1. Heat and Flow Technology I.
ÓBUDA UNIVERSITY
Heat and Flow Technology I.
Use only inside
Dr. Ferenc Szlivka
Professor
Dr. Szlivka: Heat and Flow Technology I_4

2. Kinematics and continuity 4. chapter

3. Plain flow

4. Streamlines around a semi sphere and bridge pillar

5. Streamlines around a drop

6. Unsteady streamlines

7. Streamlines around an airfoil

8. Hot jet flow

9. Streamlines around a car

10. The path line: the way of a particle.
The streamline: the line which is tangential to the velocity in every point of it.
The streak line: the line of the particles coming from the same point of the stream (of the space)

11. Kármán vortex street

12. Kármán vortex street in a wind tunnel

13. Continuity law for a steady flow

14. Continuity law in differential form
Steady flow
Constant density flow

15. The volume flow rate or discharge is the volume of fluid flowing past a section per unit time.
The mass flow rate is the mass of fluid flowing past a section per unit time.

16. Outflow through window with grille
Calculate the volume flow rate coming out through the windows!
The velocity of air is v= 4 m/s,
The length of the square is, H=2m.
The area of grille is Agr=1m2.

17. Solution: First we should calculate the magnitude of free area
The area of window:
The free area:
The volume flow rate:

18. Outflow through a rain grille
The air is flowing with v=2,6 m/s through a HELIOS type square rain grille.
The velocity vector and the normal vector of the area have an angle a=450 .
A length of the square is b=395 mm = 0,395m.
The free surface area is 80% of the whole area.

19. Solution: First we should calculate the magnitude free area
The velocity vector component projected to the normal vector of area
And the volume flow rate:

20. Continuitate in compressor
The air is flowing in the suction side with velocity.
It was measured the pressure and the temperature
of the incoming and outgoing air.

21. Data: Questions: a./ Calculate the velocity at the pressure side ( )!
b./ Calculate the power of the politropic state change between the pressure
and the suction side.

22. Solution:
a./ The mass flow rate are the same in the pressure and the suction side of the compressor:
The incoming density:
The outgoing density
From the densities we can calculate the velocity on the pressure side:

23. Dr. Szlivka: Fluid mechanics 4.
Megoldás:
b./ Let’s apply the politropic state equation:
The politropic power is the next:
Dr. Szlivka: Fluid mechanics 4.

24. Vorticity and potential vortex

26. Potential or irrotational and vortex flows

27. Potential vortex

28. Vorticity, rotation, angular velocity

29. Vorticity, rotation in a 3D coordinate system

30. Potential vortex and G, the circulation