In this paper, the design and validation of a heat storage device based on phase change materials are presented, with focus improving thermal control micro-satellites. The main objective development is to provide system that able keep electronics within safe temperature ranges during operation manoeuvres, while reducing mass volume in comparison other techniques. Due low conductivity materials, as whole one major challenges development. This issue has been solved by means use lattice...

Diamond like carbon (DLC) coatings typically present good self-lubricating tribological properties that could be of interest in sliding dielectric contacts multiple electrical applications. In this work electro-tribological studies have been performed on several DLC against aluminum different humidity conditions, which the coefficients friction (CoFs) and contact resistance (ECR) were continuously monitored. Results show CoF ECR data can linked to (thickness, finishing, microstructure,...

The correlation of the thermal mathematical models (TMMs) spacecrafts with results test is a demanding task in terms time and effort. Theoretically, it can be automatized by means optimization techniques, although this challenging task. Previous studies have shown ability genetic algorithms to perform several cases, some limitations been detected. In addition, gradient-based methods, also presenting limitations, provided good solutions other technical fields. For reason, performance methods...

Due to their high propulsive efficiency, counter-rotating open rotors (CRORs) have the potential significantly reduce fuel consumption and emissions relative conventional bypass ratio turbofans. However, this novel engine architecture presents many design operational challenges both at aircraft level. The assessment of impact main low-pressure preliminary control parameters CRORs on mission burn, certification noise, is necessary stages in order identify optimum regions. These assessments...

Due to their high propulsive efficiency, counter-rotating open rotors (CRORs) have the potential significantly reduce fuel consumption and emissions relative conventional bypass ratio turbofans. However, this novel engine architecture presents many design operational challenges both at aircraft level. The assessment of impact main low-pressure preliminary control parameters CRORs on mission burn, certification noise, is necessary stages in order identify optimum regions. These assessments...

Typically, segregated methods have been used for the computation of incompressible flows whereas coupled solvers, compressible flows. Compared to present advantage computational savings in RAM memory and CPU time, although at cost an inferior robustness. However, previously published algorithms general are known pitfalls, like convergence wrong solutions, lack robustness presence strong discontinuities, such as normal oblique shocks, complicated boundary condition imposition. Therefore, this...

Composite moulds constitute an attractive alternative to classical metallic when used for components fabricated by processes such as Resin Transfer Moulding (RTM). However, there are many factors that have be accounted if a correct design of the is sought after. In this paper, Finite Element Method (FEM) help in mould. To do so, thermo-electrical simulation has been performed through MSC-Marc preheating phase order ensure mould able heated, Joule’s effect, according thermal cycle specified...

There are always differences between the computer predicted temperatures of a spacecraft thermal model and measured during mandatory laboratory tests. As consequence, must be correlated before is launched to space, in order identify correct parameters that match experimentally temperatures. A new technique presented parameters, based on minimization error transient equations which governs heat transfer spacecraft. The steady state was previous work, but techniques hereafter enable better...

Abstract Traditionally, coupled methods have been employed for the computation of compressible flows, whereas segregated preferred incompressible flows. Compared to methods, solvers present advantage reduced computer memory and CPU time requirements, although at cost an inferior robustness. Therefore, in a series papers we unified computational techniques compute flows with stabilized methods. The proposed algorithms increased robustness compared existing techniques, while possessing...

Among the different options for solid lubrication, MoS2 is probably most attractive due to its extremely low friction levels. Recent developments in magnetron sputtering physical vapour deposition (PVD) technology have allowed development of composite thin films with more compact structures, behaviour and enhanced wear resistance, reducing degradation by humidity. The present work provides an overview recent dry lubrication deposited modern PVD how these alloyed Ti or WC can outperform...

The use of optimization algorithms to adjust the numerical models with experimental values has been applied in other fields, but efforts done metal casting sector are much more limited. advances this area may contribute get adjusted less time improving confidence their predictions and contributing reduce tests at laboratory scale. This work compares performance four (compass search, NEWUOA, genetic algorithm (GA) particle swarm (PSO)) adjustment simulation models. case study used comparison...

In this 2-part publication, the impact of main low pressure system parameters a counter rotating Geared Open Rotor (GOR) on mission fuel burn, certification noise and emissions is presented for 160 PAX medium haul class aircraft. Due to their high propulsive efficiency, GORs have potential significantly reduce consumption relative conventional bypass ratio turbofans. However, novel engine architecture presents many design operational challenges both at aircraft level. The assessment...

Bonded composite patches are very appropriate for aircraft structural repair, showing good properties when compared with traditional mechanical fastening of metal sheets. The curing process the patch must be done “onsite” and a direct resistive heating method has been proposed. heat produced by electric current through Joule effect crossing carbon fibre bundles modelled Finite Element Program code, developed equation. conduction equation also in program, as well kinetics reaction resin....