades, a number of overflow stepped spillways were built because the staircase sha... more For the last decades, a number of overflow stepped spillways were built because the staircase shape is conducive to reduced construction costs and increased rate of energy dissipation. Stepped spillways are characterised by highly turbulent air􀰆 water flows and a significantly larger rate of energy dissipation compared to smooth chutes. Herein, detailed measurements were performed in a large􀰆size 1V:0.8H stepped spillway model and complemented with 1V:0.8H stepped spillway prototype data. The steep slope is typical of modern concrete gravity dams. The laboratory facility was a 15:1 scale model of the large dam's stepped spillway where field observations were conducted between 2013 and 2024. Froude similar experiments were conducted based upon the 2021 flood conditions and detailed two􀰆phase flow measurements were undertaken to characterise finely the self􀰆aeration and rate of energy dissipation. The hybrid modelling Mark II combined physical and field measurements and it delivered herein a composite approach yielding some robust estimates directly relevant to design engineers

31st Hydrology and Water Resources Symposium HWRS2023, Sydney, Australia, 12-15 November, Published by Engineers Australia, pp. 11-20 (ISBN 978-1-925627-81-7)., 2023

During the last five decades, a number of overflow stepped spillways were built because the stair... more During the last five decades, a number of overflow stepped spillways were built because the staircase bywash shape is conducive to reduced construction costs and increase rate of energy dissipation. Stepped spillways are characterised by highly turbulent air-water flows and a large rate of energy dissipation compared to smooth chutes. Herein, detailed measurements were performed in a large-size 1V:0.8H stepped spillway model, with a steep slope typical of modern concrete gravity dams. Detailed two-phase flow measurements were conducted to characterise finely the self-aeration and air diffusion process downstream of the inception region of free-surface aeration. The bubble count rate profiles scaled with the instantaneous void fraction variance, yet the relationship was biased close to the invert under the influence of large-scale coherent structures. The rate of energy dissipation was calculated based upon the two-phase flow measurements and the results are compared with earlier result on similar steep invert slopes. At the downstream end of the stepped chute, the rate of energy dissipation ranged from 43% to 46%, more than twice that on a smooth-invert chute for a similar chute length and discharge range.