To improve the performance and durability of two-stroke engines,
temperature of the liner/block is an important parameter, which
needs to be optimized. In this paper, an attempt is made to measure
and investigate the maximum liner temperature of a
forced-air-cooled two-stroke engine.
The vehicle was tested on both chassis dynamometer and test
track to identify the maximum liner temperature during operating
conditions. Thermocouple locations were selected at or near the hot
spots (TDC & Exhaust port) in the cylinder block. The chassis
dynamometer test revealed that the maximum liner temperatures for
the test vehicle were near the exhaust port reference position (34
mm from the top face of cylinder block) and TDC reference position
(8 mm from the top face of cylinder block near the exhaust port).
The Computational Fluid Dynamics (CFD) simulation was used to study
the flow pattern around the block and the results revealed that
design modifications can be done on the base cowl to improve and
optimize the cylinder block liner temperature. Hence, the base cowl
was experimentally modified using prototype cowls and was tested on
chassis dynamometer to verify the temperature reduction.
The target of reducing the maximum liner temperature for the
test engine below the critical value (240°C) was achieved using the
finalized experimental prototype cowl. Confirmation trials on the
test track for the finalized prototype cowl demonstrated that there
was a temperature reduction of 9% at exhaust reference position and
5% at TDC reference position.