Research Information System
Thesis Type: Doctorate
Institution Of The Thesis: Bursa Uludağ University, FEN BİLİMLERİ ENSTİTÜSÜ, Mechanical Engineering, Turkey
Approval Date: 2020
Thesis Language: Turkish
Student: MEHMET AKTAŞ
Supervisor: Muhsin Kılıç
Abstract:Today, automotive lighting products which has light emitting diodes with many advantages such as light output quality, aesthetic design, low power consumption have begun to be widely used in new cars. Unless effective thermal management is performed in LED (Light Emitted Diode) chips, which reveal the electrical energy passing through it as 70-80 % of heat, it creates problems such as poor quality and low light output and short life. Traditional cooling methods are insufficient in solving heating problems with increasing LED powers. Additionally, in the application of automotive lighting systems to the vehicle, there are problems such as limited body volume, insufficient volume for cooling units, weight limitations for product and lack of homogeneous cooling. Liquid cooled systems with high cooling capacity, not being affected by environmental conditions and stable structure allows homogeneous cooling for LED systems. Because of these advantages, hydraulic and thermal performances of liquid cooled block applications were investigated in the cooling of LED automotive lighting components within the scope of this thesis. Within the scope of the research studies, original LED printed circuit boards that can be used in front lighting products have been designed and prototypes have been manufactured. It is aimed to cool the designed and manufactured circuit boards with liquid cooled block designs. While it is desired to have a high thermal performance and homogeneous cooling in liquid cooled blocks, optimization work is required in the design to provide minimum pump power and pressure drop within the block. For this reason, computational fluid dynamics (CFD) analyzes were performed to improve cooling performance and to minimize pressure drop in block flow by working with different block structure, LED power and fluid flow values. The prototype of two block structures with minimum in block flow pressure drop, providing homogeneous cooling and the best heat transfer was manufactured and cooling of the LED printed circuit board was experimentally examined. Designed and produced LED printed circuit board and optimized block structure were placed in the front lighting assembly which is already in mass production and CFD analyzes were conducted and examined experimentally. The cooling performances and light output of the liquid cooled automotive lighting component and the automotive lighting product in mass production with traditional cooling were compared.