Convection experiment
Sponsored Links
This presentation is the property of its rightful owner.
1 / 19

Convection Experiment PowerPoint PPT Presentation


  • 146 Views
  • Uploaded on
  • Presentation posted in: General

Convection Experiment. Leader: Tom Salerno Partners: Greg Rothsching Stephen Johnson Jen DiRocco. What will you hear today?. Introduction Theory Equipment and Procedure Results and Discussion Conclusions Questions. Introduction. What is convection?

Download Presentation

Convection Experiment

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Convection Experiment

Leader: Tom Salerno

Partners:

Greg Rothsching

Stephen Johnson

Jen DiRocco


What will you hear today?

  • Introduction

  • Theory

  • Equipment and Procedure

  • Results and Discussion

  • Conclusions

  • Questions


Introduction

  • What is convection?

    • Heat transfer from fluid flowing over solid surface

  • Why study convection?

    • Occurs in almost every process plant

    • Example: Heat Exchangers, Tray Dryers, etc.


Theory – Newton’s Law of Cooling

  • Flat Plate:

  • Finned Plate (Resistances in Parallel):


Theory – Forced Convection

  • Physical Situation:

  • Solving Boundary Layer Equations

    • Continuity Equation -

    • Momentum Balance -

    • Thermal Balance –

    • Rigorous analytical solution


Theory – Forced Convection

  • Forced Convection – analytically developed

    • Dimensionless Parameters

      • Reynolds:

      • Prandtl:

      • Nusselt:

    • Flat Plate:


Theory - Natural Convection

  • Physical Situation:

    • New Momentum Equation:

      • Must now solve all three boundary layer equations simultaneously


Theory - Natural Convection

  • Experimental Correlation:

    • Churchill and Chu

    • Dimensionless Parameters

      • Grashoff:

      • Rayleigh:

    • Correlation:


Equipment and Procedure

Figure 9: Front view of convection duct.

Figure 10: Side view of convection duct.


Results and Discussions

  • Flat Plate: Laminar Flow


Results and Discussions

  • Turbulent Mix

    • New Correlation -


Results and Discussions

  • Flat Plate: Turbulent Mix


Results and Discussions

  • Finned Plate: Laminar


Results and Discussions

  • Turbulent Mix

    • New Correlation -


Results and Discussions

  • Finned Plate: Turbulent Mix


Results and Discussions

  • Effectiveness of Fin Addition


Conclusions – What we learned

  • The convective heat transfer coefficient increases linearly with the square root of air velocity

  • Predictive Equations are useful for predicting trend in data, but not the absolute numbers

  • Natural Convection is the limit to forced convection, though it is difficult to predict

  • The addition of fins will increase the heat transfer rate substantially at low air velocities, but not as much at higher air velocities


Conclusions – Significance?

  • Aid in design of heat exchangers

    • How to increase heat transfer coefficient

    • How to increase heat transfer rate

    • Realize presence of natural convection for cheap ways to cool electronic equipment

  • Confidence of Predictive Equations

    • Use for other experiments, such as tray dryer

    • Only if can perfectly match geometry, or can run a short scale experiment to obtain correction factor


Questions?


  • Login