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工业非介入式负荷监测研究综述

中国测试 2025年第1期51卷 11-23页

作者：黄颖祺颜钟宗郝芃斐温和湖南大学电气与信息工程学院湖南长沙410082

非介入式负荷监测(NILM)能实时获取工业设备负荷状态和能耗信息,为工业节能提供重要数据支撑。NILM在居民负荷监测中得到较好的应用,但在工业应用中遇到挑战,主要原因是:1)工业数据涉及行业隐私,公开的工业NILM数据集稀缺;2)工业设备运... 详细信息

非介入式负荷监测(NILM)能实时获取工业设备负荷状态和能耗信息,为工业节能提供重要数据支撑。NILM在居民负荷监测中得到较好的应用,但在工业应用中遇到挑战,主要原因是:1)工业数据涉及行业隐私,公开的工业NILM数据集稀缺;2)工业设备运行特性和工作模式复杂多变。该文从工业NILM数据集、工业负荷特征的提取和选择方法、工业负荷辨识与电量分解方法等方面综述了工业NILM技术的发展现状。在此基础上,对工业NILM模型的优化、适应多行业负荷辨识模型迁移、大规模负荷辨识模型轻量化、负荷辨识评价标准等方面进行展望。该文的工作对推动工业非介入式负荷监测的研究和应用有一定的参考意义。

关键词：工业非介入式负荷监测负荷分解综述

The measurement error analysis when a pitot probe is used in supersonic air flow

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Science China(Physics,Mechanics & Astronomy) 2011年第4期54卷 690-696页

作者： ZHANG XiWen hao pengfei YAO ZhaoHui School of Aerospace Tsinghua University Beijing 100084 China

Pitot probes enable a simple and convenient way of measuring mean velocity in air flow. The contrastive numerical simulation between free supersonic airflow and pitot tube at different positions in supersonic air flow was performed using Navier-Stokes equations, the ENN scheme with time-dependent boundary conditions （TDBC） and the Spalart-Allmaras turbulence model. The physical experimental results including pitot pressure and shadowgraph are also presented. Numerical results coincide with the experimental data. The flow characteristics of the pitot probe on the supersonic flow structure show that the measure- ment gives actually the total pressure behind the detached shock wave by using the pitot probe to measure the total pressure. The measurement result of the distribution of the total pressure can still represent the real free jet flow. The similar features of the intersection and reflection of shock waves can be identified. The difference between the measurement results and the actual ones is smaller than 10%. When the pitot probe is used to measure the region of L=0-4D, the measurement is smaller than the real one due to the increase of the shock wave strength. The difference becomes larger where the waves intersect. If the pitot probe is put at L=SD-10D, where the flow changes from supersonic to subsonic, the addition of the pitot probe turns the original supersonic flow region subsonic and causes bigger measurement errors.

关键词： pitot probe supersonic air flow numerical simulation measurement error

Evaporating behaviors of water droplet on superhydrophobic surface

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Science China(Physics,Mechanics & Astronomy) 2012年第12期55卷 2463-2468页

作者： hao pengfei LV CunJing HE Feng Department of Engineering Mechanics Tsinghua University Beijing 100084China

We investigated the dynamic evaporating behaviors of water droplet on superhydrophobic surfaces with *** experimental data showed that receding contact angles of the water droplet increased with the decreasing of the scale of the micropillars during evaporation,even though the solid area fractions of the microstructured substrates remained *** also experimentally found that the critical contact diameters of the transition between the Cassie-Baxter and Wenzel states are affected not only by the geometrical parameters of the microstructures,but also by the initial volume of the water *** measured critical pressure is consistent with the theoretical model,which validated the pressure-induced impalement mechanism for the wetting state transition.

关键词： droplet evaporation superhydrophobic

Study of dynamic hydrophobicity of micro-structured hydrophobic surfaces and lotus leaves

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Science China(Physics,Mechanics & Astronomy) 2011年第4期54卷 675-682页

作者： hao pengfei YAO ZhaoHui ZHANG XiWen Department of Engineering Mechanics Tsinghua University Beijing 100084 China

The dynamic wetting characteristics of water droplets on silicon wafers with microscale regular pillars structures and fresh lotus leaves are investigated *** measured the static contact angle,contact angle hysteresis,and roll-off angle of water droplets on both of these superhydrophobic surfaces with a high speed contact angle *** dynamic contact angles and internal velocity distribution of water droplets on superhydrophobic surfaces were studied with a high-speed camera system and a particle image velocimetry (PIV) system,*** found that the acceleration of water droplets when they slide off lotus leaves is greater than that of water droplets sliding off the silicon wafers with microscale pillar structures although the static contact angles of water droplets on lotus leaves are slightly smaller than those on the silicon *** reason is that water droplets sliding off lotus leaves have smaller contact angle hysteresis and larger slip *** results indicate that the dynamic contact angle hysteresis and sliding acceleration of liquid droplets are more suitable for reflecting the hydrophobicity of material surfaces compared with static contact *** experiments also show that lotus leaves with multiscale micro/nanostructures have stronger hydrophobicity and self-cleaning properties compared with the micro-structured superhydrophobic surfaces.

关键词： droplet hydrophobicity contact angle PIV

Mechanical behavior of pathological and normal red blood cells in microvascular flow based on modified level-set method

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Science China(Physics,Mechanics & Astronomy) 2016年第1期59卷 66-74页

作者： XiWen Zhang FangChao Ma pengfei hao ZhaoHui Yao Department Engineering Mechanics School of Aerospace Tsinghua University

The research of the motion and deformation of the RBCs is important to reveal the mechanism of blood diseases. A numerical method has been developed with level set formulation for elastic membrane immersed in incompressible fluid. The numerical model satisfies mass and energy conservation without the leaking problems in classical Immersed Boundary Method(IBM), at the same time, computing grid we used can be much smaller than the general literatures. The motion and deformation of a red blood cell(including pathological & normal status) in microvascular flow are simulated. It is found that the Reynolds number and membrane's stiffness play an important role in the transmutation and oscillation of the elastic membrane. The normal biconcave shape of the RBC is propitious to create high deformation than other pathological shapes. With reduced viscosity of the interior fluid both the velocity of the blood and the deformability of the cell reduced. With increased viscosity of the plasma both the velocity of the blood and the deformability of the cell reduced. The tank treading of the RBC membrane is observed at low enough viscosity contrast in shear flow. The tank tread fixed inclination angle of the cell depends on the shear ratio and viscosity contrast, which can be compared with the experimental observation well.

关键词： red blood cell microvascular flow shear flow fluid-structure interaction level set

Effects of gas compressibility and surface roughness on the flow in microfluidic devices

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Science China(Physics,Mechanics & Astronomy) 2011年第4期54卷 711-715页

作者： YAO ZhaoHui hao pengfei ZHANG XiWen School of Aerospace Tsinghua University Beijing 100084 China

With the development of the micro-electro-mechanical system (MEMS),the flow characteristics in micro-channels have drawn increasing *** this paper,numerical simulations are conducted to investigate the flow characteristics of compressible flow through micro-channels and *** improved surface roughness viscosity model is used to simulate the effect of surface roughness on micro-channels flow *** this model,better agreements between the computational results and the experimental data are *** result indicates that the surface roughness is one of the important factors affecting the flow characteristics of gas through *** numerical investigation on the expansion channel shows that by using the laminar model that considers surface roughness,the computational results and experimental data are consistent when Re*** on the synthetic model with considerations of turbulence viscosity and surface roughness,the numerical results and the experimental data are identical.

关键词： microfluidic devices surface roughness compressible characteristics early transition

Water droplet impact on superhydrophobic surfaces with microstructures and hierarchical roughness

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Science China(Physics,Mechanics & Astronomy) 2014年第7期57卷 1376-1381页

作者： hao pengfei LV CunJing NIU FengLei YU Yu Department of Engineering Mechanics Tsinghua University State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University

Quantitative correlation between the critical impact velocity of droplet and geometry of superhydrophobic surfaces with microstructures is systematically *** data shows that the critical impact velocity induced wetting transition of droplet on the superhydrophobic surfaces is strongly determined by the perimeter of single micropillar,the space between the repeat pillars and the advancing contact angle of the sidewall of the *** proposed model agrees well with the experimental results,and clarifies that the underlying mechanism which is responsible for the superhydrophobic surface with hierarchical roughness could sustain a higher liquid pressure than the surfaces with microstructures.

关键词： impact velocity superhydrophobic advancing contact angle

Wetting property of smooth and textured hydrophobic surfaces under condensation condition

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Science China(Physics,Mechanics & Astronomy) 2014年第11期57卷 2127-2132页

作者： hao pengfei LV CunJing YAO ZhaoHui NIU FengLei Department of Engineering Mechanics Tsinghua University State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University

Static and dynamic wetting behaviors of sessile droplet on smooth,microstructured and micro/nanostructured surface under condensation condition are systematically *** contrast to the conventional droplet wetting on such natural materials by dropping,we demonstrate here that when dropwise condensation occurs,the sessile droplet will transit from the Cassie-Baxter wetting state to the Wenzel wetting state or partial Cassie-Baxter wetting state on the microstructured surface or the micro/nanostructured surface,which leads to a strong adhesion between the droplet and the *** contrast,the apparent contact angle and the sliding angle on the smooth surface changes a little before and after the condensation because of small *** analysis shows that the roughness factor controls the adhesion force of the droplet during condensation,and a theoretical model is constructed which will be helpful for us to understand the relationship between the adhesion force and the geometry of the surface.

关键词： condensation hydrophobic roughness droplet systematically wetting apparent nanotube structured diameters

Drag reduction in ultrahydrophobic channels with micro-nano structured surfaces

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Science China(Physics,Mechanics & Astronomy) 2010年第7期53卷 1298-1305页

作者： LU Si YAO ZhaoHui hao pengfei FU ChengSong School of Aerospace Tsinghua UniversityBeijing 100084China

A series of experiments have been performed to demonstrate the significant drag reduction of the laminar flow in the ultrahydrophobic channels with dual-scale micro-nano structured ***,in previous experiments,the ultrahydrophobic surfaces were fabricated with micro-structures or nano-structures and the channels were on the *** the drag reduction in macro-scale channels few reports are *** a new method was developed to fabricate ultrahydrophobic surfaces with micro-nano hierarchical structures made from carbon *** drag reductions up to 36.3% were observed in the macro-channels with ultrahydrophobic *** micro-PIV was used to measure the flow velocity in *** with the traditional no-slip theory at walls,a significant slip velocity was observed on the ultrahydrophobic surfaces.

关键词： ultrahydrophobic surfaces hierarchical structure laminar flow drag reduction velocity slip