Production of a trill depends on several articulatory and aerodynamic constraints. These constraints can be held responsible for various sound changes in Slavic languages which all involve depalatalization or frication of ProtoSlavic palatalized trilled r. As soon as a trill is affected by palatalization, the aerodynamic conditions are changed and the possibility of trill production lowers. Sma...

We investigate the use of simple aerodynamic models for the feedback control of underactuated aerial vehicles flying with large flight envelopes. Thrust-propelled vehicles with a body shape symmetric with respect to the thrust axis are considered. Upon a condition on the aerodynamic characteristics of the vehicle, we show that the equilibrium orientation can be explicitly determined as a functi...

the aim of this work is to find an efficient aerodynamic-based design algorithm for projectile fins and configuration shape optimization. three-dimensional supersonic flow over a projectile with fins at much number 5 and one degree angle of attack was studied. the runge-kutta method and multi-block technique was used to solve the governing equations. a basic configuration was assumed for the fi...

large-scaled blade has posed many problems related to design and production. After introducing the features of blade with thick airfoils and flatback, based on relevant parameters of Huaren 100 kW wind turbine, the paper designed blade with thick airfoils and flatback, introduced blade parameter design, and analyzed the aerodynamic performance of blades using GH bladed software, obtaining the r...

A significant improvement to the development of CFD-based unsteady aerodynamic reduced-order models (ROMs) is presented. This improvement involves the simultaneous excitation of the structural modes of the CFD-based unsteady aerodynamic system that enables the computation of the unsteady aerodynamic state-space model using a single CFD execution, independent of the number of structural modes. F...

This work was one of the tasks of the Manufacturing2Client project, whose objective was to develop a frontal deflector to be commercialized in the automotive industry, using new project and manufacturing methods. In this task, in particular, it was proposed to develop the ability to predict computationally the aerodynamic influence of flow in vehicles, in an effort to reduce fuel consumption in...

This paper describes a parallel genetic algorithm (GA) which is linked to aerodynamic and structural analysis for multidisciplinary optimisation of wings. The method has been applied to 2D aerodynamic section design, to the aerodynamic optimisation of wings and to combined aerodynamic and structural optimisation. The parallel genetic algorithm commences with the subdivision of the entire popula...

This paper identifies the unsteady aerodynamic forces and moments for a typical section contained in the NACA Report No. 496, “General Theory of Aerodynamic Instability and the Mechanism of Flutter,” by Theodore Theodorsen. These quantities are named Theodorsen’s aerodynamic forces (TAFs). The TAFs are compared to the generalized aerodynamic forces (GAFs) for a very high aspect ratio wing (AR =...

Adjustments to cricothyroid and thyroarytenoid muscle activation are critical to the control of fundamental frequency and aerodynamic aspects of vocal fold vibration in humans. The aerodynamic and physical effects of these muscles are not well understood and are difficult to study in vivo. Knowledge of the contributions of these two muscles is essential to understanding both normal and disorder...

During high-speed pursuit of prey, the cheetah (Acinonyx jubatus) has been observed to swing its tail while manoeuvring (e.g. turning or braking) but the effect of these complex motions is not well understood. This study demonstrates the potential of the cheetah's long, furry tail to impart torques and forces on the body as a result of aerodynamic effects, in addition to the well-known inertial...