Researchers at the NASA Langley Research Center (LaRC) are developing a next-generation instrument for monitoring the Earth radiation budget (ERB) from low Earth orbit. This instrument is called the DEMonstrating the Emerging Technology for measuring the Earth's Radiation (DEMETER) instrument. DEMETER is a candidate to replace the Clouds and Earth's Radiant Energy System (CERES) instruments which currently monitor the ERB. LaRC has partnered with the Thermal Radiation Group at Virginia Tech to model and evaluate the thermal and optical design of the DEMETER instrument. The effort reported here deals with the numerical modeling of the optical and thermal radiative performance the DEMETER instrument. The numerical model is based on the Monte Carlo Ray-Trace (MCRT) method. The major optical components of the instrument are incorporated into the ray-trace model using 3-D surface equations. A CAD model of the instrument baffle is imported directly into the ray-trace environment using an STL triangular mesh. The instrument uses a single freeform mirror to focus radiation on the detector. A method for incorporating freeform surfaces into a ray-trace model is described. The development and capabilities of the model are reported. The model is used to run several ray-traces to compare two different quasi-black surface coatings for the DEMETER telescope baffle. Included is a list of future tests the Thermal Radiation Group will use the model to accomplish. / Master of Science / For decades NASA has used satellite-mounted scientific instruments to monitor the Earth radiation budget (ERB). The ERB is the energy balance of the planet Earth with its surroundings. Radiation from the sun is absorbed and reflected by the Earth. The Earth also emits radiation. The balance between these heat transfer components drives the planetary climate. Researchers at the NASA Langley Research Center (LaRC) are developing a new instrument for monitoring the ERB from low Earth orbit. This Earth observing instrument is called the DEMonstrating the Emerging Technology for measuring the Earth's Radiation (DEMETER) instrument. NASA has partnered with the Thermal Radiation Group at Virginia Tech to model and evaluate the thermal and optical design of the DEMETER instrument. The effort reported here deals with the numerical modeling of radiation heat transfer in the DEMETER instrument. The numerical model uses the Monte Carlo Ray-Trace (MCRT) method to evaluate the thermal and optical behavior of the DEMETER instrument. The development and capabilities of the model are reported. The model is used to run a series of simulations to compare the performance of two different quasi-black surface coatings for the DEMETER telescope baffle. Included is a list of future tasks the Thermal Radiation Group will accomplish using the model.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/112752 |
| Date | 08 June 2021 |
| Creators | Fronk, Joel Seth |
| Contributors | Mechanical Engineering, Mahan, James R., Nguyen, Vinh, Vick, Brian |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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