materi fisika aplikasi

1. Fisika Aplikasi
Modified form of Bernoulli Equation
2022

2. Fluid is a substance which is capable of
flowing.
Fluid classification based on viscosity:
Ideal
• Fluids which don’t have
viscosity and are
incompressible are termed
as ideal fluid such fluid do
not offer shear resistance.
Real
• Fluids which do posses
viscosity are termed as real
fluids. These fluids always
offer shear resistance.

3. Real
fluid

4. • Non-Newtonian fluids change their viscosity
or flow behaviour under stress. If you apply a
force to such fluids (say you hit, shake or jump
on them), the sudden application of stress can
cause them to get thicker and act like a solid,
or in some cases it results in the opposite
behaviour and they may get runnier than they
were before. Remove the stress (let them sit
still or only move them slowly) and they will
return to their earlier state.

5. example
• Tomato sauce on the bottle. When you turn
the bottle upside down, nothing comes out.
So what do you do? You shake or hit the
bottle. This causes the tomato sauce to
become more liquid and you can easily squirt
some out. In this case, the sauce’s viscosity
decreases and it gets runnier with applied
stress.

6. Non-Newtonian fluids

7. Behaviour of a Real Fluid
• Turbulent shear equation
• Modified form of Bernoulli Equation:
– Velocity Head Coefficient
– Energy Head Loss
– External Energy Conversion

8. Turbulent shear equation
𝜏𝑡𝑢𝑟𝑏 = 𝜇𝑡𝑢𝑟𝑏
𝑑𝑢
𝑑𝑦
𝜏𝑡𝑢𝑟𝑏 : turbulent shear stress
𝜇𝑡𝑢𝑟𝑏 : turbulent viscosity
𝑑𝑢
𝑑𝑦
: velocity gradient (rate of change of velocity
across the path)

9. Total shear stress:
𝜏𝑡𝑜𝑡𝑎𝑙 = (𝜇 + 𝜇𝑡𝑢𝑟𝑏)
𝑑𝑢
𝑑𝑦

10. Bernoulli Equation
Pressure energy
Kinetic energy
Potential energy

11. Modified form of Bernoulli Equation

13. Contoh aplikasi: manajemen saluran air

14. Modified form of Bernoulli Equation

15. Contoh: determine the head loss

16. 𝑣1 = 𝑣2
𝑧1 +
𝑃1
𝜌𝑔
= 2,5 𝑚
𝑧2 +
𝑃2
𝜌𝑔
= 3 𝑚
2,5 = 3 + ℎ𝑙𝑜𝑠𝑠
ℎ𝑙𝑜𝑠𝑠 = −0,5 𝑚

17. Modified form of Bernoulli Equation