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TERM PROJECT III 

THREE DIMENSIONAL FLOW IN A CUBICAL CAVITY  

Introduction

The object of this project is to create a cube with linear dimension of L cm and obtain a

CFD solution generating a uniform structured mesh of size 30x30x30 in two cases are

cavity with a moving wall and thermal cavity.

Parameters

L = 8 cm V = 4 m/s TH = 365 K TC = 335 K

Case A

Top wall of the cavity moves in the x direction

with velocity V. The remaining 5 walls are

stationary. The driving force of the clockwisemotion in the cavity is the moving wall.

  Viscosity μ=0.001 kg/ms

  Density ρ=1 kg/m3. 

  Area = 0.0064 m2 

Case B

The left (hot) wall of the cavity is

kept at a uniform temperature of TH

and the right (cold) wall of the

cavity is at temperature TL. The

remaining 4 walls of the cavity areinsulated thermally (adiabatic). The

fluid near the hot wall rises upwards

as its density decreases by increased

temperature. Similarly, the fluid

near the cold wall falls down as

density decreases by reduced

temperature. The driving force of 

the clockwise motion in the cavity is

thermal effects (Buoyancy).

  Viscosity μ=  0.000001 kg/ms

  Density ρ=1 kg/m3. 

  TREF = (TH + TC) / 2 ⇒ (365 + 335) / 2 = 350 K

  Area = 0.0064 m2 

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 Figure 1. Case A_Scaled Residuals

Figure 2. Drag History

Figure 3. Case A_Ux

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 Figure 4. Case A_Uy

Figure 5. Case B_Scaled Residuals

Figure 6. Case B_Heat Flux on Wall Left

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 Figure 7. Case B_Heat Flux on Wall Right

Figure 8. Case B_Static Temperature

Figure 9. Case B_Ux

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 Figure 10. Case B_Uy

Calculations

Case A

() ⇒

where V  is velocity,  L is length,  ρ is density and  μ is dynamic viscosity. Re is equals to320 smaller than critical value 5000, and therefore the flow is laminar.

Case B

() ( )

()

⇒

⁄

 

where g is gravitational acceleration, β=1/ TREF and TREF is the reference temperature. Gris equals to 430518857 smaller than critical value 10

9and therefore the flow is laminar.