arXiv subjects

Yousheng Zhang

Publications and source records attributed to Yousheng Zhang.

5 recordsLinked to original sources

arXiv2026

Quantum algorithm for the nonlinear Schrödinger equation via the Lax-pair scattering

The nonlinear Schrödinger equation (NLSE) governs a broad class of wave phenomena, including deep-water waves, quantum turbulence, and solitons. The multiscale spatiotemporal coupling inherent in these systems imposes severe computational bottlenecks on classical high-fidelity numerical simulations. While quantum computing offers the potential for exponential speedup, its unitary dynamics pose a fundamental challenge to solve the NLSE. We propose a quantum framework based on the Lax-pair scattering for solving the 1D NLSE. Specifically, the physical field is first mapped into the spectral space via a quantum direct scattering circuit. Following a decoupled linear time evolution, the physical solution is reconstructed through an inverse scattering transform utilizing the quantum singular value transformation. Since the temporal evolution is performed analytically in the scattering domain, the framework bypasses iterative time stepping, rendering it highly advantageous for long-time simulations. To demonstrate the accuracy and noise resilience of this approach, we simulate a Gaussian wave packet under quantum noise, two-soliton collisions, breather dynamics, and modulational instability on a quantum emulator.

quant-ph↗

arXiv2025

A compressible Reynolds-averaged mixing model considering turbulent entropy and heat flux

In typical nature and engineering scenarios, such as supernova explosion and inertial confinement fusion, mixing flows induced by hydrodynamics interfacial instabilities are essentially compressible. Despite their significance, accurate predictive tools for these compressible flows remain scarce. For engineering applications, the Reynolds-averaged Navier-Stokes (RANS) simulation stands out as the most practical approach due to its outstanding computational efficiency. However, the majority of RANS mixing studies reported have concentrated on incompressible scenarios, with quite limited attention given to compressible cases. Moreover, most of the existing RANS mixing models demonstrate significantly inaccurate predictions for compressible mixing flow. This study develops a novel compressible RANS mixing model by incorporating physical compressibility corrections into the incompressible K-L-y mixing transition model recently proposed by Xie et al. (J. Fluid Mech., 1002, A31, 2025). Specifically, taking the density-stratified Rayleigh-Taylor mixing flows as representative compressible cases, we firstly analyze the limitations of the existing model for compressible flows, based on high-fidelity data and local instability criteria. Subsequently, the equation of state for a perfect gas and the thermodynamic Gibbs relation are employed to derive comprehensive compressibility corrections. The crucial turbulent entropy and heat flux are integrated into the closure of the key turbulent mass flux term of the turbulent kinetic energy equation. These corrections enable the model to accurately depict compressible mixing flows. Systematic validations confirm the efficacy of the proposed modeling scheme. This study offers a promising strategy for modeling compressible mixing flows, paving the way for more accurate predictions in complex scenarios.

physics.flu-dyn↗

arXiv2023

A local intermittency based Reynolds-averaged transition model for turbulent mixing induced by interfacial instabilities

Accurate prediction of mixing transition induced by interfacial instabilities is vital for engineering applications, but has remained a great challenge for decades. For engineering practices, Reynolds-averaged Navier-Stokes simulation (RANS) is the most viable method. However, existing RANS models for mixing problems are mostly designed for fully developed turbulence, failing to depict the locally spatio-temporal-dependent characteristic of transition. In the present study, the idea of the intermittent factor (denoted as $γ$), which has been widely used in boundary layer transition in aerospace engineering, is extended to the mixing problems. Specifically, a transport equation for $γ$ is built based on local flow variables, which is used to describe the locally spatio-temporal-dependent characteristic of transition. Furthermore, $γ$ is coupled into the widely used K-L turbulent mixing model to constrain the two key product sources terms that dominate the evolution of mixing, i.e. the Reynolds stress and the buoyancy effect. Subsequently, the simulations of two reshocked Richtmyer-Meshkov mixing cases with remarkable transition effects confirm that the proposed model has a good performance for predicting mixing transition. To the best of our knowledge, it is the first study that an extra transport equation for intermittent factor has been proposed for a RANS mixing transition model. More importantly, the present modeling framework is flexible and has the potential to be applied to other RANS models. It provides a promising strategy for more advanced modeling for mixing transition.

physics.flu-dyn↗

arXiv2023

Research on Named Entity Recognition in Improved transformer with R-Drop structure

To enhance the generalization ability of the model and improve the effectiveness of the transformer for named entity recognition tasks, the XLNet-Transformer-R model is proposed in this paper. The XLNet pre-trained model and the Transformer encoder with relative positional encodings are combined to enhance the model's ability to process long text and learn contextual information to improve robustness. To prevent overfitting, the R-Drop structure is used to improve the generalization capability and enhance the accuracy of the model in named entity recognition tasks. The model in this paper performs ablation experiments on the MSRA dataset and comparison experiments with other models on four datasets with excellent performance, demonstrating the strategic effectiveness of the XLNet-Transformer-R model.

cs.CL↗

arXiv2017

Consistent implementation of characteristic flux-split based finite difference method for compressible multi-material flows

In order to prevent velocity, pressure, and temperature spikes at material discontinuities occurring when the interface-capturing schemes inconsistently simulate compressible multi-material flows(when the specific heats ratio is variable),various non-conservative or quasi-conservative numerical models have been proposed. However, designing a consistent numerical algorithm, especially using the high-order characteristic flux-split based finite-difference method (CFS-FDM) is still an open question. In this study, a systematical analysis of previous algorithms of the consistent implementing the high-order CFS-FDM for such flows is performed, and the reasons of special treatments in these algorithms are revealed. Based on this analysis, a new general numerical methodology that successfully avoids any special treatments as those required in previously reported algorithms, is derived. In this new algorithm, we rewrite the non-conservative term as a conservative term with a source term containing velocity divergence. By consistently treating the advection velocity in the conservative term and velocity divergence in the source term by imposing a new additional criterion, specifically, that a multi-fluid algorithm should have the ability of maintaining a pure single-fluid, we finally derive a new general algorithm that does not need any special treatment, and is very convenient to implement. The results of some benchmark tests show that the final algorithm not only maintains the velocity, pressure, and temperature equlibria, but is also suitable for problems regarding the interaction of interfaces and strong shock and rarefaction waves.

physics.comp-ph↗