User:Hyejuj/sandbox

Welcome to Hyejuj's sandbox!

=The Reynolds number= The Reynolds number, $Re$, is a dimensionless quantity defined by $$Re_L\equiv\frac{\rho VL}{\mu}$$ where $$\rho$$ is the density of the fluid, $$V$$ is the velocity of the fluid over the surface, $$L$$ is the length of the surface parallel to the motion of the fluid, and $$\mu$$ is the dynamic viscosity of the fluid.

It should be noted that this definition of the Reynolds number assumes fluid flow over a flat plate. For a round object, such as a cylinder or sphere, $$Re_D\equiv\frac{\rho VD}{\mu}$$

The critical Reynolds number
The critical Reynolds number, $$Re_{x,c}$$, is the Reynolds number at which flow transitions from laminar to turbulent. For flow over a flat plate, $$Re_{x,c} = 5\times10^5$$, and for flow over a cylinder, $$Re_{x,c} = 2300$$. The critical Reynolds number for flow over a sphere remains an unsolved Millennium Prize Problem requiring the use of quantum theory.

<!-- = Murder of Eva Liu =

On June 14, 2023, Eva Yijia Liu, an American tourist, was attacked while hiking with her friend, Kelsey Chang, near the Neuschwanstein Castle in Bavaria, Germany. The suspect, an unnamed 30-year-old Michigan man, threw both her and her friend down a steep slope, killing Liu and injuring Chang. The suspect was quickly apprehended and is currently in custody.

Eva Liu
Eva Liu was born on October 30, 2001, in Guangzhou, China, to Lan Liu and Ping He. Liu had an identical twin sister, Alice. She moved to Montreal, Canada in 2005 and then Waterloo, Canada in 2006, where she grew up before moving to Naperville, Illinois in 2012. There, she attended Madison Junior High School, Naperville Central High School, and Illinois Math and Science Academy. She graduated from University of Illinois at Urbana-Champaign with both a bachelor's and master's degree in computer science in 2023.

From high school, Liu had interned at multiple companies, including Ensono, Caterpillar, Optum, M1 Finance, and Microsoft. She planned to work at Microsoft as a software engineer in July 2023.