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Today the environmental issues are a lot on the agenda and the environmental awareness are more and more common. New laws and restrictions on engines emissions are enforced and the demand on the engines gets higher and tougher. This leads to the engine testing playing a more crucial part than ever. Engine tests are done using an engine dynamometer. The dynamometer loads the engine by, in many different ways, absorbing the power and torque generated by engine. The most important functions of a dyno are to convey the power from the engine to the dyno, to load the engine, to measure the power and torque generated by the engine and to remove the excess heat that is generated. Husqvarna is a Swedish company that produces garden and forest cutting tools, their most famous products are their chainsaws. Husqvarna does an extensive amount of engine testing, long time testing, functional testing and field testing. Some functional tests, such as start-ability after use is done in a climate chamber where the humidity and temperature can be set. Today, loading a chainsaw in -25 °C is a problem due to the fact that the most used dynamometer at Husqvarna is a water brake that freezes in minus degrees. This master thesis will answer the question on how to, for small engine, simulate the load that occurs during normal use of the engine and how to develop a dynamometer suitable for Husqvarna’s needs? The focus when developing the dynamometer will lie on solving the problem with minus degrees and having a good detachable coupling between the dyno and the chainsaw. The result is a hydraulic oil dynamometer. A hydraulic pump is attached to the guide bar and chainsaw using a detachable key way coupling and bearings. By controlling restriction of the flow in the hydraulic system the load can be controlled and also ultimately the RPM of the chainsaw. The hydraulic oil works fine in the minus degree as long as the right oil with the right viscosity range is used although a problem with the

Today the environmental issues are a lot on the agenda and the environmental awareness are more and more common. New laws and restrictions on engines emissions are enforced and the demand on the engines gets higher and tougher. This leads to the engine testing playing a more crucial part than ever. Engine tests are done using an engine dynamometer. The dynamometer loads the engine by, in many different ways, absorbing the power and torque generated by engine. The most important functions of a dyno are to convey the power from the engine to the dyno, to load the engine, to measure the power and torque generated by the engine and to remove the excess heat that is generated. Husqvarna is a Swedish company that produces garden and forest cutting tools, their most famous products are their chainsaws. Husqvarna does an extensive amount of engine testing, long time testing, functional testing and field testing. Some functional tests, such as start-ability after use is done in a climate chamber where the humidity and temperature can be set. Today, loading a chainsaw in -25 °C is a problem due to the fact that the most used dynamometer at Husqvarna is a water brake that freezes in minus degrees. This master thesis will answer the question on how to, for small engine, simulate the load that occurs during normal use of the engine and how to develop a dynamometer suitable for Husqvarna’s needs? The focus when developing the dynamometer will lie on solving the problem with minus degrees and having a good detachable coupling between the dyno and the chainsaw. The result is a hydraulic oil dynamometer. A hydraulic pump is attached to the guide bar and chainsaw using a detachable key way coupling and bearings. By controlling restriction of the flow in the hydraulic system the load can be controlled and also ultimately the RPM of the chainsaw. The hydraulic oil works fine in the minus degree as long as the right oil with the right viscosity range is used although a problem with the

"Report developed under STTR contract W911NF-08-C-0107" for topic "A08-T012". The overall objective of this STTR project is to develop electrostatic atomizers for spraying JP-8 fuel in small scale internal combustion engines. This report discusses the efforts of Phase I where it has been demonstrated that the proposed charge injection method can be used for atomization of JP-8. The characteristics of sprays formed with JP-8 are found to be very similar to those of sprays formed with diesel fuel using the same method of atomization, regardless of a difference in electrical conductivity coefficients of these fuels. This important finding allows us to use the extensive previous knowledge on diesel fuel to understand the atomization of JP-8. The above demonstration of JP-8 atomization was based on an existing point-blade charge injector. Further investigation has been conducted in Phase I to improve this design in order to achieve higher specific charges and higher fuel flow rates. One design of the new atomizer was successfully tested and the data presented in this report support the improvement of the spray characteristics. Finally, new concepts have been investigated to apply the method of charge injection in conjunction with a pulse fuel delivery system which is required for internal combustion engines.