THERMO- AND FLUID MECHANICS LECTURE ÓBUDA UNIVERSITY THERMO- AND FLUID MECHANICS LECTURE Only using inside Dr. Ferenc Szlivka professor Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Kinematics and continuity 4. chapter Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Plain flow Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Streamlines around a semi sphere and bridge pillar Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Streamlines around a drop Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Streamlines around a drop looked from a moving system Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Unsteady streamlines Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Streamlines around an airfoil Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Hot jet flow Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Streamlines around a car Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. 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) Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Kármán vortex street Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Kármán vortex street in a wind tunnel Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Continuity law for a steady flow Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Continuity law in differential form Steady flow Constant density flow Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. 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. Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. 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. Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Solution: First we should calculate the magnitude of free area The area of window: The free area: The volume flow rate: Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. 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. Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. 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: Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. 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. Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. 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. Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. 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: Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Solution: b./ Let’s apply the politropic state equation: The politropic power is the next: Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Vorticity and potential vortex Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Potential or irrotational and vortex flows Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Potential vortex Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Vorticity, rotation, angular velocity y Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Vorticity, rotation in a 3D coordinate system Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4. Potential vortex and G, the circulation Dr. Szlivka: Thermo- and Fluid Mechanics 4.

Dr. Szlivka: Thermo- and Fluid Mechanics 4.