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Yancheng You

Bio: Yancheng You is an academic researcher from Xiamen University. The author has contributed to research in topics: Hypersonic speed & Lattice Boltzmann methods. The author has an hindex of 14, co-authored 92 publications receiving 587 citations. Previous affiliations of Yancheng You include German Aerospace Center & Nanjing University of Aeronautics and Astronautics.


Papers
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Journal ArticleDOI
TL;DR: The topics covered include the operating principles and characteristics of three typical FCs, issues faced by FC-powered UAVs, specific roles of other electric power sources, pure electric hybrid constructions of FC hybrid propulsion systems, hybrid engine-electric FC hybrid propelled systems, potential impacts of various flight factors, energy management strategies, and similarities/differences of FC hybrids in other vehicle applications.

74 citations

Journal ArticleDOI
TL;DR: Results demonstrate that proposed CMWOA outperforms other three methods in most cases regarding several performance indicators, and is successfully applied to three real world problems, which further verifies the practicality of proposed algorithm.

67 citations

Journal ArticleDOI
TL;DR: In this article, an experiment was performed to study the deflagration to detonation transition (DDT) process in a detonation chamber with a reactive transverse methane-oxygen mixture jet in cross-flow (JICF) and showed that the JICF can distinctly accelerate flame propagation and shorten the DDT time and distance.

55 citations

Journal ArticleDOI
TL;DR: This paper provides and proves a sufficient and necessary condition of achieving the directed graphical affine localizability, and it only needs that the leaders have a generic configuration and the followers are accessible to the subset of leaders.

38 citations

Journal ArticleDOI
01 Jan 2013
TL;DR: In this article, the low momentum flux ratio jet in the HyShot II scramjet combustor is studied by DES (Detached Eddy Simulation) and RANS (Reynolds-Averaged Navier-Stokes) methods.
Abstract: The low momentum flux ratio jet in the HyShot II scramjet combustor is studied by DES (Detached Eddy Simulation) and RANS (Reynolds-Averaged Navier–Stokes) methods The flow structure near the injector, shock pattern in the symmetry plane as well as the instantaneous coherent structures are presented and explained Further insight into the flow physics is obtained by visualizing instantaneous coherent structures The formation of Ω-shaped vortices, which was previously observed in experiments but never well-studied numerically, is discussed in detail A new schematic of flow physics is proposed to enhance the understanding of the low momentum flux ratio jet Compared to the DES result, the RANS method is unable to capture the dynamics of turbulent structures The DES method provides much detailed information about mixing patterns and a more reliable mixing efficiency than the RANS result The RANS method over-predicts the eddy-viscosity during turbulence modeling and suppresses unsteady turbulent fluctuations by time averaging, which results in a 25% over-estimation of the mixing efficiency

35 citations


Cited by
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01 Apr 1992
TL;DR: In this paper, the authors proposed a monotone integrated large eddy simulation approach, which incorporates a form of turbulence modeling applicable when the large-scale flows of interest are intrinsically time dependent, thus throwing common statistical models into question.
Abstract: Fluid dynamic turbulence is one of the most challenging computational physics problems because of the extremely wide range of time and space scales involved, the strong nonlinearity of the governing equations, and the many practical and important applications. While most linear fluid instabilities are well understood, the nonlinear interactions among them makes even the relatively simple limit of homogeneous isotropic turbulence difficult to treat physically, mathematically, and computationally. Turbulence is modeled computationally by a two-stage bootstrap process. The first stage, direct numerical simulation, attempts to resolve the relevant physical time and space scales but its application is limited to diffusive flows with a relatively small Reynolds number (Re). Using direct numerical simulation to provide a database, in turn, allows calibration of phenomenological turbulence models for engineering applications. Large eddy simulation incorporates a form of turbulence modeling applicable when the large-scale flows of interest are intrinsically time dependent, thus throwing common statistical models into question. A promising approach to large eddy simulation involves the use of high-resolution monotone computational fluid dynamics algorithms such as flux-corrected transport or the piecewise parabolic method which have intrinsic subgrid turbulence models coupled naturally to the resolved scales in the computed flow. The physical considerations underlying and evidence supporting this monotone integrated large eddy simulation approach are discussed.

849 citations

Journal ArticleDOI
TL;DR: An overview of the state-of-the-art attention models proposed in recent years is given and a unified model that is suitable for most attention structures is defined.

620 citations

Journal ArticleDOI
TL;DR: In this article, the transverse jet in supersonic crossflows has been summarized systematically from four aspects, namely single injection, multiport injection, interaction between jet and vortex generator, and interaction between the jet and shock wave.

216 citations

01 Dec 2010
TL;DR: In this article, a modified calibration of MELTS optimized for silicic systems, dubbed rhyolite-MELTS, using early erupted Bishop pumice as a reference.
Abstract: Silicic magma systems are of great scientific interest and societal importance owing to their role in the evolution of the crust and the hazards posed by volcanic eruptions. MELTS is a powerful and widely used tool to study the evolution of magmatic systems over a wide spectrum of compositions and conditions. However, the current calibration of MELTS fails to correctly predict the position of the quartz þ feldspar saturation surface in temperature, pressure and composition space, making it unsuitable to study silicic systems. We create a modified calibration of MELTS optimized for silicic systems, dubbed rhyolite-MELTS, using early erupted Bishop pumice as a reference. Small adjustments to the calorimetrically determined enthalpy of formation of quartz and of the potassium end-member of alkali feldspar in the MELTS calibration lead to much improved predictions of the quartz þ feldspar saturation surface as a function of pressure. Application of rhyolite-MELTS to the Highland Range Volcanic Sequence (Nevada), the Peach Spring Tuff (Arizona^Nevada^California), and the late-erupted Bishop Tuff (California), using compositions that vary from trachydacite to high-silica rhyolite, shows that the calibration is appropriate for a variety of fluid-bearing silicic systems. Some key observations include the following. (1) The simulated evolutionary paths are consistent with petrographic observations and glass compositions; further work is needed to compare predicted and observed mineral compositions. (2) The nearly invariant nature of silicic magmas is well captured by rhyolite-MELTS; unusual behavior is observed after extensive pseudo-invariant crystallization, suggesting that the new calibration works best for relatively small (i.e.550 wt %) crystallization intervals, comparable with what is observed in volcanic rocks. (3) Our success with rhyolite-MELTS shows that water-bearing systems in which hydrous phases do not play a critical role can be appropriately handled; simulations are sensitive to initial water concentration, and although only a pure-H2O fluid is modeled, suitable amounts of water can be added or subtracted to mimic the effect of CO2 in fluid solubility. Our continuing work on natural systems shows that rhyolite-MELTS is very useful in constraining crystallization conditions, and is particularly well suited to explore the eruptive potential of silicic magmas. We show that constraints placed by rhyoliteMELTS simulations using late-erupted Bishop Tuff whole-rock and melt inclusion compositions are inconsistent with a vertically stratified magma body.

186 citations