PDF Publication Title:
Text from PDF Page: 108
critical value (the critical Mach number, Mc), the total drag coefficient increases abruptly. Nevertheless, if M∞ is just slightly above Mc, shock waves appearing in the flow field remain relatively weak, since the maximum Mach number in the flow is relatively close to one. For a population of airfoils of given relative thickness, shock waves will be more or less strong according to the particular shape of an individual; individuals closest to the global optimum, i.e. with the lowest drag coefficient, are expected to produce particularly weak shocks or, eventually, a completely shock-free flow. In the latter case, CD exactly equals zero for all airfoil shapes such that Mmax≤1, where Mmax is the maximum Mach number in the flow-field, and a continuous subset of global optima exists. Of course, this is due to limitations of the adopted flow model, which excludes viscous effects from considerations. For this reason, it was chosen to optimize the airfoil shape for flow conditions somewhat above the critical ones, in order to get supercritical flow for all individuals in the search space and, consequently, to be able to select a unique global optimum. In practice, because of numerical errors introduced by the numerical scheme and boundary conditions, CD is not exactly zero even for completely subsonic flow-fields, but takes instead small positive values. In order to distinguish between subcritical and supercritical airfoils, a numerical check on the flow maximum Mach number is introduced, and CD is forced to be zero if Mmax≤1. For supercritical flows characterized by strong shock waves, contribution of numerical errors to the total drag is generally negligible. Problems can arise for flow-fields characterized by very weak shock waves, i.e. for individuals close to the global optimum. For these individuals, numerical drag can represent a considerable amount of the total drag if the numerical evaluation of the fitness function is not sufficiently accurate; conversely, the more accurate is the numerical scheme and the finer the computational grid, the smaller the numerical error on CD. Firstly, two optimization runs are performed using different randomly-generated starting populations. For each run, the GA-driven population appears to have reached a stabilized optimal (minimal) value of the drag coefficient after the prescribed number of generations: the maximum and mean value of the drag coefficient in the final population of airfoil shapes are almost the same in each case, which hopefully indicates that the algorithm has converged to a population of almost identical geometries. Nonetheless, optimal airfoils obtained in the two runs display considerable geometric differences, precisely, about 8%, based on the distance measure ((Eq. 19). Since both optimization runs provide stabilized 107PDF Image | ANALYSIS AND OPTIMIZATION OF DENSE GAS FLOWS: APPLICATION TO ORGANIC RANKINE CYCLES TURBINES
PDF Search Title:
ANALYSIS AND OPTIMIZATION OF DENSE GAS FLOWS: APPLICATION TO ORGANIC RANKINE CYCLES TURBINESOriginal File Name Searched:
phd_thesis_PM_CONGEDO.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 |