This Small Business Innovation Research Phase I project will cost effectively optimize the integration of Sinhatech's patented flexible-skin Deturbulator with vehicle drag-reducing wind deflectors, aircraft wings and airfoils. The Deturbulator is a passive flexible-skin large-eddy breakup device for mitigating turbulent mixing in separated flows. Sinhatech?s recently developed self aligning Deturbulator-enhanced wind-deflector (DEWD) aero-drag reducing retrofit has demonstrated 9-16% fuel economy increase on some trucks and vans. Market acceptance will require speeding up current test-and-modify Deturbulator installation optimization. The impediment has been a lack of cost effective CFD tools capable of modeling the Deturbulator. A joint effort with Mississippi State University has just demonstrated that user specified limits on mixing lengths in a turbulence model can mimic Deturbulator induced flow modifications in an efficient RANS code. In Phase-1 detailed wind-tunnel measurements on a DEWD will guide development of universal mixing-length modification rules based on easily quantifiable features of the Deturbulator and the flow-field. This procedure will also be verified against experimental data from a Deturbulator treated low-speed airfoil. Flight performance tests with Deturbulator treated wings have yielded 18% increase in lift to drag. CFD guided optimization will enable designing extreme lift-to-drag airfoils and wings and virtually streamlined vehicles with uncompromised functionality.
The proader potential/commercial impact of the proposed project will immediately enable 5-10% fuel saving and greenhouse gas emission reduction by inexpensively streamlining trucks and automobiles without impacting functionality. Optimized Deturbulators payback in 2-3 months compared to 24-months for competing aero-retrofits, creating a $3-Billion market. Deturbulator treatments can enhance commercial realization of currently evolving fast, short takeoff and landing high-endurance zero-emission battery powered aircraft with acceptable payload capacity and range. Beginning with enabling tactical UAV platforms capable of providing round-the-clock low altitude surveillance, an estimated $10 billion market, this will revolutionize the $3 Trillion commercial aviation industry at all levels. This includes 20% or more fuel savings and emission reduction for long haul jet transport by applying the treatment to wings, stabilizers and high bypass turbine engine fan blades and propeller blades. The project will also enable a similar approach for enhancing wind-turbine blade efficiency and fatigue life, improving wind-power?s cost advantage for more accessible sites. It can provide an order of magnitude leap in maximum speed, endurance or fuel savings over aggressive laminar flow wing designs or competing surface treatments like riblets which strive to reduce turbulent skin friction.
Normal 0 false false false EN-US X-NONE X-NONE Intellectual Merit Maximizing fuel efficiency of road and air vehicles requires minimizing air resistance or drag beyond what current streamlining practice allows. Some vehicle types, such as trucks and vans cannot be adequately streamlined since their functionality requires angular shapes which an airflow cannot follow. Separated airflow occurs behind corners, such as over the open bed behind the cab of a pickup truck. The separated flow is dominated by rapidly churning turbulent vortices which dissipate flow energy, thereby increasing drag. To mitigate such situations Sinhatech has invented the flexible-surface "Deturbulator" described below. Strategically located flush mounted Deturbulator patches interact with the airflow converting these regions of rapidly churning air into more stagnant air pockets. The stagnant air masses fill up the voids in the outline of the body. This smoothes the surface for the oncoming airflow thereby lowering drag. Layers of Deturbulator enabled stagnant air can also be added to change the effective shape of aircraft wings in order to simultaneously increase lift while reducing drag. The Deturbulator consists of a thin flexible composite film spanning a row of ridges on the surface of the solid body. Fluctuations inherent in a turbulent or transitory airflow over the body. drive waves on the skin similar to a fluttering flag. When the waves pass over the ridges they are broken up. This effect is subsequently reflected back into the airflow and breaks up the large eddies responsible for the fluctuations. In order to utilize the Deturbulator in this manner without creating adverse effects the design has to be optimized through a pain staking trial and error procedure. This has prevented wide scale adoption of this technology in spite of demonstrated 20% drag reduction for trucks and 18% increase in sailplane lift-to-drag ratio. This SBIR project was aimed at removing this impediment by mimicking the large-eddy breakdown process in a fast running Reynolds Averaged Navier Stokes (RANS) computational fluid dynamics model with the help of Mississippi State University. Key outcomes A Length Scale Limiter (LSL) was incorporated into an existing turbulence model in a RANS computer code. This was able to model effect of Deturbulator. The Deturbulator’s interaction in the presence of other features, such as modification of the shape could also be modeled. A focal point of this project was optimizing wind deflectors enhanced with Deturbulator surfaces. We were able to optimize orientation and identify important physics of the modified separated flow. This was achieved through a combination of simplified computational fluid dynamics modeling and testing in the wind tunnel. This approach can be extended in Phase-II to optimize the shape of the Deflector to further enhance efficacy. The accuracy of drag reduction predicted by the LSL modified 2-equation turbulence model based RANS CFD model is still inadequate. However, the code can correctly identify trends in other quantifiable features of the flow. The length of the separated region is such a feature. These features were used to guide iterative optimization. We demonstrated 15% reduction in drag using optimized Deturbulator Enhanced Deflectors to virtually streamline a pickup truck bed. Also showed 13% drag reduction for a hatchback/SUV. Both cannot be streamlined by other means without compromising functionality and have attracted funding from a major global automobile manufacturer. We demonstrated 20% L/D increase on the Luciole MC-30E Li-Po battery powered green light sports aircraft by Deturbulator treatment of wings. The aircraft subsequently established new FAI certified speed and distance records in the electric powered microlight category (www.aeroskylux.aero). Broader impacts: The proposed project has enabled 5-10% fuel saving and greenhouse gas emission reduction by inexpensively streamlining trucks and automobiles without impacting functionality. Optimized Deturbulators can payback in 2-3 months compared to 24-months for competing aero-retrofits, creating a potential $3-Billion market. Deturbulator treatments can enhance commercial realization of currently evolving fast, short takeoff and landing high-endurance zero-emission battery powered aircraft with acceptable payload capacity and range. Beginning with enabling tactical UAV platforms capable of providing round-the-clock low altitude surveillance, an estimated $10 billion market, this can revolutionize the $3 Trillion commercial aviation industry at all levels. This includes 20% or more fuel savings and emission reduction for long haul jet transport by applying the treatment to wings, stabilizers and high bypass turbine engine fan blades and propeller blades. The project will also enable a similar approach for enhancing wind-turbine blade efficiency and fatigue life, improving wind-power’s cost advantage for more accessible sites. It can provide an order of magnitude leap in maximum speed, endurance or fuel savings over aggressive laminar flow wing designs or competing surface treatments like riblets which strive to reduce turbulent skin friction. The project has directly trained a minority Aerospace Engineering graduate and employed an underrepresented African American technician.
