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Article
Publication date: 3 January 2017

Shuyuan Liu and Tat L. Chan

The purpose of this paper is to study the complex aerosol dynamic processes by using this newly developed stochastically weighted operator splitting Monte Carlo (SWOSMC) method.

Abstract

Purpose

The purpose of this paper is to study the complex aerosol dynamic processes by using this newly developed stochastically weighted operator splitting Monte Carlo (SWOSMC) method.

Design/methodology/approach

Stochastically weighted particle method and operator splitting method are coupled to formulate the SWOSMC method for the numerical simulation of particle-fluid systems undergoing the complex simultaneous processes.

Findings

This SWOSMC method is first validated by comparing its numerical simulation results of constant rate coagulation and linear rate condensation with the corresponding analytical solutions. Coagulation and nucleation cases are further studied whose results are compared with the sectional method in excellent agreement. This SWOSMC method has also demonstrated its high numerical simulation capability when used to deal with simultaneous aerosol dynamic processes including coagulation, nucleation and condensation.

Originality/value

There always exists conflict and tradeoffs between computational cost and accuracy for Monte Carlo-based methods for the numerical simulation of aerosol dynamics. The operator splitting method has been widely used in solving complex partial differential equations, while the stochastic-weighted particle method has been commonly used in numerical simulation of aerosol dynamics. However, the integration of these two methods has not been well investigated.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 20 January 2012

Iftikhar H. Makhdoom and Qin Shi‐Yin

The purpose of this paper is to propose a new algorithm for in‐mission trajectories and speed adjustment of multiple unmanned aerial vehicles (UAVs) participating in a mission…

Abstract

Purpose

The purpose of this paper is to propose a new algorithm for in‐mission trajectories and speed adjustment of multiple unmanned aerial vehicles (UAVs) participating in a mission that requires them to arrive at target location simultaneously with switching and imperfect communication among the vehicles.

Design/methodology/approach

This algorithm, programmed at each UAV level, is based on the repeated consensus seeking among the participating vehicles about the time‐on‐target (ToT) through an imperfect inter‐vehicle communication link. The vehicles exchange their individual ToT values repeatedly for a particular duration to pick the highest value among all the vehicles in communication. A consensus confidence flag is set high when consensus is successful. After every consensus cycle with high confidence value, the mission adjustment is carried out by computing difference value between ToT consensus and a threshold value. For the difference values higher than a certain limit, vehicle's trajectory is adjusted by in‐mission insertion of new waypoint (WP) and for lower values the vehicle's speed is varied under allowable limits. The consensus seeking followed by the mission adjustment is repeated periodically to quash the imperfect communication effects.

Findings

A mathematical analysis has been carried out to establish the conditions for convergence of the algorithm. The simultaneous arrival of the vehicles subjected to switching communication is achieved only when the union of the switching links during the consensus period enables a vehicle to receive information from all the other vehicles and the switching rate is sufficiently high. This algorithm has been tested in a 6‐degree‐of‐freedom (DoF) multiple UAV simulation environment and achieves simultaneous arrival of multiple fixed wing UAVs under imperfect communication links that meets the aforementioned conditions.

Research limitations/implications

The presented algorithm and design strategy can be extended for other types of cooperative control missions where certain variable of interest is shared among all the vehicles over imperfect communication environment. The design is modular in functionality and can be incorporated into existing vehicles or simulations.

Originality/value

This research presents a new consensus algorithm that repeatedly performs polling of ToT among the vehicles through intermittent communication. The continual nature of consensus seeking covers the weakness of the imperfect communication. A two‐level mission adjustment provides better accuracy in simultaneous arrival at the target location.

Details

Aircraft Engineering and Aerospace Technology, vol. 84 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 1 April 1998

Bernd Kreuzer and Dragoslav Milojevic

Suppliers of industrial paint finishing lines usually have only a relatively short time in which to submit tenders for the lines and get them up and running. “Simultaneous…

Abstract

Suppliers of industrial paint finishing lines usually have only a relatively short time in which to submit tenders for the lines and get them up and running. “Simultaneous engineering” meets this need. Focuses on simulation software which allows the behaviour of projected installations as well as the associated physical and logistical processes to be examined in detail. Describes the 3D simulation system currently being used by ABB to determine object motion and material flow.

Details

Industrial Robot: An International Journal, vol. 25 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 7 March 2023

Metin Uzun and Tugrul Oktay

The purpose of this paper is to improve autonomous flight performance of an unmanned aerial vehicle (UAV) having actively sweep angle morphing wing using simultaneous UAV and…

Abstract

Purpose

The purpose of this paper is to improve autonomous flight performance of an unmanned aerial vehicle (UAV) having actively sweep angle morphing wing using simultaneous UAV and flight control system (FCS) design.

Design/methodology/approach

An UAV is remanufactured in the ISTE Unmanned Aerial Vehicle Laboratory. Its wing sweep angle can vary actively during flight. FCS parameters and wing sweep angle are simultaneously designed to optimize autonomous flight performance index using a stochastic optimization method called as simultaneous perturbation stochastic approximation (SPSA). Results obtained are applied for flight simulations.

Findings

Using simultaneous design process of an UAV having actively sweep angle morphing wing and FCS design, autonomous flight performance index is maximized.

Research limitations/implications

Authorization of Directorate General of Civil Aviation in Turkey is crucial for real-time UAV flights.

Practical implications

Simultaneous UAV having actively sweep angle morphing wing and FCS design process is so beneficial for recovering UAV autonomous flight performance index.

Social implications

Simultaneous UAV having actively sweep angle morphing wing and FCS design process achieves confidence, high autonomous performance index and simple service demands of UAV operators.

Originality/value

Composing a novel approach to improve autonomous flight performance index (e.g. less settling and rise time, less overshoot meanwhile trajectory tracking) of an UAV and creating an original procedure carrying out simultaneous UAV having actively sweep angle morphing wing and FCS design idea.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 7
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 30 November 2020

Sahin Akin, Oguzcan Ergun, Elif Surer and Ipek Gursel Dino

In performative architectural design, daylighting is a crucial design consideration; however, the evaluation of daylighting in the design process can be challenging. Immersive…

Abstract

Purpose

In performative architectural design, daylighting is a crucial design consideration; however, the evaluation of daylighting in the design process can be challenging. Immersive environments (IEs) can create a dynamic, multi-sensory, first-person view in computer-generated environments, and can improve designers' visual perception and awareness during performative design processes. This research addresses the need for interactive and integrated design tools for IEs toward better-performing architectural solutions in terms of daylighting illumination. In this context, building information modeling and performance simulations are identified as critical technologies to be integrated into performative architectural design.

Design/methodology/approach

This research adopts a design science research (DSR) methodology involving an iterative process of development, validation and improvement of a novel and immersive tool, HoloArch, that supports design development during daylighting-informed design processes. HoloArch was implemented in a game engine during a spiral software development process. HoloArch allows users to interact with, visualize, modify and explore architectural models. The evaluation is performed in two workshops and a user study. A hybrid approach that combines qualitative and quantitative data collection was adopted for evaluation. Qualitative data analyses involve interviews, while quantitative data analyses involve both daylighting simulations and questionnaires (e.g. technology acceptance model (TAM), presence and system usability scale (SUS)).

Findings

According to the questionnaire results, HoloArch had 92/100 for SUS, a mean value of 120.4 for presence questionnaire (PQ) and 9.4/10 for TAM. According to the simulation results, all participants improved the given building's daylighting performance using HoloArch. The interviews also indicated that HoloArch is an effective design tool in terms of augmented perception, continuous design processes, performative daylighting design and model interaction. However, challenges still remain regarding the complete integration of tools and simultaneous simulation visualization. The study concludes that IEs hold promising potentials where performative design actions at conceptual, spatial and architectural domains can take place interactively and simultaneously with immediate feedback.

Originality/value

The research integrates building information modeling (BIM), performative daylighting simulations and IEs in an interactive environment for the identification of potentials and limitations in performative architectural design. Different from existing immersive tools for architecture, HoloArch offers a continuous bidirectional workflow between BIM tools and IEs.

Details

Engineering, Construction and Architectural Management, vol. 28 no. 4
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 27 January 2023

Yongliang Wang and Nana Liu

The unstable dynamic propagation of multistage hydrofracturing fractures leads to uneven development of the fracture network and research on the mechanism controlling this…

Abstract

Purpose

The unstable dynamic propagation of multistage hydrofracturing fractures leads to uneven development of the fracture network and research on the mechanism controlling this phenomenon indicates that the stress shadow effects around the fractures are the main mechanism causing this behaviour. Further studies and simulations of the stress shadow effects are necessary to understand the controlling mechanism and evaluate the fracturing effect.

Design/methodology/approach

In the process of stress-dependent unstable dynamic propagation of fractures, there are both continuous stress fields and discontinuous fractures; therefore, in order to study the stress-dependent unstable dynamic propagation of multistage fracture networks, a series of continuum-discontinuum numerical methods and models are reviewed, including the well-developed extended finite element method, displacement discontinuity method, boundary element method and finite element-discrete element method.

Findings

The superposition of the surrounding stress field during fracture propagation causes different degrees of stress shadow effects between fractures and the main controlling factors of stress shadow effects are fracture initiation sequence, perforation cluster spacing and well spacing. The perforation cluster spacing varies with the initiation sequence, resulting in different stress shadow effects between fractures; for example, the smaller the perforation cluster spacing and well spacing are, the stronger the stress shadow effects are and the more seriously the fracture propagation inhibition arises. Moreover, as the spacing of perforation clusters and well spacing increases, the stress shadow effects decrease and the fracture propagation follows an almost straight pattern. In addition, the computed results of the dynamic distribution of stress-dependent unstable dynamic propagation of fractures under different stress fields are summarised.

Originality/value

A state-of-art review of stress shadow effects and continuum-discontinuum methods for stress-dependent unstable dynamic propagation of multiple hydraulic fractures are well summarized and analysed. This paper can provide a reference for those engaged in the research of unstable dynamic propagation of multiple hydraulic structures and have a comprehensive grasp of the research in this field.

Details

Engineering Computations, vol. 40 no. 1
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 30 July 2019

Sezer Çoban

The purpose of this paper is to rise the autonomous flight performance of the small unmanned aerial vehicle (UAV) using simultaneous tailplane of UAV and autopilot system design.

Abstract

Purpose

The purpose of this paper is to rise the autonomous flight performance of the small unmanned aerial vehicle (UAV) using simultaneous tailplane of UAV and autopilot system design.

Design/methodology/approach

A small UAV is remanufactured in the UAV laboratory. Its tailplane can be changed before the flight. Autopilot parameters and some parameters of tailplane are instantaneously designed to maximize autonomous flight performance using a stochastic optimization method. Results found are applied for simulations.

Findings

Benefitting simultaneous tailplane of UAV and autopilot system design process, autonomous flight performance is maximized.

Research limitations/implications

Authorization of Directorate General of Civil Aviation in Turkey is required for UAV flights.

Practical implications

Simultaneous tailplane and autopilot system design process is so useful for refining UAV autonomous flight performance.

Social implications

Simultaneous tailplane and autopilot system design process fulfills confidence, high autonomous performance, and easy service demands of UAV users. By that way, UAV users will be able to use better UAVs.

Originality/value

Creating a novel technique to recover autonomous flight performance (e.g. less overshoot, less settling time and less rise time during trajectory tracking) of UAV and developing a novel procedure performing simultaneous tailplane of UAV and autopilot system design idea.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 10
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 3 October 2016

Turgul Oktay, Mehmet Konar, Murat Onay, Murat Aydin and Mohamed Abdallah Mohamed

The purpose of this paper is to increase flight performance of small unmanned aerial vehicle (UAV) using simultaneous UAV and autopilot system design.

Abstract

Purpose

The purpose of this paper is to increase flight performance of small unmanned aerial vehicle (UAV) using simultaneous UAV and autopilot system design.

Design/methodology/approach

A small UAV is manufactured in Erciyes University, College of Aviation, Model Aircraft Laboratory. Its wing and tail is able to move forward and backward in the nose-to-tail direction in prescribed interval. Autopilot parameters and assembly position of wing and tail to fuselage are simultaneously designed to maximize flight performance using a stochastic optimization method. Results are obtained are used for simulations.

Findings

Using simultaneous UAV and autopilot system design idea, flight performance is maximized.

Research limitations/implications

Permission of Directorate General of Civil Aviation in Turkey is required for testing UAVs in long range.

Practical implications

Simultaneous design idea is very beneficial for improving UAV flight performance.

Originality/value

Creating a novel method to improve flight performance of UAV and developing an algorithm performing simultaneous design idea.

Details

Aircraft Engineering and Aerospace Technology, vol. 88 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 14 November 2012

Xia Yan, Kai Zhang, Mudassir Nawaz and Sanchit Rai

In reservoir history matching the least square objective function is usually used to minimize the mismatch between the predicted production data and the observations. However, as…

Abstract

In reservoir history matching the least square objective function is usually used to minimize the mismatch between the predicted production data and the observations. However, as history matching is an ill-posed inverse problem with non-unique solutions, the reservoir model after calibrating may be far from the real geology model by only matching the production data. In order to solve this problem, a regularization method for reservoir history matching is implemented, in which not only the production data is matched, but prior geological information is also used to correct and update the current reservoir model so that the updated model will be consistent with the geologic model. In this paper, the simultaneous perturbation stochastic approximation method (SPSA) coupled with fast streamline simulation provides an effective method (SLSPSA) to optimize the objective function. As a stochastic approximation algorithm, SLSPSA can guarantee the convergence of the algorithm. Compared to the gradient-based algorithms, it avoids the massive calculation and storage for adjoint or sensitivity matrix. In the calculation process of algorithm, parallel computing is implemented, which reduces the simulation time and improves the computational efficiency. The method was verified by matching an example test.

Article
Publication date: 8 August 2019

Xie-Fei Ding, Lin Zhan, Hui-Feng Xi and Heng Xiao

A direct and unified approach is proposed toward simultaneously simulating large strain elastic behaviors of gellan gels with different gellan polymer concentrations. The purpose…

Abstract

Purpose

A direct and unified approach is proposed toward simultaneously simulating large strain elastic behaviors of gellan gels with different gellan polymer concentrations. The purpose of this paper is to construct an elastic potential with certain parameters of direct physical meanings, based on well-designed invariants of Hencky’s logarithmic strain.

Design/methodology/approach

For each given value of the concentration, the values of the parameters incorporated may be determined in the sense of achieving accurate agreement with large strain uniaxial extension and compression data. By means of a new interpolating technique, each parameter as a function of the concentration is then obtained from a given set of parameter values for certain concentration values.

Findings

Then, the effects of gellan polymer concentrations on large strain elastic behaviors of gellan gels are studied in demonstrating how each parameter relies on the concentration. Plane-strain (simple shear) responses are also presented for gellan gels with different polymer concentrations.

Originality/value

A direct, unified approach was proposed toward achieving a simultaneous simulation of large elastic strain behaviors of gellan gels for different gellan polymer concentrations. Each parameter incorporated in the proposed elastic potential will be derived as a function of the polymer concentration in an explicit form, in the very sense of simultaneously simulating large strain data for different concentrations.

Details

Multidiscipline Modeling in Materials and Structures, vol. 15 no. 5
Type: Research Article
ISSN: 1573-6105

Keywords

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