Fluid dynamics

In <a href="/facts/Physics/a7aH2y08">physics</a>, <a href="/facts/Physical_chemistry/WqwnJjRM">physical chemistry</a> and <a href="/facts/Engineering/RFVg8H3I">engineering</a>, fluid dynamics is a subdiscipline of <a href="/facts/Fluid_mechanics/NIy4tRfE">fluid mechanics</a> that describes the flow of <a href="/facts/Fluid/tMQ46Tmz">fluids</a> – <a href="/facts/Liquid/t9GkLWzt">liquids</a> and <a href="/facts/Gas/hVVAoodV">gases</a>. It has several subdisciplines, including <a href="/facts/Aerodynamics/Cn6Lnl3H">aerodynamics</a> (the study of air and other gases in motion) and hydrodynamics (the study of water and other liquids in motion). Fluid dynamics has a wide range of applications, including calculating <a href="/facts/Force/533Q1uzq">forces</a> and <a href="/facts/Moment_(physics)/WvgxtdhP">moments</a> on <a href="/facts/Aircraft/EhC4mBep">aircraft</a>, determining the <a href="/facts/Mass_flow_rate/v2DrbGvq">mass flow rate</a> of <a href="/facts/Petroleum/IQV0bHVd">petroleum</a> through <a href="/facts/Pipeline_transport/gEmKcFhD">pipelines</a>, <a href="/facts/Weather_forecasting/nzqyMFCa">predicting weather patterns</a>, understanding <a href="/facts/Nebula/hG6coklY">nebulae</a> in <a href="/facts/Interstellar_space/R3LRKyFs">interstellar space</a>, understanding large scale <a href="/facts/Geophysical_fluid_dynamics/n5huhjfM">geophysical flows</a> involving oceans/atmosphere and <a href="/facts/Nuclear_weapon_design/gw0LEc74">modelling fission weapon detonation</a>.
Fluid dynamics offers a systematic structure—which underlies these <a href="/facts/Practical_disciplines/13h5uYCH">practical disciplines</a>—that embraces empirical and semi-empirical laws derived from <a href="/facts/Flow_measurement/PvbEEcE8">flow measurement</a> and used to solve practical problems. The solution to a fluid dynamics problem typically involves the calculation of various properties of the fluid, such as <a href="/facts/Flow_velocity/amIT4Ht8">flow velocity</a>, <a href="/facts/Pressure/eyc37GRG">pressure</a>, <a href="/facts/Density/92p6hh9I">density</a>, and <a href="/facts/Temperature/QyGe4gmj">temperature</a>, as functions of space and time.
Before the twentieth century, "hydrodynamics" was synonymous with fluid dynamics. This is still reflected in names of some fluid dynamics topics, like <a href="/facts/Magnetohydrodynamics/7mQbJPPD">magnetohydrodynamics</a> and <a href="/facts/Hydrodynamic_stability/5hnxSFjo">hydrodynamic stability</a>, both of which can also be applied to gases.

Fluid dynamics open-in-new

Fluid dynamics