Subj : The science behind skipping stones To : All From : ScienceDaily Date : Tue Jul 11 2023 22:30:30 The science behind skipping stones Researchers uncover dynamics of buoyant spheres and the formation of horizontal air cavities at the air-water interface Date: July 11, 2023 Source: American Institute of Physics Summary: An interdisciplinary team presents a study of the dynamics of buoyant spheres at the air-water interface. Their work reveals complex hydrodynamics involved in forming horizontal air cavities and the transition between floating and skipping. One of the team's key findings is that as the pulling force and speed of the spheres increase, their behavior becomes more irregular. They also discovered larger pulling angles result in different air-cavity lengths, larger skipping distances, and earlier water exit behavior. Facebook Twitter Pinterest LinkedIN Email ========================================================================== FULL STORY ========================================================================== Inspired by the need to safeguard marine animals and promote sustainable solutions within marine environments, an interdisciplinary team of researchers from King Abdullah University of Science and Technology in Saudi Arabia and Sofia University in Bulgaria are delving into the hydrodynamics of buoyant objects at the air-water interface. By studying these dynamics, their goal is to expand the understanding of fluid hydrodynamics and complex surface interactions -- and advance fields such as the design and performance of marine engineering systems, buoy systems, and underwater vehicles. In Physics of Fluids, from AIP Publishing, the team presents a study of the dynamics of buoyant spheres (think skipping stones) at the air-water interface. Their work revealed complex hydrodynamics involved in forming horizontal air cavities and the transition between floating and skipping. The study of fluidics and physics within the context of buoyancy involves several key principles: buoyancy, hydrodynamics, fluid resistance, and a Reynolds number. Buoyancy refers to the upward force exerted on an object immersed within a fluid, while hydrodynamics focuses on the motion of the fluid and its interactions with solid objects. Fluid resistance, or drag, occurs when an object moving through a fluid experiences resistance due to the friction between its surface and the fluid. This resistance depends on factors such as an object's shape, size, speed, and fluid properties. To further analyze fluid behavior, scientists use a dimensionless parameter, a Reynolds number, to determine the type of flow around an object. One of the team's key findings is that as the pulling force and speed of the spheres increase, their behavior becomes more irregular. "The spheres exhibit oscillatory motions, diving into the water, rising toward and piercing the water surface, and attaching underwater air cavities in a horizontal direction," said co-author Farrukh Kamoliddinov of KAUST. They also discovered larger pulling angles result in different air-cavity lengths, larger skipping distances, and earlier water exit behavior -- meaning that the pulling angle plays a significant role in shaping the hydrodynamics of the buoyant spheres. And the cavity maintains a steady horizontal motion at a constant velocity over a certain distance. The air cavity formation exhibits distinct features, including an inverted wing shape and a turbulent wake behind it. This steady and controlled horizontal motion of the cavity provides insight into complex fluid dynamics and opens the door to further exploration and applications. "Understanding buoyant sphere dynamics and cavity formation can inspire new designs and innovations in fields beyond marine engineering," said Kamoliddinov. "It can potentially lead to new novel propulsion systems, drag reduction strategies, fluidic propulsion systems, and fluidic devices that harness the characteristics of buoyant spheres." * RELATED_TOPICS o Matter_&_Energy # Nature_of_Water # Chemistry # Inorganic_Chemistry # Aerospace # Engineering # Transportation_Science # Automotive_and_Transportation # Aviation * RELATED_TERMS o Water_rocket o Speed_of_sound o Air_conditioning o Breaking_wave o Aircraft o Aerodynamics o Ice_core o Air_engine ========================================================================== Print Email Share ========================================================================== ****** 1 ****** ***** 2 ***** **** 3 **** *** 4 *** ** 5 ** Breaking this hour ========================================================================== * Revolutionary_Electric_Artificial_Muscles * Age_of_Universe:_26.7,_Not_13.7,_Billion_Years * City_Ground_Is_Deforming:_Buildings_Aren't_Ready * The_Sound_of_Silence?_People_Hear_It * 36-Million-Year_Geological_Cycle_Drives_... * Six_Foods_to_Boost_Cardiovascular_Health * Cystic_Fibrosis:_Lasting_Improvement * Artificial_Cells_Demonstrate_That_'Life_... * Advice_to_Limit_High-Fat_Dairy_Foods_Challenged * First_Snapshots_of_Fermion_Pairs Trending Topics this week ========================================================================== SPACE_&_TIME NASA Space_Missions Asteroids,_Comets_and_Meteors MATTER_&_ENERGY Nature_of_Water Materials_Science Civil_Engineering COMPUTERS_&_MATH Artificial_Intelligence Neural_Interfaces Computers_and_Internet ========================================================================== Strange & Offbeat ========================================================================== SPACE_&_TIME Reinventing_Cosmology:_New_Research_Puts_Age_of_Universe_at_26.7_--_Not_13.7_- -_Billion_Years Quasar_'Clocks'_Show_Universe_Was_Five_Times_Slower_Soon_After_the_Big_Bang First_'Ghost_Particle'_Image_of_Milky_Way MATTER_&_ENERGY Revolutionary_Self-Sensing_Electric_Artificial_Muscles Bees_Make_Decisions_Better_and_Faster_Than_We_Do,_for_the_Things_That_Matter_to Them These_Lollipops_Could_'Sweeten'_Diagnostic_Testing_for_Kids_and_Adults_Alike COMPUTERS_&_MATH Number_Cruncher_Calculates_Whether_Whales_Are_Acting_Weirdly AI_Tests_Into_Top_1%_for_Original_Creative_Thinking Researchers_Create_Highly_Conductive_Metallic_Gel_for_3D_Printing Story Source: Materials provided by American_Institute_of_Physics. Note: Content may be edited for style and length. ========================================================================== Journal Reference: 1. Farrukh Kamoliddinov, Ivan U. Vakarelski, Sigurdur T. Thoroddsen, Tadd T. Truscott. Skipping under water: Buoyant sphere hydrodynamics at the air- water interface. Physics of Fluids, 2023; 35 (7) DOI: 10.1063/5.0153610 ========================================================================== Link to news story: https://www.sciencedaily.com/releases/2023/07/230711133104.htm --- up 1 year, 19 weeks, 1 day, 10 hours, 50 minutes * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3) .