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A pulse sequence in MRI is a series of radiofrequency pulses and gradient magnetic fields designed to generate specific types of image contrast and data acquisition. It determines the timing, duration, and order of these pulses to manipulate nuclear spin properties, enabling the visualization of different tissue characteristics and functionalities.
Fluid dynamics is a branch of physics that studies the behavior of fluids (liquids and gases) in motion and the forces acting on them. It is essential for understanding natural phenomena and designing systems in engineering disciplines, including aerodynamics, hydrodynamics, and meteorology.
Vortex shedding is a fluid dynamics phenomenon where alternating low-pressure vortices are formed downstream of a bluff body in a flow, causing oscillating forces on the body. This can lead to structural vibrations and is a critical consideration in the design of structures like bridges, chimneys, and tall buildings to avoid resonance and potential failure.
Concept
Vorticity is a measure of the local rotation in a fluid flow, representing the tendency of fluid elements to spin around a point. It is a crucial concept in fluid dynamics, helping to understand complex flow patterns such as turbulence, cyclones, and eddies.
Concept
Turbulence is the chaotic, unpredictable flow of fluids characterized by vortices, eddies, and rapid changes in pressure and velocity. It plays a critical role in various natural and industrial processes, affecting weather patterns, aircraft performance, and energy efficiency in systems like pipelines and turbines.
Boundary Layer Theory describes the thin region adjacent to a solid surface where viscous forces are significant, affecting the flow velocity and pressure distribution. It is crucial for understanding drag, heat transfer, and aerodynamic performance in fluid dynamics applications.
The Navier-Stokes Equations are a set of nonlinear partial differential equations that describe the motion of fluid substances such as liquids and gases. They are fundamental to fluid dynamics and are used to model weather patterns, ocean currents, and airflow around wings, among other applications.
Helmholtz's Theorems provide a foundational framework in fluid dynamics for understanding the behavior of vortex flows. They describe how vortices behave in an ideal fluid, including the conservation of circulation and how vortex lines move with the flow.
Potential flow theory is a mathematical approach used to analyze fluid flow where the fluid is considered incompressible and irrotational, allowing the use of potential functions to simplify complex flow problems. It is particularly useful in aerodynamics and hydrodynamics for modeling idealized flow patterns around objects without accounting for viscosity effects.
The Coriolis effect is a phenomenon that causes moving air and water to turn and twist due to Earth's rotation, influencing weather patterns and ocean currents. It is crucial for understanding the dynamics of large-scale atmospheric and oceanic circulations, such as trade winds and cyclones.
Bound vortices are circulating flows that form around aerodynamic bodies, effectively enabling lift generation by altering pressure distribution along the surface. These vortices are permanent and closed, remaining attached to the aerofoil and play a crucial role in sustaining lift through the plane's movement in fluid dynamics.
Lift distribution refers to the manner in which aerodynamic lift is spread across the wingspan of an aircraft, a critical aspect for ensuring optimal aerodynamic efficiency and structural integrity. Understanding and optimizing Lift distribution helps in minimizing induced drag and enhancing the aircraft's performance, particularly in terms of lift-to-drag ratio and stability.
Propeller efficiency is a measure of how effectively a propeller converts the engine power into thrust, impacting both performance and fuel economy of the vehicle. It is influenced by factors such as blade design, angle of attack, and operational conditions like speed and altitude.
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