Noise reduction of a Mach 0.7–0.9 jet by impinging microjets

نویسندگان

  • Thomas Castelain
  • Jean-Christophe Béra
  • Michel Sunyach
چکیده

A global noise reduction of a high-subsonic jet is achieved by experimental use of an impinging microjets system. The microjet velocity relative to the main jet velocity, the longitudinal distance of injection and the number of microjets are the three parameters examined in order to obtain the maximum noise reduction. This optimized microjet configuration is obtained by a balance between low-frequency attenuation and high-frequency noise generation due to the interaction between the microjets and the main jet mixing layer. To cite this article: T. Castelain et al., C. R. Mecanique 334 (2006). © 2006 Académie des sciences. Published by Elsevier SAS. All rights reserved.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

طراحی و ساخت نازل جت چند گانه با هدف کاهش صدای ناشی از تفنگ های بادپاش

Background and aims: Discharging compressed air through conventional single jet nozzles or open pipes is a common jet noise in industry. This study is aimed to reduce air blow gun jet noise by designing and fabrication of multiple jet nozzle as a substitute for conventional single jet nozzles.  Methods: One of the most common commercial air blow gun equipped with a conventional single j...

متن کامل

Mach Number Effects on Jet Noise Sources and Radiation to Shallow Angles

A LL jets have noise generation due to turbulent mixing; such mixing leads to the production of Reynolds stresses, the source term within the Lighthill acoustic analogy [1]. In addition to this source, a jet that possesses coherent, large-scale structures that travel with velocities exceeding the local speed of sound will emit Mach wave radiation, a highly efficient noise production mechanism. ...

متن کامل

Experimental study and numerical simulation of three dimensional two phase impinging jet flow using anisotropic turbulence model

Hydrodynamic of a turbulent impinging jet on a flat plate has been studied experimentally and numerically. Experiments were conducted for the Reynolds number range of 72000 to 102000 and a fixed jet-to-plate dimensionless distance of H/d=3.5. Based on the experimental setup, a multi-phase numerical model was simulated to predict flow properties of impinging jets using two turbulent models. Mesh...

متن کامل

Control of Nozzle Flow Using Microjets at Supersonic Mach Regime

This article reports the active control of base flows using the experimental procedure. Active control of base pressure helps in reducing the base drag in aerodynamic devices having suddenly expanded flows. Active control in the form of microjets having 0.5 mm radius placed at forty-five degrees apart is employed to control the base pressure. The Mach numbers of the present analysis are 1.7, 2....

متن کامل

Aiaa-2000-2062 Linear Model of Mach Wave Suppression in a Dual-stream Jet

Reduction of Mach wave emission from a dual-stream jet is modeled via a linear temporal analysis in the frame of reference of the jet instability. The interface between the primary and secondary streams is simulated by a exible wavy wall with zero phase speed and arbitrary growth rate. The interface between the secondary and ambient streams is simulated by a vortex sheet. The secondary stream, ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2006