Noise Generation and Acoustic Impact of Free Surface Hydropower Machines: Focus on Water Wheels and Emerging Challenges.

Emanuele Quaranta,Gerald Müller

doi:10.3390/ijerph182413051

Abstract

The noise generated by free surface hydropower machines, e.g., water wheels, has led to complaints and to restrictions in their operation in urban areas. This problem generally occurs when water wheels are not well designed and are installed without expertise. Despite the relevance of the problem, and the growing interest in the use of water wheels at existing low head barriers, the acoustic impact of water wheels has not yet been properly addressed by the scientific community. Therefore, in this manuscript, the importance of the problem and the related scientific challenges are discussed, supported by case studies and theoretical considerations. A literature review on the topic is carried out, although little information is available in the scientific domain. The aim of this work is to increase the awareness on this problem, in order to stimulate future research and to suggest useful guidelines for future water wheel projects, thereby increasing the water wheel potential and reducing noise disturbance for people.

Highlights

IntroductionGravity hydraulic machines use water weight to generate energy. The two most known types of gravity machines are gravity water wheels, used in the past to drive water mills [1], and Archimedes screws [2]
Gravity water wheels are the focus of this study
A collection of case studies and related scientific studies show that the problem of noise generation by water wheels should not be overlooked

Summary

Introduction

Gravity hydraulic machines use water weight to generate energy. The two most known types of gravity machines are gravity water wheels, used in the past to drive water mills [1], and Archimedes screws [2]. 1000 L/s per meter width, with a maximum hydraulic efficiency of 80% and global plant efficiency of 65% [7], depending on the head and flow rate; the inflow is located in the lowest portion of the wheel (Figure 1a). They can be of two main types: Sagebien type with flat blades and Zuppinger type with curved blades [7]. L/sand per publications meter width, with a maximum hydraulic of 85% and available data on the noise generated byefficiency water wheels. The only available review paper deals with the noise generated by hydraulic weirs for low head applications [12]. The scope of the present opinion paper is to discuss the available data and publications on the noise generated by water wheels.

Noise Generation from Water Wheels

Assessment of Noise Emissions from Water Wheels

Outlook and Challenges

Findings

Conclusions