Results 21 to 30 of about 1,497 (181)

Pressure fluctuation prediction in pump mode using large eddy simulation and unsteady Reynolds-averaged Navier–Stokes in a pump–turbine

open access: yesAdvances in Mechanical Engineering, 2016
For pump–turbines, most of the instabilities couple with high-level pressure fluctuations, which are harmful to pump–turbines, even the whole units. In order to understand the causes of pressure fluctuations and reduce their amplitudes, proper numerical ...
De-You Li   +5 more
doaj   +1 more source

Transient Flow-Induced Stress Investigation on a Prototype Reversible Pump–Turbine Runner

open access: yesEnergies
Pump–turbine units with high heads are subjected to strong pressure pulsations from the unsteady transient flow in fluid channels, which can produce severe vibrations and high stresses on the pump–turbine structural components.
Dehao Zhang   +5 more
doaj   +1 more source

Operation strategy of the heliostat field and receiver based on categorization of DNI fluctuation types

open access: yesScientific Reports
Transient changes in receiver heat are due to Direct Normal Irradiance (DNI) fluctuations, requiring operational strategies for receiver safety in cloudy weather.
Jing Nie   +3 more
doaj   +1 more source

Influence of Weak Compressibility on the Hydrodynamic Performance Evaluation of Pump Turbines in the Pump Mode

open access: yesScience and Technology of Nuclear Installations, 2022
In general, weak compressibility is one of the properties of liquids. That is, in actual operation of hydraulic machinery, the flow is weakly compressible.
Fangfang Zhang   +5 more
doaj   +1 more source

Transducers Across Scales and Frequencies: A System‐Level Framework for Multiphysics Integration and Co‐Design

open access: yesAdvanced Materials Technologies, EarlyView.
Transducers convert physical signals into electrical and optical representations, yet each mechanism is bounded by intrinsic trade‐offs across bandwidth, sensitivity, speed, and energy. This review maps transduction mechanisms across physical scale and frequency, showing how heterogeneous integration and multiphysics co‐design transform isolated ...
Aolei Xu   +8 more
wiley   +1 more source

Waveguide Photoactuators: Materials, Fabrication, and Applications

open access: yesAdvanced Robotics Research, EarlyView.
Waveguide photoactuators convert guided light into mechanical motion. Their tethered‐flexible design enables minimally invasive surgery and confined‐space robotics. This review aims to guide materials selection, device design, and system integration, accelerating the transition of waveguide photoactuators from laboratory prototypes to versatile ...
Minjie Xi   +4 more
wiley   +1 more source

Causal‐Guided Ultra‐Long‐Term Time Series Forecasting Via Anticipated Covariates

open access: yesAdvanced Science, EarlyView.
Often treated as unknown, information from the future remains underutilized.We demonstrate that in a coupled dynamical system, providing the future state of the effect enables accurate forecasting of the cause for a long timesteps. A time series forecasting paradigm that introduces anticipated covariates to represent such known future states is ...
Jintong Zhao   +4 more
wiley   +1 more source

Systematic analysis on the energy loss in pump-turbines

open access: yesAdvances in Mechanical Engineering
The pump-turbine is a key component in pumped-storage power stations, operating under complex conditions. RANS (Reynolds-Averaged Navier-Stokes) is commonly used for numerical simulations, but the differences among various RANS models under different ...
Miao Guo   +5 more
doaj   +1 more source

Geometrical Optimization of Pump-As-Turbine (PAT) Impellers for Enhancing Energy Efficiency with 1-D Theory

open access: yesEnergies, 2020
This paper presents a multi-objective optimization strategy for pump-as-turbines (PAT), which relies on one-dimensional theory and analysis of geometrical parameters.
Longyan Wang   +3 more
doaj   +1 more source

Embedding Chemistry and Pharmacy Into Sustainability

open access: yesAngewandte Chemie International Edition, EarlyView.
Chemistry and pharmacy provide products and processes that are indispensable for our high living standard. To understand their relationship with sustainability is important to allow them to contribute to sustainability in a sustainable manner. An integrated overview of green, circular, and sustainable chemistry and pharmacy is given and how they have t
Klaus Kümmerer
wiley   +1 more source

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