Mechanical

Calibration of a small size hexapod machine tool using coordinate measuring machine
Hexapod machine tool (HMT) is a device designed for micro milling; however, the deviations of the HMT’s kinematic parameters due to manufacture and assembly errors can definitely affect its running accuracy. To identify the real kinematic parameters so as to improve the running accuracy of the HMT, a novel calibration test was performed on a bridge-type coordinate measuring machine. In th...


Flow behavior of non-spherical particle flowing in hopper
Ellipsoidal particles flowing in the hopper were simulated by using the discrete element method (DEM), and described by the multi-element method. The contact detection algorithm and equations for ellipsoidal particle motion in hopper were developed. And the simulation results were confirmed by experiment. Additionally, the mass flow rate, pressure distribution and velocity distribution of two k...
Dynamic analysis of embedded PVDF nanoplate subjected to a moving nanoparticle on an arbitrary elliptical path
In the present study, dynamic qualitative analysis and vibration response of an embedded poly-vinylidene fluoride (PVDF) nanoplate under a moving nanoparticle on an arbitrary elliptical path are investigated. The Coulomb friction model is applied to calculate the work done by the moving nanoparticle. The surrounding elastic medium is simulated by Pasternak foundation. The PVDF nanoplate is subj...


An effective wetting and drying algorithm for numerical shallow water flow models
This paper presents a simple and effective method to model the wetting and drying of coastal areas by the tide. The approach considers an equivalent "rough-porous layer" (RPL), wetting and drying method. The method can be easily implemented in finite elements, which makes it useful in numerical modeling of natural water bodies with intricate topographies. Some benchmark tests are devi...
Research on the design and control strategy for a flow-coupling-based hydraulic hybrid excavator
This paper presents a hybridization structure for the flow coupling of a hydraulic hybrid excavator. Multiple energy regeneration systems are used as the energy source for the hydraulic hybrid excavator. The flow-coupling structure is designed on the basis of practical working conditions and then integrated into a 23 ton excavator as the experimental platform to facilitate power system design a...


Validation of a basic combined-slip tyre model for use in friction estimation applications
Tyre modelling is an important part of understanding and estimating the tyre–road friction. In this paper a basic steady-state tyre model for the combined-slip case is derived. The model is intended to be used in friction estimations applications, where the model complexity is of high priority. The model, described using only two parameters, is validated with measured data from various co...
Gear shift schedule design for multi-speed pure electric vehicles
As pure electric vehicles are considered to be a major growth trend in the automotive industry, research into and development of efficient electric powertrain systems and related control technologies have become popular research topics. The growing importance and use of multi-speed transmissions in these vehicles make shift schedule design and research a crucial aspect of the powertrain systems...

Simulations of the diesel engine performance with a two-stage sequential turbocharging system at different altitudes
The turbocharging system of a six-cylinder diesel engine is analysed. It shows that the original single-stage turbocharger cannot meet the requirement that the engine should maintain a certain power output at different altitudes owing to the significant differences in the air density. A two-stage sequential turbocharging system is proposed, and the specific parameters of this turbocharging syst...
A study on the spray and engine combustion characteristics of diesel-dimethyl ether fuel blends
The purpose of this study was to compare the spray characteristics, the combustion characteristics and the emissions (nitrogen oxides, carbon monoxide, hydrocarbon and smoke) of typical fuels (100% diesel and 100% dimethyl ether) and diesel–dimethyl ether fuel blends in a constant-volume chamber and a single-cylinder direct-injection diesel engine. The spray characteristics were investiga...

Characterising heavy-duty fuel systems: a critique of industry practice and challenges
Fuel system components must perform optimally to ensure the maximum fuel economy and the minimum emissions. The key to optimised performance is effective characterisation of the system in the factory. This paper describes methods for discerning the features of a fuel injection system’s performance during built-unit testing. First, a background is given, highlighting the impact of environm...
Thermomechanical coupling effect of graphite electrodes upon the electric arc furnace dynamics
Prediction of the dynamic behavior of electrodes of the electric arc furnace (EAF) fed by AC current is rather difficult because of several phenomena superposed, particularly during the first step of the melting process, i.e. the so-called perforation, and in case of the melting of scrap. Unexpected ruptures of electrodes are often observed as a consequence of vibration. Dynamic excitation is a...

Cold Nuclear Fusion explained by hydrogen embrittlement and piezonuclear fissions in the metallic electrodes—Part I: Ni–Fe and Co–Cr electrodes
Several evidences of anomalous nuclear reactions occurring in condensed matter have been observed in the phenomena of electrolysis, fracture (solids), and cavitation (liquids). Despite the great amount of experimental results coming from the so-called Cold Nuclear Fusion and low energy nuclear reactions research activities, the comprehension of these phenomena still remains unsatisfactory. On t...
Scheduling FMS problems with heuristic search function and transition-timed Petri nets
In flexible manufacturing system (FMS) scheduling problems, the production process and constraints can be modeled by Petri nets concisely. However, the search space for an optimal or suboptimal schedule will exponentially grow with the increase of problem size. In this paper, we consider the scheduling problems of FMS in the framework of timed-transition Petri nets. In the framework, each token...
Multi-layered mesh generation and user subroutine development based on an Eulerian-Eulerian approach for soot filtration visualization in a three-dimensional particulate filter model
A three-dimensional model is developed for computational fluid dynamics analysis of soot filtration processes in a wall flow–type particulate filter based on an Eulerian–Eulerian numerical approach. The primary objective of this study is to accurately capture the local values of filtration parameters, such as volume porosity, collection efficiency, and soot mass deposited, through i...
Replacing target setting by value models in the 'house of quality' for value-based requirements specifications
Setting targets for engineering characteristics is common practice in the ‘house of quality’ for establishing requirements specifications. However, if deployed arbitrarily, this practice is prone to errors and can often yield irrational results. Three potential methodological problems have been identified, regarding the setting of independent targets for each engineering characteris...