PDF Publication Title:
Text from PDF Page: 064
Chapter4. DataAnalysis 52 At 5 kHz, three distinct sound sources can be observed radiating into the forward arc, whereas SODIX locates the sources more uniformly for the downstream mi- crophones. This implies some form of wave interference in the forward quadrant which results in the trident shape. Beginning with the 5 kHz plot, the frequency response deviation of the microphones described in Sect. 3.2.1 can be seen. At 10 kHz, aliasing occurs, causing SODIX to falsely take away source energy from the main source and add it to the aliasing sources. In addition, the last two plots show clearly, that the source events start almost exactly at the nozzle outlet x = 0, as there is no source detected upstream of this plane. This implies that there are no significant noise sources on the aeroengine nacelle, but only in the free jet, which is to be expected without employing a simulated flight stream. Sideline ICAO reference point with wing installation Figure 4.9 shows the comparisons of installed (DLR 435) and isolated (DLR 317) jet. The uninstalled wing case is always subtracted from the installed case, so that positive values, represented in red, imply that the installed case is louder. The SPL difference between installed and isolated test configurations is generally about 12 dB, which is a rather significant increase. The aliasing effect becomes more prominent as well. In the low-frequency domain, additional sound sources occur primarily upstream of the nozzle and can most certainly be attributed to either sound wave reflection from the wing or surface/flow interactions. How- ever, as incidence and exit angles must correspond, the forward reflection would require an unusual negative incidence angle. Therefore, the physical validity of the 250 Hz plot is questionable. The high-frequency plots exhibit more expected behaviour. For the 1250 Hz TOB, there are two different areas with increased sound pressure, the first right at the nozzle radiating into the aft quadrant, the second in close proximity to the nozzle being picked up by almost the full linear array. At this frequency, the sources are most likely medium-scale eddies formed on the underside of the wing due to wall shear stress. These vortices only occur within a small frequency range; for higher frequencies the sources become more well-defined. On the latter two plots, there are two distinct noise sources. The first is on the same position as the one in the 1250 Hz plot, meaning that there is a turbulent event emitting a broadband noise that spans over all TOB. The second source travels further downstream with increasing frequency. As eddies tend to grow with increasing travel distance, thePDF Image | Investigation of wing installation effects on the sound field of a model jet engine
PDF Search Title:
Investigation of wing installation effects on the sound field of a model jet engineOriginal File Name Searched:
thesis-wing-install-effects-jet-engine.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |