Aeroacoustic Characteristics of a Strut-braced High-lift Device

The aerodynamic and aeroacoustic performance of a strut-based high-lift device were 5 evaluated and demonstrated for six different strut models. The primary objective of the study 6 was to investigate the impact of strut modifications on reducing noise levels. The aerodynamic 7 characteristics are presented with the aid of surface pressure distribution on the airfoil that 8 remained consistent across all the tested configurations. The aeroacoustic results are presented 9 as the near-field surface pressure fluctuations and far-field noise measurements to attain a 10 profound comprehension of the noise generation mechanism. Although the Albatros strut 11 exhibited the greatest reduction in tonal noise, the directivity pattern and the overall sound 12 pressure level of the radiated noise demonstrated that the medium height strut configuration can 13 achieve noise reduction of up to 8 dB. The near-field unsteady surface pressure measurements 14 are suggestive of harmonic oscillations. The coherence studies carried out have shown a 15 decrease in the tonal coherence for the small height strut configuration while the velocity field 16 measurements performed in the wake of the high-lift device show no significant variation in 17 flow patterns between different strut configurations

A mathematical model for fibro-proliferative wound healing disorders

The normal process of dermal wound healing fails in some cases, due to fibro-proliferative disorders such as keloid and hypertrophic scars. These types of abnormal healing may be regarded as pathologically excessive responses to wounding in terms of fibroblastic cell profiles and their inflammatory growth-factor mediators. Biologically, these conditions are poorly understood and current medical treatments are thus unreliable. In this paper, the authors apply an existing deterministic mathematical model for fibroplasia and wound contraction in adult mammalian dermis (Olsenet al., J. theor. Biol. 177, 113–128, 1995) to investigate key clinical problems concerning these healing disorders. A caricature model is proposed which retains the fundamental cellular and chemical components of the full model, in order to analyse the spatiotemporal dynamics of the initiation, progression, cessation and regression of fibro-contractive diseases in relation to normal healing. This model accounts for fibroblastic cell migration, proliferation and death and growth-factor diffusion, production by cells and tissue removal/decay. Explicit results are obtained in terms of the model processes and parameters. The rate of cellular production of the chemical is shown to be critical to the development of a stable pathological state. Further, cessation and/or regression of the disease depend on appropriate spatiotemporally varying forms for this production rate, which can be understood in terms of the bistability of the normal dermal and pathological steady states—a central property of the model, which is evident from stability and bifurcation analyses. The work predicts novel, biologically realistic and testable pathogenic and control mechanisms, the understanding of which will lead toward more effective strategies for clinical therapy of fibro-proliferative disorders