A centrifugal compressor having a casing that houses an impeller allowing rotation about a rotational axis C, a gas channel, a treatment hollow part provided inside the casing, a first channel open to the gas channel on the downstream side of the blade leading edge of the impeller, a second channel open to the gas channel at the upstream side of the blade leading edge, a guide vane that imparts a swirl component in an opposite rotational direction of the impeller to gas discharged from the second channel, a constricting part that constricts the gas channel, and a rectifying part that rectifies gas in a direction that minimizes the swirl component about the rotational axis C and also increases the component in the direction of the rotational axis C.

A method for propulsion of a vehicle (100): The vehicle (100) includes a combustion engine (101), and a gearbox (103) that can be adjusted to a number of gear ratios for transfer of force between the combustion engine (101) and at least one driving wheel (113, 114), at least one combustion chamber with at least one inlet for the supply of combustion gas and at least one outlet for the evacuation of an exhaust gas flow that has resulted from combustion in the combustion chambers and a turbocharger unit (203) for pressurizing the combustion gas. In the method, during the change of gear from a first higher gear ratio to a second lower gear ratio, the rate of revolution of the combustion engine (101) is reduced, to control the turbocharger unit such that the pressure of the combustion gas is reduced, to increase the pressure at the outlet by constriction of the exhaust gas flow, and when the rate of revolution of the combustion engine (101) has at least partially fallen towards a second rate of revolution, to control the turbocharger unit such that the combustion gas pressure is increased. Also a system and a vehicle including the system.

A method for propulsion of a vehicle (100): The vehicle (100) includes a combustion engine (101), and a gearbox (103) that can be adjusted to a number of gear ratios for transfer of force between the combustion engine (101) and at least one driving wheel (113, 114), at least one combustion chamber with at least one inlet for the supply of combustion gas and at least one outlet for the evacuation of an exhaust gas flow that has resulted from combustion in the combustion chambers and a turbocharger unit (203) for pressurizing the combustion gas. In the method, during the change of gear from a first higher gear ratio to a second lower gear ratio, the rate of revolution of the combustion engine (101) is reduced, to control the turbocharger unit such that the pressure of the combustion gas is reduced, to increase the pressure at the outlet by constriction of the exhaust gas flow, and when the rate of revolution of the combustion engine (101) has at least partially fallen towards a second rate of revolution, to control the turbocharger unit such that the combustion gas pressure is increased. Also a system and a vehicle including the system.

A catalytic converter device for a stationary internal combustion engine includes at least one bracket for mounting the catalytic converter device on a carrier, and at least one catalyst substrate which can be releasably arranged in a housing of the catalytic converter device, the catalyst substrate having a cell density of at least 50 cpsi, preferably greater than 100 cpsi.

A catalytic converter device for a stationary internal combustion engine includes at least one bracket for mounting the catalytic converter device on a carrier, and at least one catalyst substrate which can be releasably arranged in a housing of the catalytic converter device, the catalyst substrate having a cell density of at least 50 cpsi, preferably greater than 100 cpsi.

An impeller (60) for use in a supercharger (42), which is cable of increasing the efficiency while suppressing the increase in size of the impeller (60), is driven in driving connection with a crankshaft (26) of a combustion engine (E) mounted on a motorcycle to supply an intake air (I) towards the combustion engine (E). When the supercharger (42) is driven at a maximum permissible engine speed of an inlet diameter (Ii), the impeller (60) is so set that the peripheral velocity at an inlet side tip end portion (112) of the impeller (60) may exceed the sonic velocity, and may be smaller than 1.3 times the sonic velocity.

An impeller (60) for use in a supercharger (42), which is cable of increasing the efficiency while suppressing the increase in size of the impeller (60), is driven in driving connection with a crankshaft (26) of a combustion engine (E) mounted on a motorcycle to supply an intake air (I) towards the combustion engine (E). When the supercharger (42) is driven at a maximum permissible engine speed of an inlet diameter (Ii), the impeller (60) is so set that the peripheral velocity at an inlet side tip end portion (112) of the impeller (60) may exceed the sonic velocity, and may be smaller than 1.3 times the sonic velocity.

A centrifugal compressor includes: an impeller (compressor impeller); a main flow passage, which has the impeller arranged therein, and extends in a rotation axis direction of the impeller; an auxiliary flow passage formed on a radially outer side of the impeller with respect to the main flow passage; an upstream communication passage configured to allow the auxiliary flow passage and the main flow passage to communicate to each other; a downstream communication passage configured to allow the auxiliary flow passage and the main flow passage to communicate to each other on a side closer to the impeller with respect to the upstream communication passage; and a partition portion (rib or fin) configured to partition the auxiliary passage in a circumferential direction while maintaining a gap larger than a flow passage width of the downstream communication passage in the auxiliary flow passage.

A centrifugal compressor includes: an impeller (compressor impeller); a main flow passage, which has the impeller arranged therein, and extends in a rotation axis direction of the impeller; an auxiliary flow passage formed on a radially outer side of the impeller with respect to the main flow passage; an upstream communication passage configured to allow the auxiliary flow passage and the main flow passage to communicate to each other; a downstream communication passage configured to allow the auxiliary flow passage and the main flow passage to communicate to each other on a side closer to the impeller with respect to the upstream communication passage; and a partition portion (rib or fin) configured to partition the auxiliary passage in a circumferential direction while maintaining a gap larger than a flow passage width of the downstream communication passage in the auxiliary flow passage.

Starting an internal combustion engine may be difficult as a consequence of the operating conditions of the engine. Even after the engine has started, it may take a long period of time for the engine to reach operating temperatures. In the present disclosure, when engine start difficulty is expected, before starting the engine a forced induction compressor arranged with the engine may be turned on to increase the engine intake air pressure before the engine is started.