Aeroacoustic Measurements

Abstract

9R7. Aeroacoustic Measurements. - Edited by TJ Mueller (Dept of Aero and Mech Eng, Univ of Notre Dame, 112 Hessert Center, Notre Dame IN 46556-5684). Springer-Verlag, Berlin. 2002. 313 pp. ISBN 3-540-41757-5. $99.00.Reviewed by MG Prasad (Dept of Mech Eng, Stevens Inst of Tech, Hoboken NJ 07030).It is well known that experimental work plays an important role in acoustics. In particular, the acoustical measurements in the presence of airflow is challenging due to test conditions. This book deals with this challenging and important topic in acoustics namely aeroacoustics. The five chapters of the book deal with various aspects aeroacoustic measurements with applications. Chapter 1, on “Microphone measurements in and out of air stream,” deals with the acoustic characteristics of wind tunnels. The discussions include criteria for simulation of aeroacoustic test environment with requirements such as propagation effect, scaling, low background noise levels, etc. Chapter 2 presents “Beam forming in acoustic testing.” The use of beam forming technique and its applications in the modeling of wind tunnel noise with non-acoustic hard walls and free jets are discussed. Several beam forming algorithms with techniques for removing interference is discussed in this chapter. Chapter 3 covers “Aeroacoustic phased array testing in low speed wind tunnels.” A comprehensive treatment of the design and application of acoustic phased array measurement capability for low speed wind tunnels is presented. Various aspects of operation such as calibration, data handling, etc, are discussed. Chapter 4 is on “Source characterization by correlation techniques.” The characterization of acoustical sources using correlation techniques is presented. The chapter discusses various mathematical aspects through cross-correlation and coherence functions. Various examples including correlation measurements between surface pressure and far field acoustic pressure field data are included. The last chapter is “An anechoic facility for basic aeroacoustic research.” The chapter presents the design, construction, and performance evaluation of an anechoic wind tunnel facility for low speed and low turbulence applications. Use of such a facility to experimentally investigate fluid-solid interaction is discussed. A specific wind tunnel facility is described. As an example the use of the facility for a marine propeller response to inflow disturbance is discussed. All chapters are well presented. In summary, Aeroacoustic Measurements is a nice integration of presentations of various recognized contributors. The book deals with important issues in design and performance evaluation of wind tunnel test facilities, measurement techniques, and mathematical aspects. Nice photographs and figures are included. Each chapter has a large number of references. The book is recommended for libraries and all graduate students, researchers, and professionals in acoustics. In particular, those involved in experimental aeroacoustics will find this book very useful.