This paper aims to present the study of flow through a vertical axis wind turbine of Savonius type. The studied turbine is intended to be used within a compact package with multisource of energy. The rotor has height, which is approximately equivalent to the rotor diameter. In this condition, the simulation of flow through the wind turbine needs 3D model. Due to its principle of operation and the continuous variation of flow angle with respect to blades, strong unsteady effects including separation and vortex shedding are observed. In these conditions, the turbulence modeling by means of k-ω and DES permits to obtain good results comparatively to experiments. In this work we are using CFD to study the behaviour of a Savonius wind turbine under flow field conditions and to determine its performance and the evolution of wake geometry. The flow analysis helps to qualify the design of the wind turbine. To validate simulations, experimental investigation in wind tunnel is carried out using PIV. The investigation permits to determine the structure of the real flow and to access the quality of numerical simulation

The unsteadiness of rotor inflow caused by the atmosphere creates continuous variations of blade loads and rotor torque. Usually these loads are amplified by rotor shaft and gearbox elasticity and inertia. The authors propose here a dynamic multi-body model where the wind turbine includes a rotor, a drive train and an electrical generator. The drive train has a three stage gearbox which contains two high-speed parallel gear stages and a low-speed planetary gear stage. The model consists of 10 bodies and has 8 degrees of freedom taking into account the stiffness of the engaged tooth pairs. In this model the aerodynamic torque is applied as an external load. The calculation permits to obtain natural frequencies, mode shapes, time series of torsional oscillations and amplitude-frequency characteristics for an industrial wind turbine. The results show that transient loads in the gearbox are very high and need special attention.

This paper presents the aerodynamic study of a small car, which participated in Shell Ecomarathon Europe competition in the Urban Concept Hydrogen class. The goal is to understand the flow field around the vehicle. First, the flow is studied numerically using computational aerodynamics. The numerical simulation is carried out by means of CFD Fluent in order to obtain the drag force experienced by the vehicle and also the flow field. Then the flow field around the car is studied in a wind tunnel by means of particle image velocimetry (PIV). The comparison of the flow fields obtained numerically and experimentally shows good correspondence. The obtained results are very helpful for future car development and permit to improve the drag and to obtain a good stability.

Cross-Flow Fans (CFFs) have been widely applied in the automotive and domestic air conditioning industries in recent decades. They are high-pressure coefficient turbomachines compacted diametrically, and thus, the complex interactions of these fans require thorough evaluation. Their innovation has opened up new directions in turbomachinery, and both academic research and industry have seen numerous efforts to develop these types of fans. Despite extensive work, optimizing and improving their performance remains a challenge. Enhancing their efficiency necessitates improvements in structural characteristics, aerodynamic features, and acoustic properties. In this review, we aim to demonstrate the essential aspects of CFFs by introducing their fundamentals and primary characteristics. Furthermore, we delve into a discussion on the acoustic performance of these fans. We also summarize the flow characteristics and different flow-field patterns in CFFs and their impact on aeroacoustic behavior. The main objective of this review paper is to provide an overview of the research in this field, summarizing the critical factors that play a significant role in studying CFFs’ performance.