PPT: Turbulent Flow | Fluid Mechanics for Mechanical Engineering PDF Download

 Page 1


INTRODUCTION:
? Laminar Flow: In this type of flow, fluid particles moves along smooth straight parallel
paths in layers or laminas, with one layer gliding smoothly over an adjacent layer, the paths
of individual fluid particles do not cross those of neighbouring particles.
? Turbulent Flow: In turbulent flow, there is an irregular random movement of fluid in
transverse direction to the main flow. This irregular, fluctuating motion can be regarded as
superimposed on the mean motion of the fluid.
Page 2


INTRODUCTION:
? Laminar Flow: In this type of flow, fluid particles moves along smooth straight parallel
paths in layers or laminas, with one layer gliding smoothly over an adjacent layer, the paths
of individual fluid particles do not cross those of neighbouring particles.
? Turbulent Flow: In turbulent flow, there is an irregular random movement of fluid in
transverse direction to the main flow. This irregular, fluctuating motion can be regarded as
superimposed on the mean motion of the fluid.
Laminar
Transitional
Turbulent
Page 3


INTRODUCTION:
? Laminar Flow: In this type of flow, fluid particles moves along smooth straight parallel
paths in layers or laminas, with one layer gliding smoothly over an adjacent layer, the paths
of individual fluid particles do not cross those of neighbouring particles.
? Turbulent Flow: In turbulent flow, there is an irregular random movement of fluid in
transverse direction to the main flow. This irregular, fluctuating motion can be regarded as
superimposed on the mean motion of the fluid.
Laminar
Transitional
Turbulent
Page 4


INTRODUCTION:
? Laminar Flow: In this type of flow, fluid particles moves along smooth straight parallel
paths in layers or laminas, with one layer gliding smoothly over an adjacent layer, the paths
of individual fluid particles do not cross those of neighbouring particles.
? Turbulent Flow: In turbulent flow, there is an irregular random movement of fluid in
transverse direction to the main flow. This irregular, fluctuating motion can be regarded as
superimposed on the mean motion of the fluid.
Laminar
Transitional
Turbulent
? Types of flow depend on the Reynold number ,                    ?Vd
Re = --------
µ 
? Re < 2000 – flow is laminar
? Re > 2000 – flow is turbulent
? 2000 < Re < 4000 – flow changes from laminar to turbulent.
Page 5


INTRODUCTION:
? Laminar Flow: In this type of flow, fluid particles moves along smooth straight parallel
paths in layers or laminas, with one layer gliding smoothly over an adjacent layer, the paths
of individual fluid particles do not cross those of neighbouring particles.
? Turbulent Flow: In turbulent flow, there is an irregular random movement of fluid in
transverse direction to the main flow. This irregular, fluctuating motion can be regarded as
superimposed on the mean motion of the fluid.
Laminar
Transitional
Turbulent
? Types of flow depend on the Reynold number ,                    ?Vd
Re = --------
µ 
? Re < 2000 – flow is laminar
? Re > 2000 – flow is turbulent
? 2000 < Re < 4000 – flow changes from laminar to turbulent.
? Magnitude of Turbulence :
- It is the degree of turbulence, and measures how strong, violent or intence 
the turbulence.
- Magnitude of Turbulence  = Arithmetic mean of root mean square of turbulent       
fluctuations
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