A CFD Analysis for Novel Close-Ended Deflector for Vertical Water Turbines

Mohammed Baqer Zaki Yahya Al-Quraishi,Shamsul Sarip,Hazilah Mad Kaidi,Jorge Alfredo Ardila-Rey,Firdaus Muhammad-Sukki

doi:10.3390/su14052790

Abstract

The effects of climate change are growing more and more evident, and this is caused by the increase in CO2 emissions. Fossil fuel exhaustion and the need for electricity in remote areas have encouraged researchers to advance and develop the renewable energy sector. One type of clean energy technology is vertical water turbines that have low efficiency. This paper aims to design and simulate a novel close-ended, guided deflector to improve the efficiency of vertical turbines. This research used the dynamic mesh technique to evaluate the concept after the deflector was designed, and a grid independence study, a boundary sensitivity study, and a timestep sensitivity study were implemented to ensure the accuracy of the results. Then, we used the sliding mesh model to determine the performance of four rotors. The results from the dynamic mesh model showed that the straight rotor with the proposed deflector was not suitable for operating in the deflector, and the concept is static and does not rotate. However, the others showed a valid concept in the proposed deflector. For the sliding mesh technique, the results indicated a common trend: all the rotors’ performances increased when tip speed ratio (TSR) increased, and the highest amount of the power coefficient (Cp) was found at higher TSRs, such as 1.3 and 1.4, with around 0.45 in the cross flow type. A three-dimensional simulation was conducted of the cross flow type with the proposed deflector, and a similar trend was found. Nevertheless, around a 5% difference was found between the 3D and 2D results for cross flow. The deflector can significantly improve the performance after 0.7 TSR to reach over 0.42 Cp at 1.3 TSR, whereas, without the deflector, the performance reduces to approximately 0.1 Cp at the same TSR.

Highlights

Introduction iationsSocial and economic growth is strongly related to improvements in the energy sector [1]
The authors investigated three different deflector types, and the results found that the peak value of performance with the deflector in use was increased by 17.47%
9, the firstissimulation wastwo for parts, the deflector itself, and it can be be seen that the core of the deflector divided into low- and high-velocity seen thatThat the core ofsame the deflector is divided into designing two parts, the low-deflector, and high-velocity regions

Summary

Introduction

Introduction iationsSocial and economic growth is strongly related to improvements in the energy sector [1]. The primary way to produce electricity is by burning fossil fuels because their cost is relatively reasonable, and they can be exploited . Using environmentally friendly energy sources is an effective technique for mitigating fossil fuel exploitation and carbon emissions [4,5]. Small-scale hydropower turbines can help to provide electricity to rural areas in developing countries since 10% of the global population lived without electricity according to 2019 data [6]. Many areas in Malaysia, especially East Malaysia, suffer from a lack of electricity due to their distant location from cities [7]. These rural areas depend on fossil fuel generators.

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