Finite element stress analysis and topological optimization of a commercial aircraft seat structure

In recent years, the Finite Element Method (FEM) has emerged as a cornerstone in the field of seating design, particularly within the aircraft industry. Over the past decade, significant advancements in Finite Element (FE) analysis techniques have revolutionized the seat industry, enabling the creation of safer and more cost-effective seat designs. The accuracy of FE analysis plays a pivotal role in this transformation. In the process of constructing a reliable finite element model, the selection and precise manipulation of key parameters are paramount. These crucial parameters encompass element size, time scale, analysis type, and material model. Properly defining and implementing these parameters ensures that the FE model produces accurate results, closely mirroring real-world performance. Verification of Finite Element Analysis (FEA) results is commonly accomplished through experimental methods. Notably, when the parameters are appropriately integrated into the modelling process, FE analysis outcomes closely align with experimental results. This study aims to leverage the power of FEM in performing static stress analysis and topology optimization of aircraft seats using the SOLIDWORKS commercial finite element platform. By simulating loading conditions, this research calculates static stresses and displacements experienced by the aircraft seat. For AL7075-T6(SN) the structural analysis demonstrates that this material had a maximum stress of 125.2 N/mm 2 and a minimum stress of 0.0039 N/mm 2. Due to its strong 4.034 factor of safety, the component may have been over-engineered for its intended use. However, at 2.32 kg, the component's mass and $2.304/kg material cost showed a high design cost. The maximum Y-component of displacement was 0.0606 mm, which was acceptable but could have been optimized to decrease material use and expense without affecting structural integrity. After performing topology optimization on Simulation 1 of AL7075-T6(SN), several improvements have been achieved. The maximum stress sustained by the component has been elevated to 189.4 N/mm 2. However, it is worth noting that the minimum stress has also risen, although to a negligible value of 0.0006 N/mm 2. The compromise in this scenario is characterized by a fall in the factor of safety to 2.666, suggesting a design that is more optimal but possibly associated with more risk. The most notable improvements, however, concern weight reduction. The overall mass of the component saw a substantial reduction, reaching 1.89 kg, which represents a notable improvement on the original design. Through a comprehensive topology optimization study, the weight of the airplane seat is remarkably reduced by up to 30%, while still prioritizing passenger safety. The success of this optimization showcases the potential for substantial weight savings in aircraft seat design without compromising safety standards

Analysis of the concurrent validity and reliability of five common clinical goniometric devices

Measurement errors play an important role in the development of goniometric equipment, devices used to measure range of motion. Reasonable validity and reliability are critical for both the device and examiner before and after to testing in human subjects. The objective is to evaluate the concurrent validity and reliability of five different clinical goniometric devices for the purpose of establishing an acceptable measurement error margin for a novel device. We explored the validity and inter- and intrarater reliability scores of five goniometric devices namely (i) the universal goniometer (UG), a two-armed hand-held goniometer, (ii) the inclinometer (IC), featuring a single base, fluid level, and gravity-weighted inclinometer, (iii) the digital inclinometer (DI), functioning as both a DI and dynamometer, (iv) the smartphone application (SA), employing gyroscope-based technology within a smartphone platform application and (v) the modified inclinometer (MI), a gravity pendulum-based inclinometer equipped with a specialized fixing apparatus. Measurements were obtained at 12 standard angles and 8 human shoulder flexion angles ranging from 0° to 180°. Over two testing sessions, 120 standardized angle measurements and 160 shoulder angle measurements from 20 shoulders were repetitively taken by three examiners for each device. The intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC) were calculated to assess reliability and validity. Concurrent validity was also evaluated through the execution of the 95% limit of agreement (95% LOA) and Bland–Altman plots, with comparisons made to the UG. The concurrent validity for all device pairs was excellent in both study phases (ICC > 0.99, 95% LOA − 4.11° to 4.04° for standard angles, and − 10.98° to 11.36° for human joint angles). Inter- and intrarater reliability scores for standard angles were excellent across all devices (ICC > 0.98, SEM 0.59°–1.75°, MDC 1°–4°), with DI showing superior reliability. For human joint angles, device reliability ranged from moderate to excellent (ICC 0.697–0.975, SEM 1.93°–4.64°, MDC 5°–11° for inter-rater reliability; ICC 0.660–0.996, SEM 0.77°–4.06°, MDC 2°–9° for intra-rater reliability), with SA demonstrating superior reliability. Wider angle measurement however resulted in reduced device reliability. In conclusion, our study demonstrates that it is essential to assess measurement errors independently for standard and human joint angles. The DI is the preferred reference for standard angle testing, while the SA is recommended for human joint angle testing. Separate evaluations across the complete 0°–180° range offer valuable insights

SPARC 2019 Fake news & home truths : Salford postgraduate annual research conference book of abstracts

Welcome to the Book of Abstracts for the 2019 SPARC conference. This year we not only celebrate the work of our PGRs but also our first ever Doctoral School Best Supervisor awards, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 90 presenters, the conference truly showcases a vibrant, innovative and collaborative PGR community at Salford. These abstracts provide a taster of the inspiring, relevant and impactful research in progress, and provide delegates with a reference point for networking and initiating critical debate. Find an abstract that interests you, and say “Hello” to the author. Who knows what might result from your conversation? With such wide-ranging topics being showcased, we encourage you to take up this great opportunity to engage with researchers working in different subject areas from your own. To meet global challenges, high impact research needs interdisciplinary collaboration. This is recognised and rewarded by all major research funders. Engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers. Even better, our free ice cream van means that you can have those conversations while enjoying a refreshing ice lolly

Computation of rheological nanofluid coating boundary layer transport with convective wall heating

Non-Newtonian nanofluids offer significant advantages in thermal enhancement in a variety of applications including in numerous areas of engineering including solar collectors and nano-coating manufacturing processes. When combined with porous media, yet further benefits can be gained in for example flow and heat transfer manipulation in nano-rheological coating extrusion. Motivated by exploring this industrial application, to furnish a deeper understanding of the rheological and nanoscale effects of such fluids in porous media, we examine the steady two dimensional (2-D) laminar buoyancy-driven boundary layer flow of power-law nanofluids along vertically upward surface adjacent to an isotropic Darcian porous filtration medium. Buongiorno's two-component nanofluid model is deployed. Scaling group transformations followed by dimensional analysis is used to developed group invariants and hence the primitive conservation equations for momentum, heat and NVF are transformed from partial differential equations into ordinary differential equations with associated wall and free stream boundary conditions. The reduced nonlinear boundary value problem has been solved computationally with the stable, rapidly convergent Runge-Kutta-Fehlberg fourth-fifth order numerical method available in the symbolic platform, Maple 18. Verification of the methodology with earlier Blottner finite difference computations in the literature for the special case of Nc = Nd = 0 is included. It is found that the reduced Nusselt number increases with convective-conduction parameter, Nc, while it is suppressed with increasing power-law index, n, and thermophoresis parameter, Nt. The reduced Sherwood number is enhanced with Lewis number, Le and convective-diffusion parameter, Nd whereas it is substantially depleted with increasing power-law index, n. Strong boundary layer flow acceleration is induced with higher Nc values. Temperature is also strongly boosted with an elevation in power-law index and both convection-conduction Nc and convection-diffusion Nd parameters. Dilatant i. e. shear-thickening nanofluids (n > 1) are observed to achieve the best thermal enhancement. The novelty of the current work is the rigorous analysis of different rheological and wall heating and nanoparticle volume fraction effects on nano-polymer coating flows which significantly extends existing studies.

Modeling and Analysis of MHD Free Convective Thermo-Solutal Transport in Casson Fluid Flow with Radiative Heat Flux

This research paper presents a novel mathematical model aimed at exploring practical applications in oscillating MHD generators and near-wall flows using Casson fluid. The purpose of this study is to develop a mathematical model that specifically addresses MHD free convective thermo-solutal transport within Casson fluid flow over a rotating vertical wall into a permeable medium. This research also considers factors like the Soret effect, radiative heat flux, first-order chemical reactions, and heat source/sink effects. To tackle this complex scenario, we apply the Laplace transform technique (LTT) to handle the transformed partial differential equations and their accompanying boundary conditions. The study investigated both ramped and isothermal wall temperature conditions and evaluated the influence of various parameters, including the Soret number, Hall current parameter, ramped wall temperature, and magnetic body force parameter. The computational analysis is carried out using MATLAB software. The research involves a comprehensive parametric analysis that thoroughly examines the impact of key emerging parameters on generalized velocity, temperature, and species concentration. The results reveal that magnetic, Casson, and rotating parameters all have a diminishing impact on the velocity profiles. The radiation parameter has a positive impact on temperature distribution, while an opposite trend is observed for the Prandtl number. Furthermore, an increase in the Soret number and chemical reaction parameter leads to a decrease in species concentration and solutal boundary layer thickness. The validation process includes comparisons with previous studies. Additionally, this study presents distributions of skin friction, Nusselt number, and Sherwood number. Notably, our findings 1 reveal that a ramped wall temperature results in lower velocity magnitudes compared to the isothermal wall case

Numerical simulation of natural convection in a rectangular enclosure filled with porous medium saturated with magnetic nanofluid using Buongiorno’s two-component model

Motivated by studying emerging nanofluid-based magnetic fuel cells and hybrid direct absorber solar collectors, a numerical study is presented for buoyancy-driven flow in a vertical enclosure containing a porous medium saturated with magnetised nanofluid flow under a transverse static magnetic field. The enclosure features adiabatic side walls and vertical heat slits, ensuring consistent cold temperatures on the lower and upper bounded walls. The side walls of the regime are insulated, and the hot slits are centrally located on these walls. The finite difference method (FDM) is applied to employ the transformed dimensionless vorticity-stream function (VSF) formulation of the transport equations. The impact of pertinent parameters on isotherm, streamline, iso-concentration, average Nusselt and Sherwood numbers are visualized with contour plots and graphs. Increasing Darcy number values tend to amplify the isotherm magnitudes. Higher Hartmann (magnetic) number values, on the other hand, lead to a reduction in local Nusselt number profiles but do not significantly modify the local Sherwood number. The porous medium permeability, as simulated via the Darcy number, has a strong impact on streamlines, thermal contours, and iso-concentrations. A reduction in Darcy's number suppresses local Nusselt and Sherwood numbers, whereas an elevation in 2 Rayleigh's number enhances them. Increasing the Buongiorno nanoscale Brownian motion parameter enhances local Nusselt and Sherwood numbers at both cold walls of the enclosure. The simulations provide a deeper insight into enclosure flows involving electrically conducting nanofluids in advanced processing systems for nanomaterials and hybrid fuel cells utilizing electromagnetic and liquid fuel technologies

Analysis of the concurrent validity and reliability of five common clinical goniometric devices

Abstract Measurement errors play an important role in the development of goniometric equipment, devices used to measure range of motion. Reasonable validity and reliability are critical for both the device and examiner before and after to testing in human subjects. The objective is to evaluate the concurrent validity and reliability of five different clinical goniometric devices for the purpose of establishing an acceptable measurement error margin for a novel device. We explored the validity and inter- and intrarater reliability scores of five goniometric devices namely (i) the universal goniometer (UG), a two-armed hand-held goniometer, (ii) the inclinometer (IC), featuring a single base, fluid level, and gravity-weighted inclinometer, (iii) the digital inclinometer (DI), functioning as both a DI and dynamometer, (iv) the smartphone application (SA), employing gyroscope-based technology within a smartphone platform application and (v) the modified inclinometer (MI), a gravity pendulum-based inclinometer equipped with a specialized fixing apparatus. Measurements were obtained at 12 standard angles and 8 human shoulder flexion angles ranging from 0° to 180°. Over two testing sessions, 120 standardized angle measurements and 160 shoulder angle measurements from 20 shoulders were repetitively taken by three examiners for each device. The intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC) were calculated to assess reliability and validity. Concurrent validity was also evaluated through the execution of the 95% limit of agreement (95% LOA) and Bland–Altman plots, with comparisons made to the UG. The concurrent validity for all device pairs was excellent in both study phases (ICC > 0.99, 95% LOA − 4.11° to 4.04° for standard angles, and − 10.98° to 11.36° for human joint angles). Inter- and intrarater reliability scores for standard angles were excellent across all devices (ICC > 0.98, SEM 0.59°–1.75°, MDC 1°–4°), with DI showing superior reliability. For human joint angles, device reliability ranged from moderate to excellent (ICC 0.697–0.975, SEM 1.93°–4.64°, MDC 5°–11° for inter-rater reliability; ICC 0.660–0.996, SEM 0.77°–4.06°, MDC 2°–9° for intra-rater reliability), with SA demonstrating superior reliability. Wider angle measurement however resulted in reduced device reliability. In conclusion, our study demonstrates that it is essential to assess measurement errors independently for standard and human joint angles. The DI is the preferred reference for standard angle testing, while the SA is recommended for human joint angle testing. Separate evaluations across the complete 0°–180° range offer valuable insights