• PhD,

PhD defense: Hanna SARA - ED SPIGA

"Study and valorisation of new thermal management systems of an automotive powertrain"

On September 20, 2017 from 14:00 To 23:59

Wednesday, September 20, 2017 at 2 pm in Lecture Theatre B9, Centrale Nantes

Supervisor: David CHALET

Laboratory: LHEEA


Thermal management proved itself in improving the fuel efficiency of the engine. Nowadays, automotive companies tend to apply different strategies to answer the greenhouse severe laws. The PhD aim is to valorize and analyze the different thermal management strategies with numerical simulations over different driving cycles and ambient conditions.

A 1-D simulation code of the engine and its hydraulic circuits were built using GT-Suite. Four known driving cycles were chosen: NEDC, WLTC, AH and AU. In addition, an in-house developed driving cycle was introduced. An energy balance made over the different stages of the driving cycles underlines the importance of the heat storage and the exhaust heat recovery strategies.

Heat recovery was applied over the coolant and the oil at ambient temperatures of -7°C and 20°C. Hot coolant storage and hot oil storage led to improve the coolant and lubricant initial temperatures respectively. Different configurations (total of 7) were proposed and studied. A multifunctional oil sump was introduced. Important fuel consumption savings were obtained.

Exhaust heat recovery was then valorized. Heat exchanger was characterized over experimental setup then added to the engine model. Indirect and direct heating of the lubricant as well as both strategies back to back were tested. Remarkable friction reduction and fuel savings were obtained. Special configuration was proposed to control the lubricant high temperature instead of the bypass on the exhaust line.

The study ended by valorizing minor strategies as the oil’s grade influence, the engine insulation, high temperature set point …

Publié le September 12, 2017 Mis à jour le September 22, 2017