Abstract: A centrifugal compressor includes: a volute casing including a first casing and a second casing that are mutually coupled, the first casing including a volute chamber therein and the second casing including an impeller installation space therein; an impeller provided in the impeller installation space so as to be rotatable around a rotation axis; and a vaneless diffuser that has an inlet that communicates with an inside of the second casing and has an outlet that communicates with an inside of the first casing. The vaneless diffuser has a width having a non-axisymmetric distribution in the circumferential direction.

Abstract: A turbo-compound apparatus having a variable geometry turbocharger turbine and an engine system having the same are provided. The turbo-compound apparatus includes a variable geometry turbocharger turbine connected to an exhaust manifold of the engine and having an adjustable mechanism to distribute the exhaust energy between two turbines; a power turbine fitted downstream of the variable geometry turbocharger turbine and driven by exhaust gas passing through the variable geometry turbocharger turbine, an output end of the power turbine being adapted to connect with a crankshaft of the engine to transfer mechanical work output from the power turbine to the crankshaft; and an actuator configured to control the adjustable mechanism according to actual engine operation conditions to regulate the exhaust energy distribution between the variable geometry turbocharger turbine and the power turbine.

Abstract: A centrifugal compressor includes: a volute casing including a first casing and a second casing that are mutually coupled, the first casing including a volute chamber therein and the second casing including an impeller installation space therein; an impeller provided in the impeller installation space so as to be rotatable around a rotation axis; and a vaneless diffuser that has an inlet that communicates with an inside of the second casing and has an outlet that communicates with an inside of the first casing. The vaneless diffuser has a width having a non-axisymmetric distribution in the circumferential direction.