Search results

Two‐dimensional free convective flow in a parallelogram‐shaped enclosure has been studied numerically. The heated and cooled walls of the enclosure are isothermal and inclined at an angle β with respect to gravity. The top and bottom walls of the enclosure are horizontal and adiabatic. Calculations have been made for Rayleigh numbers ranging from 10³ to 10⁵ for a variety of wall angles (60° ≤ β ≤60° ) and enclosure aspect ratios 0.5 ≤ A ≤ 3. Average and local Nusselt number results are presented for a Prandtl number of 0.7. Streamline and isotherm contours are also presented.

The purpose of this paper is to carry out a comprehensive review of some latest studies devoted to natural convection phenomenon in the enclosures because of its significant industrial applications.

Geometries of the enclosures have considerable influences on the heat transfer which will be important in energy consumption. The most useful geometries in engineering fields are treated in this literature, and their effects on the fluid flow and heat transfer are presented.

A great variety of geometries included with different physical and thermal boundary conditions, heat sources and fluid/nanofluid media are analyzed. Moreover, the results of different types of methods including experimental, analytical and numerical are obtained. Different natures of natural convection phenomenon including laminar, steady-state and transient, turbulent are covered. Overall, the present review enhances the insight of researchers into choosing the best geometry for thermal process.

A comprehensive review on the most practical geometries in the industrial application is performed.

A two‐spar cantilever box beam with forty‐five degrees sweep and oblique ribs placed parallel to the root clamping section was the subject of a series of static tests. Stress and strain distributions were determined, primarily in a region distant from the root and tip disturbances, to permit a stringent comparison with three well‐known swept wing theories and the simple theory of bending. Torsional and flexural stiffnesses were also measured and compared with these theories. The sequence of calculation for each method is presented and it is found that two of the theories provide accurate predictions of the stresses, strains and stiffnesses. The influence of rivet slip and rivet flexibility on the stiffnesses of the box is mentioned. As a secondary aim of the investigation, the distribution of normal and shear strain has been measured in the cover skin and spar webs at the root connexion. The design of swept box examined has been the subject of research in a number of establishments and a review of this other work is included.

The paper aims to focus on a vision-based approach to advance the automated process of the manufacturing of an Airbus A350’s pressure bulkhead. The setup enables automated deformation and draping of a fiber textile on a form-variable end-effector.

The proposed method uses the information of infrared (IR) and color-based images in Red, Green and Blue (RGB) representative format, as well as depth measurements to identify the wrinkles and boundary edge of semi-finished dry fiber products on the double-curved surface of a flexible modular gripper used for laying the fabric. The technique implements a simple and practical image processing solution using a sequence of pixel-wise binary masks on an industrial scale setup; it bridges the gap between laboratory experiments and real-world execution, thereby demonstrating practical and applied research.

The efficacy of the technique is demonstrated via experiments in the presented work. The two objectives as follows boundary edge detection and wrinkle detection are accomplished in real time in an industrial setup.

During the draping process, tensions developed in the fibers of the textile cause wrinkles on the surface, which are highly detrimental to the production process, material quality and strength. The proposed method automates the identification and detection of the wrinkles and the textile on the gripper surface. The proposed work aids in alleviating the problems caused by these wrinkles and helps in quality control in the production process.

The purpose of this study was to categorize the whole body shapes of overweight and obese females in the US and examine apparel fit based on the current ASTM sizing standards related to the body shapes categorized.

Body scan data from 2,672 subjects were used. To categorize their whole body shapes using 97 body measurements, principal component analysis with varimax rotation, a hierarchical cluster analysis and K-means cluster analysis were used. To compare the ASTM sizing standards for plus sizes (curvy and straight) and missy sizes (curvy and straight), five body parts (bust, under bust, waist, top hip, hip) using the formula for fit tolerance (measurement plus half of the interval) were compared with the ASTM sizing standards to determine the size appropriate for each body part.

Five whole body shapes among overweight and obese females in the US were categorized: Rectangle-curvy; parallelogram-moderately curvy; parallelogram-hip tilt; inverted trapezoid-moderately curvy and inverted trapezoid-hip tilt. When the body measurements in each body shape were compared with the current ASTM sizing systems for both misses and plus sizes, four-fifths or more of overweight and obese female adults in the US would find it difficult to obtain a perfect fit for both tops and bottoms.

Identifying whole body shapes among overweight and obese women in the US contributes significantly, as it will help apparel companies that target the markets of larger women develop a new sizing system. This study is the first attempt to analyze fit by comparing the ASTM sizing charts with body measurements in each body shape group. Further, the study contributes to the body-related literature by filling gaps in missing whole BS categories among overweight and obese females.

The construction of windscreen panels for modern aircraft is described and the role of each component in meeting the requirements for pressure strength, bird resistance and optical performance is discussed. The influence of the physical properties of the windscreen components on the performance of complete laminated windscreens is discussed and the limitations imposed by these properties indicated. Silicone inter‐layers are beginning to replace polyvinyl butyral inter‐layers in high‐speed aircraft laminated transparencies when the temperatures reached are above the working limit of the conventional interlayers. New types of glass capable of withstanding prolonged exposure to higher temperatures than soda lime silica glass without loss of toughening stress, and also capable of withstanding more severe thermal shock without fracture, have been developed.

The purpose of this paper is to model mixed convection in a square cavity included circular cylinders motion using an incompressible smoothed particle hydrodynamics (ISPH) technique.

The problem is solved numerically by using the ISPH method.

The SPH tool shows robust performance to simulate the rigid body motion in the mixed convective flow with heat transfer, and it may apply easily to complicated problems in 2D and 3D problem without difficulties.

The application of the SPH method to mixed convective flow with heat transfer and its potential application easily to complicated 3D problems is original.

Purpose – This paper examines Hayek's view of the mind to see if it provides a useful and unifying foundation for understanding both deliberative choices that involve conscious information processing (the ‘economic imagination’) and choices that are not determined by conscious processes such as those involving ‘gut feelings’ or knowledge that the chooser is unable to articulate (the ‘tacit dimension’).

Methodology/approach – The paper analyses Hayek's view of the mind from the standpoint of evolutionary economics and biology. Because of the significance of pattern detection in Hayek's analysis, the paper examines parallels with key ideas in personal construct psychology and artificial intelligence. As well as exploring the evolutionary advantages of behavior based on programmed responses to the detection of particular patterns, it also explores possible evolutionary and neural origins of dysfunctional heuristics and biases.

Findings – Hayek's theory of the mind provides useful foundations for analyzing choice in a evolving, pluralistic and context-based manner rather than seeing all choices as made in much the same way on the basis of ‘given preferences’ that obey the axioms of rational choice theory. His theory complements work in psychological economics based on Kelly's personal construct psychology, cognitive dissonance theory and Maslow's hierarchy of needs. The analysis leads to questions being raised about the conventional faith in the notion of a diminishing marginal rate of substitution.

Originality/value of paper – The paper shows how very different ways of choosing can be understood in terms of Hayek's analysis of the mind.

The purpose of this study is to carry out a comprehensive analysis of magneto-hydrodynamics (MHD), nanofluidic flow dynamics and heat transfer as well as thermodynamic irreversibility, within a novel butterfly-shaped cavity. Gaining a thorough understanding of these phenomena will help to facilitate the design and optimization of thermal systems with complex geometries under magnetic fields in diverse applications.

To achieve the objective, the finite element method is used to solve the governing equations of the problem. The effects of various controlling parameters such as butterfly-shaped triangle vertex angle (T), Rayleigh number (Ra), Hartmann number (Ha) and magnetic field inclination angle (γ ) on the hydrothermal performance are analyzed meticulously. By investigating the effects of these parameters, the authors contribute to the existing knowledge by shedding light on their influence on heat and fluid transport within butterfly-shaped cavities.

The major findings of this study reveal that the geometrical shape significantly alters fluid motion, heat transfer and irreversibility production. Maximum heat transfer, as well as entropy generation, occurs when the Rayleigh number reaches its maximum, the Hartmann number is minimized and the angle of the magnetic field is set to 30° or 150°, while the butterfly wings angle or vertex angle is kept at a maximum of 120°. The intensity of the magnetic field significantly controls the heat flow dynamics, with higher magnetic field strength causing a reduction in the flow strength as well as heat transfer. This configuration optimizes the heat transfer characteristics in the system.

Further research can be expanded on this study by examining thermal performance under different curvature effects, orientations, boundary conditions and additional factors. This can be accomplished through numerical simulations or experimental investigations under various multiphysical scenarios.

The geometric configurations explored in this research have practical applications in various engineering fields, including heat exchangers, crystallization processes, microelectronic devices, energy storage systems, mixing processes, food processing, air-conditioning, filtration and more.

This study brings value by exploring a novel geometric configuration comprising the nanofluidic flow, and MHD effect, providing insights and potential innovations in the field of thermal fluid dynamics. The findings contribute a lot toward maximizing thermal performance in diverse fields of applications. The comparison of different hydrothermal behavior and thermodynamic entropy production under the varying geometric configuration adds novelty to this study.

An expression for the efficiency of a subject catalogue or index is derived from the probability of success when using the catalogue, and the cost of making and using the catalogue, compared with the cost of finding material in the library stock when no subject catalogue is available.