OBJECTIVES To use computational fluid dynamics (CFD) for evaluating and understanding the performance of the high-dose disposable Twincer™ dry powder inhaler, as well as to learn the effect of design modifications on dose entrainment, powder dispersion and retention behaviour. METHODS Comparison of predicted flow and particle behaviour from CFD computations with experimental data obtained wit...

Considerable progress in development and application of computational fluid dynamics (CFD) for aeroengine internal flow systems has been made in recent years. CFD is regularly used in industry for assessment of air systems, and the performance of CFD for basic axisymmetric rotor/rotor and stator/rotor disc cavities with radial throughflow is largely understood and documented. Incorporation of t...

This paper describes and analyzes a series of nearly CFD test cases performed as a contribu tion to the second Drag Prediction Workshop held in association with the AIAA in June Two con gurations are included DLR F wing body and wing body nacelle pylon The ability of CFD to pre dict the drag lift and pitching moment from exper iment including the delta arising from the ad dition of the nacelle ...

Objective The objective was to study the performance of an in-house developed wall shear stress (WSS) algorithm using PC-MRI in intracranial aneurysms. Materials & Methods First, the algorithm was applied to a high resolution in vitro PC-MRI measurement under steady and pulsatile fl ow conditions. A CFD simulation was performed with similar infl ow boundary conditions. Second, WSS was estimated...

conclusion both techniques provided quantitatively consistent results of in vivo velocity vector fields in right internal carotid artery (rca). pc mri represented a good estimation of main flow patterns inside the vasculature, which seems to be acceptable for clinical use. however, limitations of each technique should be considered while interpreting results. subjects and methods mr imaging was...

This study introduced a combined computational fluid dynamics (CFD) and echocardiography methodology to simulate blood flow in the single right ventricle (SRV) and normal ventricles to study the intraventricular flow. Derived from echocardiographic image loops, CFD-based three-dimensional (3D) flow models of normal subject's left ventricle (LV) and right ventricle (RV) and SRV with and without ...

A local proper orthogonal decomposition (POD) plus Galerkin projection method is applied to the unsteady lid-driven cavity problem, namely the incompressible fluid flow in a twodimensional box whose upper wall is moved back and forth at moderately large values of the Reynolds number. Such a method was recently developed for one-dimensional parabolic problems. Its extension to fluid dynamics pro...

Reynolds-Averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) analysis was conducted to study the low-speed stall aerodynamics of a GIII aircraft’s swept wing modified with a laminar-flow wing glove. The stall aerodynamics of the gloved wing were analyzed and compared with the unmodified wing for the flight speed of 120 knots and altitude of 2300 ft above mean sea level (MSL). The S...

Background and purpose: Delayed cerebral ischemia (DCI) is a significant cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (SAH). Recently, we reported the various hemodynamic characteristics of ruptured aneurysm with computational fluid dynamics (CFD). The aim of this study was to assess whether CFD was useful to predict the development of DCI after SAH. Materials and m...

Evaluation of Various Turbulence Models in Predicting Airflow and 1 Turbulence in Enclosed Environments by CFD: Part-1: 2 Summary of Prevalent Turbulence Models 3 4 Zhiqiang Zhai Zhao Zhang Wei Zhang Qingyan Chen 5 Member ASHRAE Student Member ASHRAE Member ASHRAE Fellow ASHRAE 6 7 Air distributions in enclosed environments are crucial to thermal comfort and air quality. 8 Computational fluid d...