CFD Simulation of Air Flow Behaviour at Different Flow Rates in a Turkish Woodwind Instrument (Turkish Treble Recorder)

In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-based handcrafting methods are predominant in the production of Turkish Folk Music wind instruments. The instrument manufacturing and standardization approaches, which include the relevant rules of physics and engineering practices, are limited purely to prototype studies for scientific research purposes. It is almost impossible to find studies on Turkish Folk Music wind instrument design and production involving computer aided design and engineering applications. In this study, an example Turkish woodwind instrument, the Turkish Treble Recorder (dilli kaval) is considered, and the air flow behaviour and acoustic (sound) power magnitudes that occur at different air flow rates are simulated in a computer environment using a Computational Fluid Dynamics (CFD) simulation technique. In the study, numerical and visual outputs related to air behaviour at different air flow rates that may be used in the instrument manufacturing phases were obtained. Acoustic power level was also measured experimentally. Simulation outputs (the acoustic power level) were compared to experimental results in order to validate the simulation results. The comparison revealed that the highest relative difference was calculated as 13.32(%). This value indicated that the simulation results were reasonably consistent with the results of the experimental measurement. Additionally, this study was constructed as a case study that may provide reference for future research studies in this field

A Numerical Method-Based Analysis of the Structural Deformation Behaviour of a Turkish String Instrument (Cura Baglama) under Varying String Tensions

This study focuses on the structural design analysis of a cura baglama, a traditional Turkish string instrument that does not have in place a regulated set of manufacturing standards to follow. The aim therefore is to introduce a structural deformation analysis for a sample cura baglama in three different string tensions via a numerical method-based engineering analysis technique. The three-dimensional solid model of a sample cura baglama was created using a 3D scanner and parametric 3D solid modelling software. Based on experimental frequency analysis, structural deformation analyses of the instrument were conducted using finite element method-based engineering simulation techniques. The simulation results revealed useful visual and numerical outputs related to the deformation behaviour of the instrument under pre-defined boundary conditions. A maximum deformation of 0.223 mm on the soundboard (at the D3 tune) and a maximum equivalent stress of 18.325 MPa on the bridge (at the D3 tune) were calculated. The outputs of this research contribute to further research into the usage of numerical method-based deformation simulation studies related to the standardisation, development, and preservation of such traditional string instruments

The effects of bud load and regulated deficit irrigation on sugar, organic acid, phenolic compounds and antioxidant activity of Razaki table grape berries

38th World Congress of Vine and Wine -- JUL 05-10, 2015 -- Mainz, GERMANYWOS: 000359945200002This study aims at assessing the effects of increased bud load and irrigation applications on berry quality of the Razaki table grape. Two Regulated Deficit Irrigation (RDI) having different irrigation levels (RDI-I and RDI-II) based on the growth stages, in addition to a non-irrigated control treatment together with two different bud load practices (K-normal and 2K-two-fold buds of the normal) were examined for their effects on quality attributes such as sugar and organic acids contents, phenolic compounds as well as antioxidant capacity of the berries. The non-irrigated vines had highest sugar level (198.86 g/kg) in the first year (2013) of the experiment whilst the sugar content of the berries was increased with irrigation (RDI-II) in 2014. However the highest organic acid (7.10 g/kg) was recorded from the RDI-II treatment in 2013 whereas those of from non-irrigated vines were highest (7.81 g/kg) in 2014. Considering the sugar and organic acid content of the berries, bud load effects were not significant. The total phenolic acids were higher under non-irrigated and 2K bud load conditions. Antioxidant activity of berries was increased with RDI-I irrigation and 2K practices in the first year (2013) although no significant effect was recorded in the second year of the experiment. In all applications, glucose among the sugars, tartaric acid among the organic acids, catechin and epicatechin among the phenolic compounds were detected to be higher compared to other components in berries