PDF Publication Title:
Text from PDF Page: 033
3.4. TURBINE PERFORMANCE UNDER PULSATILE FLOW 23 an electrodynamic shaker. Tests were performed at two different frequencies of the pulsatile flow. Different phase settings between the pressure pulse and the movement of the nozzle were also tested. An increase in shaft power output with up to 7% was achieved with the active control system, but the efficiency was lower for the turbine fitted with this type of active control system. A better design is to active control the incidence angle of the vanes in a vaned nozzle. Rajoo & Martinez-Botas (2007) studied the performance of mixed flow turbines with moveable nozzle vanes. The movement of the nozzle vanes was controlled in both a passive way and in an active way with an actuator. In the passive system, an increasing pressure in the volute opened the vanes against a pre-loaded spring, and when the pressure decreased, the vanes were retracted. In this way, an increased area is obtained at high pressure, while the area is decreased at lower pressure. The passive system increased the shaft power output (with 36% for the best case) during the period of the pulse when the mass flow was low, but reduced the maximum power. The cycle averaged power was lower compared to a turbine with fixed vanes. Still the efficiency was better for the turbine with a passive control system. For the active system, with a forced movement of the vanes, a small improvement of the efficiency was achieved. The authors also concluded that of the tested control systems, a passive system with moveable nozzle vanes is probably the most beneficial system, especially for IC engines working with a narrow speed range. When computing the isentropic efficiency and U/Cs, it is common to as- sume that the pressure at the outlet of the turbine is constant during the pulse. This assumption can be doubted; special for small turbines with a size that is common for automotive applications. Capobianco & Marelli (2005) in- vestigated the unsteady pulsatile flow in a four to one exhaust manifold and a nozzle-less radial turbine, and one of the conclusions was that the flow un- steadiness at the turbine outlet cannot be neglected due to the fact that the measured pressure downstream of the turbine was not constant over a pulse period. The amplitude of the pressure variations was approximately 0.3 bar, and the amplitude of the pulse at the inlet to the turbine was for this case approximately 1.0 bar. The amplitude of the pressure variations downstream of the turbine also increased when the waste-gate valve was opened, since the maximum pressure before the turbine was higher, due to an increased mass flow through the system. Capobianco & Gambarotta (1990) also studied the effects of different waste-gate valve opening areas on the pressure pulses upstream and downstream of the turbine, and the results showed that the pressure pulses at the turbine inlet were unaffected by the waste-gate valve opening, while the pressure at the outlet of the turbine had a high frequency oscillation superim- posed. The frequency was about 3 kHz, but since neither the blade number nor the rotational speed of the wheel was specified in the report, no conclusion ofPDF Image | Numerical computations of the unsteady flow in a radial turbine
PDF Search Title:
Numerical computations of the unsteady flow in a radial turbineOriginal File Name Searched:
radial-turbine-unsteady-flows.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 |