Developing flexible Li-CO2 batteries is a promising approach to reuse CO2 and simultaneously supply energy to wearable electronics. However, all reported Li-CO2 batteries use liquid electrolyte and lack robust electrolyte/electrodes structure, not providing the safety and flexibility required. Herein we demonstrate flexible liquid-free Li-CO2 batteries based on poly(methacrylate)/poly(ethylene glycol)-LiClO4-3 wt %SiO2 composite polymer electrolyte (CPE) and multiwall carbon nanotubes (CNTs) cathodes. The CPE (7.14×10−2 mS cm−1) incorporates with porous CNTs cathodes, displaying stable structure and small interface resistance. The batteries run for 100 cycles with controlled capacity of 1000 mAh g−1. Moreover, pouch-type flexible batteries exhibit large reversible capacity of 993.3 mAh, high energy density of 521 Wh kg−1, and long operation time of 220 h at different degrees of bending (0–360°) at 55 °C.

Flexible Li-CO2 Batteries with Liquid-Free Electrolyte

Experimental research on water-lubricated marine stern tube bearings in conditions of improper lubrication and cooling causing rapid bush wear

In this study, a fully three-dimensional CFD analysis and multi-phase flow phenomena, has been successfully implemented for simulation of hydrodynamic journal bearing considering the realistic deformations of the bearing with Fluid Structure Interactions (FSI) along with cavitation. Mixture model is used to model cavitation in the bearing and parametric modelling is used for modifying the flow domain due to deformation. Both systems are coupled and design optimization based on multi objective genetic algorithm (MOGA), is used to obtain optimized solution of the attitude angle and eccentricity for the combination of operating speed and load. In the study of bearings with and without effects of cavitation, it is observed that maximum pressure values drop when cavitation is considered in the bearing. Also there is decrease in maximum pressure when elastic deformation in the bearing is considered. The oil vapour distribution goes on increasing with the increase in shaft speed, thus lowering the magnitude of the pressure build up in the bearing. Multiphase study of bearings with cavitation hence becomes extremely important in case of bearings operating with higher speeds. The experimental data obtained showed very good agreements with numerical results and considerable reduction in computation time is observed.

Multiphase flow analysis of hydrodynamic journal bearing using CFD coupled Fluid Structure Interaction considering cavitation

Experimental research on water lubricated three layer sliding bearing with lubrication grooves in the upper part of the bush and its comparison with a rubber bearing

Tribology review of blended bulk polymers and their coatings for high-load bearing applications

Fluid film thickness in a compliant foil bearing is greatly influenced by the deflection of the bearing structure. Therefore, in order to properly model performance of a foil bearing, it is mandatory that the deflection of the compliant bearing structure due to the generated hydrodynamic pressure is determined accurately. This article proposes an easy-to-use two-dimensional model, which takes into account detailed geometry of the bump foil-top foil assembly and the interaction between bumps and which can predict the bearing deflection and stresses due to an arbitrary pressure load. The proposed model is first validated using a finite element analysis and the results available in the literature and then used to conduct a parametric study investigating the influence of bump foil geometry, the coefficient of friction between the bearing components, and the type of loading on the structural properties of the bearing. The most important parameters are also identified. The proposed analytical model is completel...

Structural Properties of Foil Bearings: A Closed-Form Solution Validated with Finite Element Analysis

Water-lubricated stern tube bearing - experimental and theoretical investigations of thermal effects

Part of the heat generated by the shearing of the lubricating film during operation of a
hydrodynamic bearing is transferred to the bearing components. In the case of the pad,
which is usually fully submerged in the lubricating oil, heat is further transferred at the
pad free walls to the oil by convection. This mechanism causes a thermal gradient in a
pad and, consequently, its thermal deflection. In large hydrodynamic thrust bearings,
thermal deflection of the pads is an important phenomenon influencing bearing performance.
For such bearings, pad distortion can reach the level of hydrodynamic film thickness
and can significantly change the bearing’s properties. In this paper, the study of the
influence of the heat convection coefficient on the predicted performance of a large
hydrodynamic thrust bearing is presented. Two sets of convection coefficients at the pad
free surfaces are investigated with the use of thermo-elasto-hydrodynamic (TEHD) calculations.
An analysis is carried out for the Itaipu hydro turbine thrust bearing with the
outer diameter equal to 5.2 m, which is one of the biggest hydro power plants in the
world. The results of the theoretical predictions are compared to the measured data collected
during bearing operation.

Study of the Influence of Heat Convection Coefficient on Predicted Performance of a Large Tilting-Pad Thrust Bearing

Hydrodynamic thrust bearings, used to carry axial loads in heavily loaded shafts of water power plants hydro turbines, can reach outer diameters even exceeding 5 m. In such large objects scale effe...

Large hydrodynamic thrust bearing: Comparison of the calculations and measurements

Fluid–structure interaction technique seems to be one of the most promising possibilities for theoretical analysis of lubrication problems. It allows coupling of different physical fields in one co...

Michał Wodtke

Papers

Structural Properties of Foil Bearings: A Closed-Form Solution Validated with Finite Element Analysis

Water-lubricated stern tube bearing - experimental and theoretical investigations of thermal effects

Study of the Influence of Heat Convection Coefficient on Predicted Performance of a Large Tilting-Pad Thrust Bearing

Large hydrodynamic thrust bearing: Comparison of the calculations and measurements

Application of the fluid–structure interaction technique for the analysis of hydrodynamic lubrication problems