Challenges and difficulties for a Vice-principal for research

In the onset of our journey as a governing team, many feelings and ideas intermingle. In my case, as the new Vice-Principal for Research of the University of Valencia, I enthusiastically take on the responsibility of coordinating and facilitating the work of the researchers of the University of Valencia. Evidently, many challenges exist and resources are limited, but in recent years we have also managed to maintain and even increase research activity in science and humanities

Consideraciones Acerca del Bombardero en Medio de Densidad Variable

Continuamente se presentan nuevos problemas en la realización y estudio de un bombardeo, al irse incrementando día por día la altura de lanzamiento. Es preciso tener en cuenta todos los factores que intervienen en el problema, factores que en estudios anteriores se despreciaban por no tener influencia sensible en los resultados numéricos obtenidos. Uno de los factores que han adquirido importancia con dicho incremento de altura es la densidad atmosférica

Analytic model of a cache-only memory architecture

An approximate analytic model of a shared memory multiprocessor with a Cache Only Memory Architecture (COMA), the busbased Data Difussion Machine (DDM), is presented and validated. It describes the timing and interference in the system as a function of the hardware, the protocols, the topology and the workload. Model results have been compared to results from an independent simulator. The comparison shows good model accuracy specially for non-saturated systems, where the errors in response times and device utilizations are independent of the number of processors and remain below 10% in 90% of the simulations. Therefore, the model can be used as an average performance prediction tool that avoids expensive simulations in the design of systems with many processors

Nonlinear evolution of harmonically forced perturbations on a wingtip vortex

Wingtip vortices are created by flying airplanes due to lift generation. The vortex interaction with the trailing aircraft has sparked researchers’ interest to develop an efficient technique to destroy these vortices. Different models have been used to describe the vortex dynamics and they all show that, under real flight conditions, the most unstable modes produce a very weak amplification. Another linear instability mechanism that can produce high energy gains in short times is due to the non-normality of the system. Recently, it has been shown that these non-normal perturbations also produce this energy growth when they are excited with harmonic forcing functions. In this study, we analyze numerically the nonlinear evolution of a spatially, pointwise and temporally forced perturbation, generated by a synthetic jet at a given radial distance from the vortex core. This type of perturbation is able to produce high energy gains in the perturbed base flow (10^3), and is also a suitable candidate for use in engineering applications. The flow field is solved for using fully nonlinear three-dimensional direct numerical simulation with a spectral multidomain penalty method model. Our novel results show that the nonlinear effects are able to produce locally small bursts of instability that reduce the intensity of the primary vortex.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Effect of the axial jet on the optimal response in Batchelor vortex

En este póster se estudia la respuesta óptima del torbellino de Batchelor para distintos números de onda. Se demuestra que incluso teniendo la velocidad axial, un torbellino es capaz de tener grandes amplificaciones de energía.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Wingtip vortex in a NACA0012 airfoil and its active control

Contribución mediante sesión pósterWe conduct experiments in a towing-tank to analyse the flow patterns of wingtip vortices in a NACA 0012 airfoil. In this experimental research, we provide PIV measurements and flow visualisations. Without active control, several parameters are given experimentally as function of the Reynolds number, so we compare these data with the theoretical models of Batchelor, and Moore and Saffman together with DNS. Secondly, we analyse the effect of a continuous injection in the spanwise direction. The continuous jet has a strong influence on the wing-tip vortex formation. We explore this effect at low chord based Reynolds number ranging from 7000 up to 20000. We change the aspect ratio of the injection, R, defined as the ratio of the velocities between the jet (Uj) and free-stream (U). For R=1, we find that the jet strongly affects the wingtip vortex formation with a sudden decrement of the axial vorticity and the azimuthal velocity. This technique is a challenge and a promising tool to reduce the intensity of the vortex core.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

On the effect of low blowing ratio continuous jets on wingtip vortex characteristics

Vortices are an unavoidable effect of flight, which appear behind the wing with a bounded length. The strength of these vortices, which are extremely stable, is due to the lift force [1]. That is the reason why this phenomenon is especially relevant during take-off and landing operations. In these situations, when aircraft are departing from or arriving to the airport runways, the following aircraft might feel two counter-rotating vortices which remain long time under normal environmental conditions. Unfortunately, this huge rotation of airflow patterns always destabilizes the following aircraft. Consequently, trailing vortices have a mighty influence on the air traffic control of airport runways, and they have justified the research interest in this topic since the 1960's [2]. However, aeronautical engineers are still searching for different technological strategies to breakdown these wingtip vortices.Short-Term Postdoctoral Stay of Talent Attraction Plan of Andalucía TECH ICE. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Mechanisms underlying the influence of oestrogen on cardiovascular physiology in women

Women show a lower incidence of cardiovascular diseases than aged-matched men, but this benefit disappears after menopause. Oestrogen-mediated vascular actions are mainly attributed to oestradiol and exerted by oestrogen receptors (ERα, ERβ, and GPER), through rapid and/or genomic mechanisms, but these effects depend on ageing and inflammation. A cardiovascular approach in women's health has arisen due to controversy regarding oestrogens' beneficial impact as reported in experimental and observational studies and large randomized trials. These can be explained, in part, by two mutually non-exclusive hypotheses. On the one hand, the timing hypothesis, which states that oestrogen-mediated benefits occur before the detrimental effects of ageing are established in the vasculature; on the other hand, ageing and/or hormonal-associated changes in ER expression that could lead to a deleterious imbalance in favour of ERβ over ERα, generally associated with higher inflammation and endothelial dysfunction. In experimental studies, oestradiol acting on ERα promotes the release of vasoactive compounds such as nitric oxide (NO) and prostacyclin, and shifts the angiotensin axis towards angiotensin 1-7 production. Mechanisms underlying oestradiol vascular function also include anti-inflammatory and epigenetic modifications. 17β-oestradiol changes the transcriptomic profile of endothelial cells, and the involvement of miRNA in the regulatory pathways of vascular function reinforces assumptions regarding the vascular actions of oestrogen. Thus, the present symposium review aims to postulate the role of ERα in oestrogen modulation of endothelial-derived mediators and vascular physiology, as well as its relationship with miRNA and inflammation, and elucidate how physiological changes in postmenopausal women counteract the observed effects