Quantification and analysis methods aimed at the reduction of flow induced noise in the expansion device

Santambrogio, Andrea

Permalink

https://hdl.handle.net/2142/97633 Copy

Description

Title

Quantification and analysis methods aimed at the reduction of flow induced noise in the expansion device

Author(s)

Santambrogio, Andrea

Issue Date

2017-04-27

Director of Research (if dissertation) or Advisor (if thesis)

Elbel, Stefan

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Expansion valve
• Noise

Abstract

A cultural context where acoustic technologies are rapidly growing, and the demand for comfort is increasing exponentially, were all catalysts for the birth of this research project. In particular, noise is one of the major concerns that many companies want to come against, especially in the HVAC & Refrigeration sector. Indeed, noise coming from air conditioning systems can be perceived as very annoying. Thus, one of the main reasons this research is conducted is to increase consumer comfort in all applications where air conditioning noise, especially noise coming from expansion devices, is perceived as very disturbing. At the same time another motivation to conduct research in this area is to improve the understanding of flow induced noise. The objective of the thesis is to provide a basis for future scientists who would like to come against the problem of noise produced from expansion devices. Basic theories regarding noise and expansion devices are defined and explained. Subsequently the thesis demonstrates how the laboratory was designed and setup (the refrigerant used was R134a), including pressure, acceleration, and microphone measurements. The importance of the anechoic chamber will be shown. After it will be revealed the usefulness of the FFT to convert time domain measurements to frequency domain signals for detailed analysis. Initial measurements have been conducted and similarities between pressure and acceleration measurements will be investigated in the frequency range of interest (< 6 kHz). Lastly, preliminary flow visualization results are available to connect flow regimes to noise measurements.

Graduation Semester

2017-05

Type of Resource

text

Permalink

http://hdl.handle.net/2142/97633

Copyright and License Information

Copyright 2017 Andrea Santambrogio

Owning Collections