The objectives of most fluorescent lighting applications include the following:
- To the determine if the environment temperature surrounding the fixture exceeds known limits.
- To ensure the heat dissipated from the lamp does not overheat the socket and ballast.
Modeling Guidelines
- Simplify the socket geometry in the CAD model.
- Model the fixture either in an installed configuration or within a test environment.
- To model the fixture as installed, use the appropriate modeling strategy.
- If the fixture is very close to the ceiling, and air cannot physically flow upward from the mounting box, it may be necessary to close the top boundary:
- Assign the ambient temperature and pressure = 0 only to the bottom surface.
- Do not assign a pressure boundary condition to the top surface.
- To model the fixture in a test environment, use the Test box configuration.
- Include the glass tube in the geometric model, and use its physical thickness.
Material Considerations
- Assign a solid material to the gas inside the tube. Specify the conductivity to be that of the gas inside the tube.
Heat Loading
- The fluorescent input power is the product of Voltage and current. Typically, 15-35% of the input power is dissipated as heat (the rest is light).
- Apply a heat generation boundary condition to the gas "solid" within the tube that is between 15 and 35% of the power supplied to the fluorescent tube.
LED |Unit 3