Flowfield-dependent variant method for moving-boundary problems

A novel numerical scheme using the combination of flowfield-dependent variation method and arbitrary Lagrangian–Eulerian method is developed. This method is a mixed explicit–implicit numerical scheme, and its implicitness is dependent on the physical properties of the flowfield. The scheme is discretized using the finite-volume method to give flexibility in dealing with complicated geometries. The formulation itself yields a sparse matrix, which can be solved by using any iterative algorithm. Several benchmark problems in two-dimensional inviscid and viscous flow have been selected to validate the method. Good agreement with available experimental and numerical data in the literature has been obtained, thus showing its promising application in complex fluid–structure interaction problems

Numerical Simulation of the Interaction between Slender Body Vortices and a Fin

The interaction between slender body vortices and a single fin located down the axis of the body is investigated numerically for angle of attack of 30 deg. and Reynolds number of 6000. The present research includes a parametric study on the effects of fin axial and azimuthal positions on the development of the vortex system. A numerical method based on the pseudo-compressibility is used for solving the three-dimensional incompressible Navier-Stokes equations using Lower-Upper Symmetric Gauss-Seidel implicit scheme. The numerical results show that the vortices remain very coherent and attached to the body until they reach the fin section where they become less coherent and begin to separate from the body. Also, the result shows that the fin location does not affect the upstream development of the vortices but it does affect the location at which the vortices separate from the body. The effect of azimuthal fin positions was also investigated. As azimuthal angle of the fin increased, the size of the vortex on the port side decreased, but the starboard side vortex grew in size and moved across the leeward ray to the port side. The computed results are found to agree well with the experimental data

Evaluation of the Contents of the Five Stars Hotel Website and Customer Orientation

The objectives of this study are multifold: to investigate the functionality of hotel websites through a content review and to gauge customer perceptions of the value of hotel website design. To conduct the study, hotel websites were combed for numerical and visual information. Providers of information are evaluated based on their unique and comprehensive expertise measurements. The research is based on two key components: a report on all 37 five-star hotels in Jordan that analyzes their website layout in terms of population, and a survey of 100 hotel guests to ascertain how they interpret hotel websites. This proposed study is the first of its kind, with the objective of establishing a methodology for evaluating all hotel measurements provided by hotel websites. The following are the findings: When the independent variable (marketing orientation) has a value of T = 7.519, the coefficient of simple linear regression has statistical significance (Customer Orientation). The fact that Aqaba Zone Advertising and Customer Oriented Classified Hotels have a statistically significant effect on their categorization is acknowledged, as Aqaba Zone Advertising and Customer Oriented Classified Hotels have a significant effect on the coefficient of simple linear regression equation (0.605). As a result, hotel management may employ a specific predictive evaluation model to analyze their hotels websites from two perspectives: that of the management team and that of the consumers. For the first time, this analysis brings together claims from both perspectives (hotel managers and clients)

Human Activity and Motion Pattern Recognition within Indoor Environment Using Convolutional Neural Networks Clustering and Naive Bayes Classification Algorithms

Human Activity Recognition (HAR) systems are designed to read sensor data and analyse it to classify any detected movement and respond accordingly. However, there is a need for more responsive and near real-time systems to distinguish between false and true alarms. To accurately determine alarm triggers, the motion pattern of legitimate users need to be stored over a certain period and used to train the system to recognise features associated with their movements. This training process is followed by a testing cycle that uses actual data of different patterns of activity that are either similar or different to the training data set. This paper evaluates the use of a combined Convolutional Neural Network (CNN) and Naive Bayes for accuracy and robustness to correctly identify true alarm triggers in the form of a buzzer sound for example. It shows that pattern recognition can be achieved using either of the two approaches, even when a partial motion pattern is derived as a subset out of a full-motion path

Study of Dynamic Interaction Between Low Re Aerodynamic Load and Flexible-Biomimetic Wings with Tailorable Stiffness by FSI Modeling

In the present work, we investigate dynamic interaction and response of flexible bio-inspired morphing wing structure to a low Reynolds aerodynamic load. The aspects of inspiration are as follows. First, the segmentation of the wing into rigid and flexible segments. Considering a leading edge constitution of bone and muscle. In addition to a flexible trailing edge composed of feathers. Second, the material properties provided by experimental biology in literature are adopted such as the bending stiffness and Young's modulus. The development of numerical models allowing non uniform distribution of properties are developed and implemented into an OpenFoam finite volume solver that couples fluid dynamics to a structural solid dynamics solver through the FSI interface. In the course of this work, the validation is performed for a NACA6409 airfoil considering a rigid segment of 40\% and flexible segment 60\% chord length in order to test the aero-structure behavior for an aerodynamic load of air flow at low Reynolds number of $\boldsymbol{5\times 10^5}$ for the fluid and feather inspired material properties. The results suggest that bio-inspired techniques can be reproduced in engineering configurations.Comment: This is the author's version of an article that has been published at 2023 AIAA SciTech Forum - 23-27 January 2023. The final version of record is available at: \url{https://arc.aiaa.org/doi/abs/10.2514/6.2023-0826

Experimental investigation of plain- and flapped-wing tip vortices

Particle image velocimetry was used in a low-speed wind tunnel to investigate and characterize wing tip vortex structures. A rectangular wing of a subsonic wall interference model was used as a vortex generator in two different configurations: 1) plain wing and 2) flapped wing with the trailing-edge flap extended at 20 degrees. Vortex flow quantities and their dependence on angle of attack at Reynolds numbers of 32:8 � 103 and 43:8 � 103 were evaluated. Assessment of measured data reveals that the peak values of tangential velocities, vortex strength, and vorticities are directly proportional to the angle of attack. The vortex core radius value grows slowly as the angle of attack is increased. Both plain and flapped configurations showed similar trends. The peak tangential velocities and circulation almost doubled when the flapped configuration was used instead of the plain wing

REVIEW OF PASSIVE DRAG REDUCTION TECHNIQUES FOR BLUFF ROAD VEHICLES

ABSTRACT:This paper presents a review of the techniques used to reduce aerodynamic drag over bluff bodies such as cylinders, spheres, 2D bodies with blunt backs and their application to commercial road vehicles.  The recent research carried out on the drag reduction is presented and categorised. A new classification of the techniques is introduced and major contributions under them are shown. It can be concluded that there is not much work done with realistic 3D bluff bodies, especially using passive methods. ABSTRAK: Kertas kerja ini membentangkan kaji selidik semula teknik yang digunakan untuk mengurangkan seret aerodinamik ke atas jasad tubir seperti silinder, sfera, jasad 2D dengan belakang tumpul dan aplikasinya terhadap kenderaan jalan raya komersial. Pengurangan seretan dibentangkan dan dikategorikan dengan kajian terkini. Klasifikasi teknik terkini diperkenalkan dan sumbangan utamanya diperbentangkan.  Secara kesimpulannya terdapat banyak tugasan yang tidak yang dapat dijalankan dengan menggunakan jasad tubir 3D sebenar, terutamanya dengan penggunaan kaedah pasif

La relación entre la calidad del servicio, la satisfacción del cliente, el valor percibido y la fidelidad del cliente: un estudio de caso de Fly Emirates

Client loyalty is one of the biggest challenges for the airline industry and marketers are seeking information on how to build client loyalty. This study will explore the relationship between service quality, client satisfaction, perceived value and client loyalty in the airline industry. The purpose of this study is to develop and implement a method for airline to identify attributes that will increase client loyalty. 384 respondents participate in this study and questionnaires were distributed randomly to passengers traveling by Emirates. In particularly a deductive approach adapted to collect specific quantitative information to accept or reject the hypothesis. Current study applies Structural Equation Modeling SEM-PLS to investigate the relationship among the constructs in proposed model. This study found that service quality has appositive relationship on passengers’ satisfaction and client loyalty and negative relationship on perceived value and client loyalty. The results of this study indicated that service quality and passenger's satisfaction are important factors effect of client loyalty. In conclusion Emirates must be able to understand the importance of service quality and passenger's satisfaction to fulfill the client loyalty and improve the service quality that make most significant in airline industry.La lealtad del cliente es uno de los mayores desafíos para la industria de las aerolíneas. Por eso, los profesionales de marketing están buscando información sobre cómo desarrollar la lealtad del cliente. Este estudio explorará la relación entre la calidad del servicio, la satisfacción del cliente, el valor percibido y la lealtad del cliente en la industria aérea. El propósito de este estudio es desarrollar e implementar un método para que la aerolínea identifique atributos que aumentarán la lealtad del cliente. Unos 384 encuestados participan en este estudio y los cuestionarios se distribuyeron al azar entre los pasajeros que viajaban en Fly Emirates. En particular, un enfoque deductivo adaptado para recopilar información cuantitativa específica para aceptar o rechazar la hipótesis. El estudio actual aplica el modelo de ecuación estructural SEM-PLS para investigar la relación entre los constructos en el modelo propuesto. Este estudio encontró que la calidad del servicio tiene una relación positiva en la satisfacción de los pasajeros y la lealtad del cliente. Por otro lado tiene una relación negativa en el valor percibido y la lealtad del cliente. Los resultados de este estudio indicaron que la calidad del servicio y la satisfacción del pasajero son factores importantes que afectan a la lealtad del cliente. En conclusión, Fly Emirates debe ser capaz de comprender la importancia de la calidad del servicio y la satisfacción del pasajero para cumplir con la lealtad del cliente y mejorar la calidad del servicio que es más importante en la industria de las aerolíneas

Efficient power control framework for small-cell heterogeneous networks

Heterogeneous networks are rapidly emerging as one of the key enablers of beyond fifth-generation (5G) wireless networks. It is gradually becoming clear to the network operators that existing cellular networks may not be able to support the traffic demands of the future. Thus, there is an upsurge in the interest of efficiently deploying small-cell networks for accommodating a growing number of user equipment (UEs). This work further extends the state-of-the-art by proposing an optimization framework for reducing the power consumption of small-cell base stations (BSs). Specifically, a novel algorithm has been proposed which dynamically switches off the redundant small-cell BSs based on the traffic demands of the network. Due to the dynamicity of the formulated problem, a new UE admission control policy has been presented when the problem becomes infeasible to solve. To validate the effectiveness of the proposed solution, the simulation results are compared with conventional techniques. It is shown that the proposed power control solution outperforms the conventional approaches both in terms of accommodating more UEs and reducing power consumption.publishe