This document defines and describes different types of fluid flows: - Steady flows have constant fluid properties over time, while unsteady flows have properties that change over time. Laminar flows move in straight, parallel lines while turbulent flows move chaotically. - Uniform flows have constant velocity regardless of position, while non-uniform flows have varying velocity. - Compressible flows have changing density, while incompressible flows have constant density.

1. •S T E A D Y / U N S T E A D Y F L O W
•U N I F O R M / N O N - U N I F O R M F L O W
•L A M I N A R / T U R B U L E N T F L O W
•D I M E N S I O N A L F L O W S
•C O M P R E S S I B L E / I N C O M P R E S S I B L E F L O W
•T A B U L A R P R E S E N T A T I O N
Type of Fluid Flows

2. Steady/Unsteady Flow
 Steady Flow – The steady flow is a type of flow in which the fluid characteristics like
velocity, pressure, density etc at a particular point doesn’t changes with time. (Example –
P1 (Constant)(Location1) = P2(Constant)(Location2)
 Unsteady Flow - Where as unsteady flow is defined as a type of flow in which fluid
characteristics changes with respect to time as particular point of time. (Example –
P1(Variable)(Location1), P2(Constant)(Location2))
 Quasi-Steady Flow – It is a type of flow in which fluid characteristics doesn’t changes at
particular point with respect to time but characteristics changes at different location.
(Example – P1(Constant)(Location1), P2(Constant)(Location2))
Fig1

3. Uniform/Non-Uniform Flow
 Uniform Flow – It is defined as a type of flow in
which, at given time velocity doesn’t changes with
respect to space (i.e length of direction of the flow).
 Non-Uniform Flow – Where as, non-uniform flow is
a type of flow in which, at given time velocity
changes with respect to space.
Fig2

4. Laminar/Turbulent Flow
 Laminar Flow – It is a type of flow in which fluid particles move along in a well defined
path or streamline and all streamlines are straight and parallel.
 Turbulent Flow – It is a type of flow in which fluid particles move in a zigzag way, due to
which eddies formation take place which is responsible for high energy losses.
 Note – For pipe flow, type of flow is determined by non-dimensional number Reynolds
Number. If Reynolds Number is less than 2000, the flow is called Laminar Flow and if
Reynolds Number is greater than 4000, the flow is called Turbulent Flow. If number is
between 2000-4000 flow can be treated as either Laminar or Turbulent.
Fig3

5. Dimensional Flows
 One Dimensional Flow – It is type of flow in which velocity is a function of time
and flow is in one space co-ordinate. Example (x)
 Two Dimensional Flow – It is similar to one dimensional flow but flow is in
rectangular space coordinate and velocity is a function of time. Example (x,y)
 U = f(x), v=0 and w =0
 Where, u, v & w are velocity component is x, y directions representatives.
Fig4 – Example of One Dimensional
Flow
Fig5 – Example of Two Dimensional
Flow

6. Compressible/Incompressible Flow
 Compressible Flow – Compressible flow is a type of flow in which
density of fluids changes from a point to point.
 Incompressible Flow – Where as, in compressible flow is a type of flow
in which density of fluid doesn’t changes from a point to point.
 Generally gases are compressible fluid flow and liquids are
incompressible fluid flow.
Fig6

7. Tabular presentation of Fluids
Types of fluids Density Viscosity
Ideal Fluids Constant Zero
Real Fluids Variable Non Zero
Newtonian Fluids Constant/Variable T = u(du/dy)
Non Newtonian Fluids Constant/Variable T ≠ u(du/dy)
Incompressible Fluids Constant Non Zero/Zero
Compressible Fluids Variable Non Zero/Zero

8. Sources
 Fig1https://blog.softinway.com/unsteady-flow-simulation-in-hydraulic-systems/
 Fig2http://stream1.cmatc.cn/pub/comet/HydrologyFlooding/streamflow/comet/hydro/basic/Routing/print_version/
03-streamflow_characteristics.htm
 Fig3https://www.physiologyweb.com/figures/physiology_illustration_Gxr9bSdjRij69DSavoTbjWtiQ44Pw3aM_lamin
ar_versus_turbulent_flow_in_blood_vessels.html
 Fig4http://www-mdp.eng.cam.ac.uk/web/library/enginfo/aerothermal_dvd_only/aero/fprops/cvanalysis/node7.html
 Fig5http://www-mdp.eng.cam.ac.uk/web/library/enginfo/aerothermal_dvd_only/aero/fprops/cvanalysis/node7.html
 Fig6https://www.chegg.com/homework-help/definitions/incompressible-and-compressible-flow-5