Forced Convection during external flow over Plates

What is the definition of free convection?

• Convection due to fans
• Convection due to pump
• Convection due to gravity
• Convection due to wind

Which type of flow is responsible for boundary layer formation in forced convection?

• Turbulent flow
• Laminar flow
• Both laminar and turbulent flow
• None of the above

What is the effect of increasing the flow velocity on the thickness of the boundary layer?

• Increases
• Decreases
• Remains the same
• None of the above

What is the critical Reynolds number for transition from laminar to turbulent flow over a flat plate?

• 1000
• 2000
• 5000
• 10000

In forced convection over a flat plate, the velocity distribution across the boundary layer is best described as:

• Linear
• Parabolic
• Uniform
• Exponential

In free convection over a vertical plate, the boundary layer thickness at the leading edge is:

• Very thin
• Very thick
• Same as the boundary layer thickness at the end of the plate
• None of the above

Which of the following factors affect the Nusselt number in forced convection over a flat plate?

• Reynolds number and Prandtl number
• Grashof number and Reynolds number
• Grashof number and Prandtl number
• Reynolds number, Grashof number and Prandtl number

Which of the following is NOT an assumption in the derivation of the boundary layer equations for forced convection?

• Steady state
• Incompressible flow
• Constant density
• Constant velocity

Which of the following is a characteristic of turbulent flow in free convection over a vertical plate?

• High heat transfer rate
• Smooth flow
• Ordered flow
• Low heat transfer rate