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The Power of Shape
Published in Patrick Hossay, Automotive Innovation, 2019
One of the more interesting ways to shape and trigger vorticies for reduced drag is lesser-used but worth examining as we think about the nature of airflow. The idea behind it is to intentionally trigger high-energy vorticies within the boundary layer as a way of avoiding premature separation. This may seem a bit counter-intuitive, triggering a form of turbulence to avoid separation into turbulence; but it works. We can do this with small blades on the surface, called vortex generators. This is not a new idea. Large aircraft have used vortex generators for decades to ensure airflow remain attached to the control surfaces of the wing.
Design of Wind Turbines
Published in Vaughn Nelson, Kenneth Starcher, Wind Energy, 2018
Vaughn Nelson, Kenneth Starcher
Vortex generators have been used to improve aerodynamic efficiency. Novel ideas for improving efficiency of blades include dimples (like golf balls), scales (like sharks), and bumps on leading edges (like tubercles on whales). There is always a trade-off between increased efficiency and construction costs for novel airfoils. The simple solution is to increase the blade length a little on conventional blades to collect the same energy.
Heat transfer enhancement and flow characteristics of internal cooling channels with slit vortex generators
Published in Numerical Heat Transfer, Part A: Applications, 2023
Siwei Tang, Gongnan Xie, Guohua Zhang, Bengt Sundén
With the wide application of gas turbines in the industry, the question of how to make the gas turbine achieve higher efficiency has been a concern for many researchers. Increasing the temperature of inlet fluid is a well-known method to increase efficiency of turbines. Nevertheless, the turbine blades might be damaged by the high temperature of the operating gas. Therefore, an effective turbine blade internal cooling channel is very important for the efficient operation of a gas turbine [1]. Many researchers have studied the application of fin turbulence, vortex generator, and jet impingement for internal cooling [2,3]. The vortex generator is a typical way to improve heat transfer among the many internal cooling systems. The basic principle of vortex generators is that they create vortices and disturb boundary layers to change the flow structure. Because longitudinal vortices transmit more heat at a certain pressure loss than transverse vortices, they are more efficient [4].
Review of component wise performance enhancement techniques for simple solar water heater
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Satish Kumar Dewangan, Neeraj Sunheriya, T RaviKiran
The vortex generator is used to provoke disturbances in the center of the main flow (contrast to fins which disturbs the boundary layer directly). This leads to the generation of the centrally induced vortices so that turbulence mixing is enhanced. This leads convective heat gain to the fluid contained within the absorber tubes or riser tubes. Vortex generators belong to the passive techniques for heat transfer enhancement. Most recently two valuable research have been done based on the longitudinal delta winglet pair (DWP).