The dimensionless turbulence diffusion constant and the dimensionless distance from the channel wall (0.01β€2/π»β€1) According to DNS π ππ=104 and anisotropic models.
Changes in the way turbulence is modeled lay the foundation for a clearer understanding and prediction of fluid behavior in complex situations. Professor Emeritus Bert Brouwers has developed a new turbulence model that relies on statistical principles rather than traditional empirical methods. This innovative approach, recently published in the journal Invention, offers significant improvements in the way scientists predict and model turbulence.
Unlike older turbulence models that relied on trial-and-error adjustments, Dr. Brouwers’ anisotropic turbulence model is based on fundamental principles of physics. “By using common rules rather than guesswork, the model makes it easier to understand how turbulence behaves in different situations,” explains Dr. Brouwers. The model simplifies complex aspects of turbulence, such as momentum and energy, the motion carried by fluid particles and how power propagates through the fluid, providing a more accurate and direct representation.
The scientists tested the model against highly detailed simulations of fluid flow, known as direct numerical simulation (DNS) of the Navier-Stokes equations, a method that captures every detail of fluid motion and found that its predictions were consistent with simulations. The results are very consistent. This is not the case with commonly used models, which often fail in specific scenarios. By linking turbulent behavior directly to factors such as velocity and flow gradients, which describe how quickly and in which direction a fluid changes, the new model can be more smoothly integrated into computer programs used to study fluid dynamics.
One of the most important advances is the replacement of customized calibration parameters, such as diffusion rates, the rate at which particles diffuse in a fluid, with universally applicable formulas derived from well-established physical constants. Dr. Brouwers emphasizes: βThis approach eliminates guesswork and ensures consistent results in different situations, making it a more reliable tool for engineers and researchers.β
Key highlights of the research include better predictions of how energy is distributed in turbulent flows, and insights into how non-uniform conditions in flow systems affect turbulence. The model also has practical applications in understanding heat and material transfer, describing how heat and materials such as chemicals or contaminants move through fluids in engineered systems. This could benefit industries such as aerospace, energy and environmental management.
Experts evaluated the model using the example of a fluid flowing between parallel surfaces. Predictions of factors such as wave velocity, velocity and direction changes due to turbulence, energy distribution and stress levels are in good agreement with observations from higher-order simulations. The model is unique in its clear mathematical structure that reduces computational effort without loss of accuracy.
This upgraded turbulence model has applications beyond engineering systems. Dr Brouwers noted that the general principles behind it mean it could solve challenges in areas such as climate modeling, where turbulence plays a key role in weather patterns and ocean currents. “The model’s adaptability makes it a valuable resource for solving a wide range of problems in science and industry,” he said.
Now, the wider scientific community has access to a model that not only provides greater accuracy but also eliminates the need for complex and often inconsistent calibrations. This work lays a solid foundation for further developments in turbulence research and opens the door to new possibilities for environmental and technological innovation.
Journal reference
Brouwers, JJH, βAnisotropic k-Ο΅ model based on general principles of statistical turbulence.β Invention, 2024.
About the author
Burt Browers was Born 1949 in Hull/Maastricht, The Netherlands. In 1972 he received a master’s degree in mechanical engineering with distinction from the Eindhoven University of Technology. He received his PhD from the University of Twente in 1976. Engineer/Urenco Amsterdam. In 1974 he became head of the Isotope Separation Research Department. In 1979 he joined Royal/Dutch Shell. First, he served as head of the offshore research group at the Exploration and Production Laboratory in Rijswijk. In 1983, he moved to London and became a clerk in economics. Hoving University of Technology, became professor of the Department of Mechanical Engineering and director of the Process Technology Teaching and Research Office. He retired from the university in 2014 to continue research on classical mechanics topics and advance his ideas in new technologies. Brouwers has made innovative contributions to science and technology. Combustion, Journal of Engineering Mathematics, Reliability Engineering, Ocean Engineering, Nuclear Technology, Fluid Physics, MDPI Journal of Fluids, Separation, Mathematics, Invention. Brouwers is the inventor of patented methods and equipment for separating particles and gases using the principles of centrifugation, fluid flow and diffusion. Know-how and intellectual property rights belong to the company he founded. Practical versions of the invention have been developed and implemented worldwide in collaboration with licensing companies. In 1999, Brouwers received the Dow Chemical Energy Award. He works as a short-term consultant for companies and institutions. He has supervised more than 200 engineering and advanced engineering degrees and more than 40 doctorates awarded by the University of Twente and Eindhoven University of Technology.
