Optimal design of structures with respect to vibration attenuation property is essential and basically required in many structural engineering concepts. A new type of metastructure composed of periodic lattices and embedded resonators is proposed for vibration suppression. The lightweight periodic lattice structure, which combines body-centered cubic and face-centered cubic structural configurations, is fabricated by selective laser melting with AlSi10Mg. Furthermore, the lattice structures periodically filled with the tin–bismuth alloy, which has a high density and a low melting point, can be used as local resonators to open bandgap in a metastructure. Experiments and numerical simulations are conducted to investigate the bandgap characteristics and vibration damping behavior of the proposed metastructure. The results of the simulation and the experiment data agree satisfactorily. It is demonstrated that the proposed structure can generate a complete bandgap in the low-frequency range, which is useful for machining vibration suppression. To optimize the structure, the influence of structural parameters on the vibration dispersion effect is further studied. The bandgap position and bandwidth can be flexibly adjusted by varying structure parameters, i.e., the radii of the external frames, the spatial scale factor of the metastructure, and the filling fraction of the resonator. This study provides a new possibility for metastructure with a low-frequency bandgap by filling the lattice structures with tin–bismuth alloy.
Figures are missing from the paper. Abstract Much attention is now paid to the development of low permeable reservoirs. However, there is almost a dearth of literature on the study of relative permeabilities in rock samples with low permeability. Group J2S of QL Reservoir is characteristics of low porosity, low permeability and low crude oil viscosity. Oil-water relative permeabilities of QL Reservoir have been measured at two different oil/water viscosity ratios by using unsteady-state method. The experimental results showed that the oil-water relative permeabilities change with the changing of oil/water viscosity' ratio. It is explained that the oil-water relative permeabilities measured at oil/water viscosity ratio close to the oil/water viscosity ratio under reservoir condition coincide with the practical situation of QL Reservoir by comparing the injection-production ratio calculated from laboratory water flooding data with the practical one. The irreducible water saturations in QL Reservoir rocks range from 27.7% to 35.8% and its average value is 31.5%. The water flooding residual oil saturations range from 11.6% to 21.7% and its average value is 14.8%. Most of the water relative permeabilities at residual oil saturations range from 0.23to 0.50 and its average value is about 0.388. Oil-water 2-phase flowing limit ranges from 47.8% to 59.0% and its average value is about 53.7%. Moreover, the end water relative permeabilities are correlated with the air permeabilities of rock samples. That is, the bigger the air permeabilities of the rock samples, the higher the end water relative permeabilities. Introduction The development of a reservoir by water injection usually includes an oil-water 2-phase or an oil-gas-water 3-phase flowing in porous media(reservoir rock). The efficiency of development by water injection is closely related to the multi-phase flow in porous media which is dependent on rock permeability, pore structure, wettability, capillary pressure, interfacial tension, viscosity of fluid and relative permeability of each phase. The basic idea of relative permeability is simple. However, the factors to affect relative permeability are very complex. Many literatures about relative permeability published now explain that it is very difficult to obtain really representative and true relative permeability data. P. 497
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.