The aim of this experimental study is to determine the heat transfer coefficients in laminar regime of mechanically agitated vessel for Newtonian (water) and non-Newtonian fluids, i.e. CMC (carboxy methyl cellulose) solutions in mechanically agitated vessel. It is found that Dean number and Prandtl number play an important role with Nusselt number while determining heat transfer coefficients. Modified

Use of environmentally safe refrigerants is the need of the hour to minimize the carbon footprints and to reduce the ozone depletion. The application of such environmentally safe refrigerants in the thermosyphon with the micro/nanoporous coating is expected to operate efficiently. In this study, a simple cost-effective anodizing technique to form a uniform thin micro/nanoporous coating at the inner

In the present article, we intend to study quasi-analytically the unsteady three-dimensional squeezed flow of the magnetite–graphene oxide/water hybrid nanofluid inside a rotating channel with two horizontal and parallel sheets, in which the lower sheet is stationary, stretchable, and permeable, while the upper sheet is moving and impermeable. Our methodology is based on the single-phase Tiwari–Das

The solar irradiance received by the solar cell is partially lost as heat, which carries negative effect on its voltage and in turn, its generated power. This trapped heat within the photovoltaic module is considered waste energy. Hence, techniques to extract this heat to utilize it for thermal loads, such as water heating or drying, are presented throughout the literature. Most prominent technique

Based on the elastohydrodynamic theory, the nonlinear dynamic behavior of worn oil-lubricated rolling bearings is explored, and the dynamic response including the effect of trajectory of the axis center, the accelerated speed, and the film thickness is analyzed. The worn model is represented by the worn depth. The discrete iterative method and implicit Euler method are combined to solve the dynamic

In this paper, a new manufacturing method of pyramidal lattice cells has been suggested to produce lattice composite cylinders. Moreover, the effect of fiber volume fraction, vacuum molding, and fiber pre-tension has been investigated on the load-carrying capacity of the cylindrical pyramidal lattice structure of a carbon fiber composite. The carbon fiber composite cylindrical pyramidal lattice structure

The present paper is concerned to study the influence of second-order slip, mixed convection, viscous and Joule dissipations, thermophoretic and Brownian diffusions on steady stagnation point nanofluid flow over a stretching sheet embedded in a porous medium with passive control of nanoparticles. Graphs for velocity, temperature and concentration of present nanofluid flow model, obtained by using spectral

This study deals with the launch time of main characteristic of NH3-H 2O absorption chiller under different working condition. The aim of this work was about to scrutinize a lumped-parameter dynamic simulation of aqua-ammonia absorption chiller in addition to investigating the effect of subcooled liquid at condenser/absorber outlet on absorption chiller’s key parameters launch time. Also, the effect

The axial self-infeed rolling process is an advanced and efficient process to form long threads such as lead screw and thread shaft. The experiments of axial self-infeed rolling process for the stainless steel were conducted with three blank diameters, forming speeds and two lubrication conditions. The effects of forming speed, blank diameter and lubrication condition on forming torque, microhardness

Rotary kiln reactors play an important role in improving the mechanical properties and usability of basic oxygen furnace slag through a carbonation process. The performance of such reactors is critically dependent on the residence time of the CO2 gas used to promote the carbonation reaction. Accordingly, the present study proposes a rotary kiln reactor in which the residence time is increased by arranging

Although significant advances have been made in tandem-blade technology for axial and centrifugal compressors, little attention has been paid to its application in centrifugal pumps. In this study, we propose a new tandem-blade design method for improving inner flow characteristics and overall performance of a centrifugal pump. With the SST k − ω turbulence model, three-dimensional turbulent flow fields

A geometrical mass control loop is proposed in this research to use in the level set method in order to simulation of multiphase flows with complex topologies of the interface and a case study is investigated using proposed scheme. In this regard oblique interaction and coalescence of bubbles in a liquid is investigated. The level set method is suffering from poor mass conservation in the case of severe

This study investigates novel vermiculite–calcium chloride composite solid desiccant material for desiccant-assisted evaporative cooling applications. In addition, comparative performance analyses between direct and desiccant-assisted evaporative cooling were performed. According to the study results, temperature drop around 10 ℃ with an average cooling rate of 700 W and coefficient of performance

In the present paper, two configurations of structured reactors (with and without) chimney tray placed below the packed bed have been investigated to study their effect on maldistribution factor and pressure drop characteristics. A simulation result based on a three-dimensional computational fluid dynamics was involved using ANSYS Fluent. First, maldistribution factors without chimney tray were calculated

This study deals with designing a decentralized multi-input multi-output controller board based on a low-cost microcontroller, which drives both parts of variable-speed scroll compressor and electronic-type expansion valve simultaneously in a chiller system. This study aims to show the applicability of commercial low-cost microcontroller to increase the efficiency of the chiller system, having variable-speed

The unreasonable dynamic characteristics results in decrease of screening efficiency of the vibrating screen. However, the synchronous behavior of motors is key factor to determine dynamic characteristics of the screens. In this paper, two unbalanced rotors actuated with motors in a three-dimensional space are proposed. To understand the synchronous mechanism, the dynamic equation of the system is

Enhancement of heat transfer is very important in many engineering applications. The present study explores one of such possibilities by increasing the surface area of a plane wall. The effect of wavy wall on thermal and flow characteristics of a turbulent wall jet is studied in detail. The amplitude of the wavy surface is varied between 0.1 and 0.7 with an interval of 0.1. The Reynolds number is set

Application of ice cold energy storage (ICES) is for reducing power consumption in air-conditioning systems. ICES systems have two full and partial operating modes. Partial operating mode of ICES system is modeled here at two demand limiting (POM-DL) and load leveling (POM-LL) conditions. After energy, exergy, and economic and environmental modeling/analysis of POM-DL and POM-LL, multi-objective (exergy

Twin-screw compressors are often used for generating compressed fluids useful for various industrial applications, thereby necessitating the need for evolving energy efficient designs. In the past few decades, several experimental studies were conducted to understand the phenomenon inside the twin-screw compressor, thereby leading to performance improvement and design optimization. The present study

Usually solid fins are used in industrial heating as well as cooling systems. Installing porous fins in heat exchangers and process cooling equipments like chillers can significantly improve the heat transfer ability of the equipments. This happens due to the increase in effective thermal conductivity as a result of the increase in surface area for convection through pores. The theory of porous media

Usually solid fins are used in industrial heating as well as cooling systems. Installing porous fins in heat exchangers and process cooling equipments like chillers can significantly improve the heat transfer ability of the equipments. This happens due to the increase in effective thermal conductivity as a result of the increase in surface area for convection through pores. The theory of porous media

As the core component of screw compressors, the rotor profile projected by a screw rotor on the rotor's end face is one of the most important parts of twin-screw compressors to study. The performance of the designed rotor profile directly affects the efficiency, accuracy, and service life of twin-screw compressors. The key to design and machine the rotors is to efficiently and highly accurately overcome

As the core component of screw compressors, the rotor profile projected by a screw rotor on the rotor's end face is one of the most important parts of twin-screw compressors to study. The performance of the designed rotor profile directly affects the efficiency, accuracy, and service life of twin-screw compressors. The key to design and machine the rotors is to efficiently and highly accurately overcome

The complexity and importance of an efficient maintenance strategy is widely recognized in today's competitive market. Industrial organizations are continuously seeking new maintenance strategies to improve the effectiveness of their operations.1 Maintenance has evolved over time as advancement in technology and fast growing research has been put into building more efficient and reliable systems.2

The complexity and importance of an efficient maintenance strategy is widely recognized in today's competitive market. Industrial organizations are continuously seeking new maintenance strategies to improve the effectiveness of their operations.1 Maintenance has evolved over time as advancement in technology and fast growing research has been put into building more efficient and reliable systems.2

In construction and mining equipment that are subjected to large variation in load, the valve controlled hydro-motor drives are commonly used. The said drive is usually in open-loop configuration where by controlling the valve, the variable flow is supplied to the actuator to regulate its rotational speed. The performance of such valve is almost same as that of the servo-valve; however, it is less

In construction and mining equipment that are subjected to large variation in load, the valve controlled hydro-motor drives are commonly used. The said drive is usually in open-loop configuration where by controlling the valve, the variable flow is supplied to the actuator to regulate its rotational speed. The performance of such valve is almost same as that of the servo-valve; however, it is less

Claw couplings generally connect two axes and facilitate torque transmission using gear teeth, and are available with a variety of gear teeth shapes. Among these, Curvic couplings are widely used in heavy-duty gas turbines and the aeroengine industry because of the special shape of their teeth and attributes such as reliable positioning, precise centering, excellent structural stability, strong load

Claw couplings generally connect two axes and facilitate torque transmission using gear teeth, and are available with a variety of gear teeth shapes. Among these, Curvic couplings are widely used in heavy-duty gas turbines and the aeroengine industry because of the special shape of their teeth and attributes such as reliable positioning, precise centering, excellent structural stability, strong load

With the increasing number of global automobiles, energy crisis and environmental pollution have become the bottleneck issues restricting the development of global automobile industry. The “Made in China 2025” plan clearly points out that “new energy vehicle” – the automobile with electric propulsion link – is one of the 10 key development industries in the future. Therefore, the research and development

With the increasing number of global automobiles, energy crisis and environmental pollution have become the bottleneck issues restricting the development of global automobile industry. The “Made in China 2025” plan clearly points out that “new energy vehicle” – the automobile with electric propulsion link – is one of the 10 key development industries in the future. Therefore, the research and development

Reciprocating compressors are widely used in the fields of petrochemistry and metallurgy. The design scheme for the compressor system must meet the demands of the highest operational power and flow; however, most of the actual operational states of the compressor are lower than the design state. Therefore, a stepless capacity method that functions through delayed closure of the suction valve has been

Reciprocating compressors are widely used in the fields of petrochemistry and metallurgy. The design scheme for the compressor system must meet the demands of the highest operational power and flow; however, most of the actual operational states of the compressor are lower than the design state. Therefore, a stepless capacity method that functions through delayed closure of the suction valve has been

Microfluidics technology has been applied to different chemical and biological applications of lab-on-a-chip (LOC) devices including medical diagnostics, drug development etc. A LOC device needs to be compact, miniatured requiring a small concentration of reagents for analysis. Microfluidic devices range from ten to several hundred micrometers in characteristic dimension. These devices are formed by

Microfluidics technology has been applied to different chemical and biological applications of lab-on-a-chip (LOC) devices including medical diagnostics, drug development etc. A LOC device needs to be compact, miniatured requiring a small concentration of reagents for analysis. Microfluidic devices range from ten to several hundred micrometers in characteristic dimension. These devices are formed by

Electronic devices have become a crucial part of our life. From huge prime movers to small gadgets, everything is electronically driven. The trend from quite some time has been on the miniaturization of these devices and the increase of their power density. Along with that, we also have to keep their temperature below some critical value or else they would become inefficient and unreliable. Fluctuating

Electronic devices have become a crucial part of our life. From huge prime movers to small gadgets, everything is electronically driven. The trend from quite some time has been on the miniaturization of these devices and the increase of their power density. Along with that, we also have to keep their temperature below some critical value or else they would become inefficient and unreliable. Fluctuating

The first issue of the Journal of Mechanical Engineering Science (JMES) was published in June 1959 to provide a forum for specialised and scientific contributions in mechanical engineering. The development of the journal over its first 50 years was described in an editorial by Professor Duncan Dowson in 2009. In January 2019, I introduced our 60th anniversary with an editorial describing more recent

The growing demand for higher power generation brings the request for increased reliability and efficiency of turbines. The last stage blades in the low-pressure steam turbine parts (LP) are, from this point of view, a key element of the turbine design defining the overall power, dimensions and design of the machine. Therefore, longer and bigger blades are designed.1 However, these large blades are

Gas turbine bladed disks are subjected to high levels of periodic excitation, which can lead to resonant vibration of blades within the operating range, resulting in large stresses that may cause high cycle fatigue (HCF).1 To accurately predict the vibration amplitude, and therefore the fatigue life of the components, the damping effect of friction forces at contact interfaces such as blade roots,

Stochastic resonance is the nonmonotonic response of a system to stochastic excitation. Although this phenomenon is well known in signal processing technology, it is often perceived as paradoxical, because it contradicts the intuition that has been developed by the analysis of conventional linear systems where the ratio of the output signal-to-noise is the maximum in the absence of noise. Numerous

Superharmonic resonances of the periodic vibrations are observed in many nonlinear dynamical systems. The multiple scales method is used to analyze the superharmonic forced vibrations of nonlinear systems in asymptotic limit.1 The superharmonic resonances of the circular plate forced vibrations are analyzed by Srirangarajan.2 The longitudinal-transverse superharmonic shaft vibrations are described

The analysis of the propagation of waves in structures is a fundamental task in many engineering applications. The knowledge of dispersion relations, providing information on the type and nature of propagating waves is of interest for the prediction of forced response, acoustic radiation, nondestructive testing, and transmission of structure-borne sound. All these themes are nowadays the subject of

Free cutting steels, which are commonly used in many mass production fields, such as the automotive industry and household appliances, contain sulfur, lead, and some other elements, which promote machinability. For this reason, this class of materials is widely used in lock industries, which are characterized by very large production batches in order to cut production costs. It must be observed that

Stationary ergodic Gaussian random data have been the convenient basis of many of the data used for the development of models for the analysis of random vibration fatigue problems especially using spectral-based methods.1–5 It is, however, known that non-Gaussian excitations occur due to road irregularities in automobiles and turbulent pressure flections in the aerospace sector.6,7 Highly non-Gaussian

Damage identification attracts wide attention and in-depth research in numerous engineering fields for its paramount importance for systems safety and operational assessment. Among the proposed techniques, structural vibration-based ones are increasingly considered. There are two main reasons behind this progression: a practical motivation, related to the aptitude of dynamic tests in capturing the

Due to outdoor exposure, photovoltaic (PV) modules are subjected to degradation phenomena during their expected lifetime (20–25 years). Producer warranties claim power losses lower than 10% of the initial nominal power during the first 10–12 years, and up to 20% after 20–25 years of operation, with different power loss rates.1 Many external sources of stress, like solar radiation, wind, high temperature

Aerodynamic development and testing have become fundamental to successful motorsport and road vehicle programs. The aerodynamic development of the vehicle is fully integrated within the complete design cycle. A mix of development techniques are used throughout the process, where the exact selection of the development tool depends on many factors ranging from performance to accessibility and economics

As the world economy continues to grow, energy demand is likely to increase despite efforts to increase the efficiency of energy use. The urgent need to meet this increasing demand and to reduce greenhouse gas emissions is being met, at least in part, by the development of large-scale wind turbines, both onshore and offshore. Nevertheless, for some situations including urban centres and off-grid locations

The immersed boundary method (IBM), first developed by Professor Peskin,1 is a methodology for dealing with boundary conditions at interfaces (including fluid–fluid and fluid–solid ones) based on meshes that do not conform to the shapes of the immersed boundaries or interfaces. The advantages of the IBM are manifold: the mesh generation is very easy even for complicated geometries; mesh movement and

For every complex problem there is a solution that is simple, neat and wrong. – H. L. Mencken

In recent years, continuum robots mimicking biological structures such as octopus tentacles and elephant trunks have gained increasing attention due to their unique structural advantages of inherent compliance and adaptability. This enables them to be suitable for operations in narrow, complex, and unconstructed environments such as detection, rescue, and medical fields.1

The origin and early evolution of birds and avian flight is one of the most discussed topics in palaeontology. Two years after Darwin’s celebrated book On the Origin of Species, one of the major clues for understanding the origin of birds was already discovered in Upper Jurassic limestones from Bavaria in Germany.1,2 The skeleton of Archaeopteryx is characterized by a mosaic of “reptilian” (teeth,