By A.S. Ginevsky, Y.V. Vlasov, R.K. Karavosov
Results of experimental study on aerodynamic and acoustic regulate of subsonic turbulent jets via acoustic excitation are provided. It used to be established that those keep an eye on equipment, originated through authors, not just can accentuate blending (by acoustic irradiation at low frequency), but in addition significantly ease it (at high-frequency irradiation). This study monograph offers the up to date result of the authors supplemented by means of different investigations performed in united states, Germany and nice Britain. The tools for the numerical simulation of subsonic turbulent jets less than acoustic excitation are defined intimately, and examples are reviewed of sensible purposes, together with relief of turbojet engine noise and acoustic keep watch over of self-sustained oscillations in wind tunnels.
Read Online or Download Acoustic Control of Turbulent Jets PDF
Best aerospace books
Завершая выкладывать (имеющееся у меня) публикации о японских ВВС времен Второй мировой войны, предлагаю вниманию заинтересованных читателей англоязычное издание о самолете A6M 0. Выпуск богато иллюстрирован, и даже слабо разбирающиеся в английском языке читатели найдут для себя что-то интересное.
Moment Library reproduction- San Diego Air and house Museum
This examine has declared goals: it provides the theoretical foundation for a provably excellent comparative technique for enjoyable flows (ICP) and jus tifies its program to jet and, particularly, rocket engines. this may be handled in components. half I bargains a standing quo document on present calculation tools, and compiles and explains in brief crucial info on chosen seasoned minent rocket engines.
- Short Stirling in action
- Aerofax Extra: Lockheed F117a Stealth Fighter (Aerofax Extras)
- The Luftwaffe Profile Series: Number 3: Heinkel He 219 UHU
- Manufacturing Technology for Aerospace Structural Materials
- Gee Bee Racers
Extra resources for Acoustic Control of Turbulent Jets
S0o / U o for x / d = 4 where 0 is the momentum loss thickness at the initial section of a laminar boundary layer (Fig. 10 for a jet under longitudinal acoustical excitation. 022 . ° 40 CHAPTER 2. 5 2 5 St Fig. 7. 4. 1 x/d Fig. 8. 5. 1. 5 O 500 1000 t. ls Fig. 9. Change in the Euler time correlation of the longitudinal velocity pulsations at the points x! d = 3, Y / d = O and x! 75 , 3) a radiation-free jet. 017 . This value is observed at a part of the circular jet mixing layer of the range up to x = 4d or x = (800 -1600)00 .
17 and L > 115 dB causes the sensible decrease of the velocity pulsations at the jet axis (by 15 - 18%); for the initial turbulent boundary layer similar decrease is achieved only for L = 120 - 130 dB. 4. 06. e. the partial turbulence suppression, is realized irrespective of the flow mode in the boundary layer of the nozzle outlet section. However, to realize the effect, one needs an increased level of acoustical excitation for turbulization of the initial boundary layer. 8 100 120 L, dB 100 120 L, dB Fig.
L OL/ZO I pauo where p. 10- Pa, p and a are the density and 5 sound speed in the flow at the nozzle edge respectively. 05 - 2%. 04 I---lr---:H--,E--+--+_--+---+--+_-__j 8 12 16 20 24 x/d Fig. 3. 10 4 , &0 = 1%, Uo = 20 rn/s, L = 120 dB). 0 characteristic for coherent structures near the end of the initial region (x I d = 3 - 5) and in the near-nozzle part ofthe mixing layer (xl d < 1). Consider some results of experiments illustrating the above effects for a circular jet. Fig. 1. 50] and Fig. 14].
Acoustic Control of Turbulent Jets by A.S. Ginevsky, Y.V. Vlasov, R.K. Karavosov