From 03807bcd459be85741f78cdacfbaade31be4dc27 Mon Sep 17 00:00:00 2001 From: cfvgx Date: Tue, 24 Sep 2024 20:55:35 +0200 Subject: [PATCH] Finished notes for 1st video --- Introduction to fluid dynamics.md | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/Introduction to fluid dynamics.md b/Introduction to fluid dynamics.md index 7219275..0bd1017 100644 --- a/Introduction to fluid dynamics.md +++ b/Introduction to fluid dynamics.md @@ -11,5 +11,31 @@ Let lambda be the mean free path, L a characteristic dimension of the problem Kn = lambda/L -Hypothesis : -If Kn<<1, it is possible to use a model based on the continuum hypothesis \ No newline at end of file +Hypothesis: +If Kn<<1, it is possible to use a model based on the continuum hypothesis + +That hypothesis is often valid, but not always. Within this course's scope, this hypothesis is always valid. + +## Types of flows + +Three ways flows can be be split: + +### (Un)Steady flows +Steady: flow variables do not depend on time. + +d/dt = 0 + +### (In)compressible flows +A flox can be considered incompressible is the Mach number is low enough: + +Let v be the flow velocity, c be the celerity of sound + +Approx. M = v/c <= 0.3 + +### Turbulent or laminar flows + +Turbulent flows : flow variable are stochastic and vary with space and time. This happens when the Reynolds number is high enough : + +Re = rho*v*D/mu > 2500 (for a tube) + +Turbulent flows happen often but we'll find ways get around it. \ No newline at end of file