A Note on Leakage Jet Forces: Application in the Modelling of Digital Twins of Hydraulic Valves

The proper modelling of fluid flow through annular gaps is of great interest in leakage calculations for many applications in fluid power technology. However, while detailed numerical simulations are certainly possible, they are very time consuming, in various cases prone to numerical instabilities and may not even include all physically relevant effects. This is an issue especially in system simulations, where a large set of computations is needed in order to prepare the lookup-tables for the required input fields. In this work, an analytical approximation for the shear force, which is induced by viscous flow between two eccentric cylinders, is presented. This relation, and its derivation, mimics and enhances the well-known Piercy-relation for the corresponding volume flow that is utilized in state-of-the-art system simulation tools. To determine its range of validity, the analytical relation for the shear force is compared to 3D-simulations. Additionally, an application of this approximation for creating digital twins of hydraulic valves is also discussed in this work.

Effect of Finned-Tube on the Enhancement of Melting Process of PCM in Eccentric Cylinders

The process of melting of a phase-change material (PCM) in eccentric horizontal cylinders geometry is studied numerically. Numerical simulations are performed for symmetric melting of phase change material between the two cylinders using the finite volume method. The inner cylinder is a finned-tube to enhance the heat transfer between the inner cylinder and the PCM. Inner cylindrical is considered as hot wall while outer is insulated. These simulations show the melting process from the beginning to the end. As result, it is found that the use of fins on the inner tube increases the melting process by decreasing the time of melting by 72.72 %.

Electro-thermo-convection in dielectric liquid subjected to partial unipolar injection between two eccentric cylinders

Purpose The purpose of this work is to highlight the effects of partial unipolar injection on electro-thermo-convection (ETC) in dielectric liquid contained between two eccentric cylinders. Design/methodology/approach A finite volume method was used to solve governing equations. The study is performed for different parameters, such as radius ratio (0.2 ≤ Γ ≤ 0.6), dimensionless electric Rayleigh number (0 ≤ T ≤ 900), eccentricity (−0.4 ≤ e ≤ 0.4) and thermal Rayleigh number (10 ≤ Ra ≤ 5.105). Findings It is found that heat transfer increases with increase in dimensionless electric Rayleigh number and eccentricity ratio. Originality/value The originality of this work is to analyze the ETC in dielectric liquid subjected to partial unipolar injection between two eccentric cylinders

A comparative study of Cu nanoparticles under slip effects through oblique eccentric tubes, a biomedical solicitation examination

The particular mechanical, chemical, and thermodynamic properties of nanofluids build up a subject of immense interest for researchers of all areas. Such types of fluids have special significance in biomedical research due to their novel and immeasurable applications the in latest biomedical solicitation examination, such as drug delivery. Therefore, the focus of this study is to investigate the comparative study of copper nanoparticles under slip effects through oblique eccentric cylinders. For peristaltic pumping, an appropriate model is presented and its application is urged because of the way that the thread infusion inside the human body empowers creation of a methodology for restorative inserting with the slightest possible surgical injury. The outer lying tube has a wave of sinosiodual nature whereas the inner thread is of velocity V. Lubrication approach is used to calculate the dimensionless expressions for temperature and velocity profile. The inner tube satisfied no-slip condition while the outer tube has partial slip condition. The innovation with different sundry parameters is also presented via graphs. The attributes of this study are presented in the last section and a good agreement is found with existing literature. Significant increase in the heat transfer rate is observed in the presence of thermal slip parameter with the inclusion of copper nanoparticles. It is also found that the pressure rise enhances in the retrograde pumping region with the increase in inclination angle. It is important to note that slip causes decreases in the trapped bolus. This analysis finds valuable theoretical information for nanoparticle use as a drug agent in the field of bio-inspired applications.