WIND RESOURCES IN THE URBAN STRUCTURE – CFD NUMERICAL ANALYSIS. POSSIBILITIES OF USING WIND ENERGY ONTHE EXAMPLE OF THE SŁONECZNE ESTATE IN SZCZECIN

The issue of wind in an urbanized structure, considered in the context of benefits, forces to undertake activities across multiple disciplines. The lack of understanding of the aerodynamic phenomena in heterogeneous space may lead to failures in implemented projects. The article presents the general scope of issues related to the urban wind turbine and the numerical CFD simulation of air flows in the Słoneczne housing estate in Szczecin, together with the conclusions drawn from it.

Numerical Analysis of Tube Heat Exchanger with Perforated Star-Shaped Fins

This article discusses the possibility of further reducing the mass of the heat exchanger with stainless steel star-shaped fins while achieving good heat transfer performance. For this purpose, we perforated the fins with holes Ø2, Ø3, and Ø4 mm. Applying computational fluid dynamics (CFD) numerical analysis, we determined the influence of each perforation on the characteristics of the flow field in the liquid–gas type of heat exchanger and the heat transfer for the range of Re numbers from 2300 to 16,000. With a reduction in the mass of the fins to 17.65% (by Ø4 mm), perforated fins had greater heat transfer from 5.5% to 11.3% than fins without perforation. A comparison of perforated star-shaped fins with annular fins was also performed. Perforated fins had 51.8% less mass than annular fins, with an increase in heat transfer up to 26.5% in terms of Nusselt number.

Influence of channel height on mixing efficiency and synthesis of iron oxide nanoparticles using droplet-based microfluidics

Experimental and CFD numerical analysis of mixing efficiency in droplet-based microfluidics for various channel heights and its impact on the preparation of iron oxide nanoparticles.

Numerical Simulation and Analysis of the Arrangement of Wind Direction Meter for Wind Turbine

This paper performs CFD numerical analysis on the wind direction variation characteristics of the upper part of the platform under the running condition of the whole machine, and analyses whether the current location of the equipment is suitable for placing the wind direction measuring equipment and finding a better position in the area. The vicinity of the reference point is the area where the airflow is relatively intense, and the wind direction is complex and changeable. In-depth CFD research on this flow phenomenon can obtain an intuitive wind direction state and inherently subtle changes.

CFD NUMERICAL ANALYSIS OF A PROPOSED CHANGE IN THE CHANNEL GEOMETRY DOWNSTREAM OF A REVERSED TAINTER GATE

Reversed Tainter gates are often used to control flow in the filling and emptying locks navigation systems of high fall. High speeds and pressure fluctuations may occur in the flow downstream of these gates, the flow cavitation may occur, damaging the structure. One way proposed to mitigate this problem is through geometric changes in the channel downstream of the gate. In this study was analyzed using CFD the effect of an expansion in the roof and the base of the conduit, followed by a straight section and a subsequent contraction until returning to the original geometry. It was observed that the pressure at the base of the conduit increases with the modification, however peaks of positive and negative pressures occur due to the shape change of the geometry of the corners not be smooth. The size of recirculation downstream of the gate increases with the geometrical alteration, increasing the distance required for pressure recovery.

CFD-Based Visualization Research on the Rotation of Hydraulic Slide Valve Spool

The hydraulic slide valve with round orifice spool is often used in hydraulic control system. But it is prone to rotate when the hydraulic oil flow is large. The three-dimensional fluid analysis technology was used to numerically simulate the flow field in the hydraulic slide valve. By using the pressure and velocity characteristics generated for different spool structures by the CFD numerical analysis, the main reason of slide valve rotation was analyzed, which can provide basis for the optimal design of the slide valve structure.

Research on Francis Turbine Hydraulic Vibration by CFD

The normal operation of the hydropower station is seriously affected by the vibration problems. This paper is about how to analysis and improve the hydraulic vibration problem by an example of a low head Francis turbine in the southwest of China with higher head. The models was built by using UG and analysed by CFD numerical analysis software to simulate the vibration conditions with air-water two-phase flow. With the reason was found by the the result of numerical calcuate, air compensation method was put out to improve the vibration condition and the optimal volume of the compensative air was calcuated to verify the solution method.