Project: Pulse Two - Performance of a Hydraulic Free Piston Engine
Contact: Professor Martti Larmi
Tel. +358-9-451 3459
The main project, Pulse
2001, is carried out in co-operation with Tampere University of Technology, Institute of Hydraulics and Automation
(TUT/IHA) and some companies, whose
products has similar features than free piston engine. The project
Pulse Two is a subproject of Pulse 2001 and is carried out at the
The basic research phase, which was mainly funded by TEKES (Finnish National Technology
Agency), started in the beginning of the year 1997 and was
finished at the end of the 1999. The goal of this stage was to develop
peripheral technologies, which are used in the hydraulic free piston
engines, and to create solid base for the future studies. Such
technologies are combustion, fuel injection, control, measuring and
hydraulics. During the two year phase basic analysis of the concept
and basic simulations was carried out, also experimental tests in the
field of sensor, valve and pump technology was done. In addition to
this the first prototype engine was designed and built.
The project is in its second phase. The objective of this phase is
to find out the dependence of the performance characteristics and
applicability of the hydraulic free piston engine on the design and
operation parameters. The study has great novelty value because such
studies concerning the behaviour of the performance characteristics of
the hydraulic free piston engine in different operation points has not
been reported before.
The research methods are analytical studies, computer simulation
and experimental tests with prototype engine. Simulations are
performed with different kind of simulation software. Experimental
tests with prototype engines are used to verify the simulations.
During the second phase of the project a new prototype engine will be
designed and built.
About the Free Piston Engine
The free piston engine is so called dual piston hydraulic free
piston engine. The engine has two combustion cylinders at both ends of
the engine and the hydraulic pump is located in the middle. The
combustion engine is two-stroke diesel engine with direct fuel
injection. The hydraulic pump is a constant displacement plunger
pump. The power level is around 20 kW. The studied dual piston design
is based on the patents, which are property of Sampower Ltd., which
main shareholder is SITRA (Finnish
National Fund for Research and Development).