The hydrodynamic description of trickle flow is a complex field of study. One of the main contributors to the complexity is the existence of multiple hydrodynamic states (MHS). As early as 1978, Kan & Greenfield reported different pressure drop and holdup readings for the same liquid and gas feed rates. The study revealed that the flow history experienced by the bed determined the specific hydr...

the monolithic catalytic converter is still the main pollution control device for modern vehicles in order to reach the ever-increasing legislative demands for low emission standards. the catalytic converters require a large expansion from the exhaust pipe to the front face of the monolith. unfortunately, packaging constraints often do not permit the use of long diffusers. hence, flow separatio...

in this work, the feasibility study for design of a laboratory sample rde which has an annular geometry with diameter of 76 mm and length of 101 mm has been performed. detonation engines are expected to be used as propulsion system in aerospace applications in the future. several types of detonation engines are currently under examination, including the rotating detonation engine (rde). first, ...

one of the most problems that limits use of turbomachines at high speed applications is cavitation. cavitation can damage casing and blades of turbopump, also can make unstability in system. inducer that was installed in front of main impeller can improve cavitation characteristic of system and increase static pressure just before entrance of centrifugal pump. specially in fuel feed system of l...

sometimes the need for non-circular ducts arises in many heat transfer applications because of lower pressure drop of non-circular cross section such as square duct compared to circular tube, particularly in compact heat. but square cross section has poor heat transfer performance and it is expected that using a nanofluid as a new heat transfer media may improve the heat transfer performance of...

Emission regulations for diesel engines are being strengthened and it is impossible to meet the standards without exhaust after-treatment systems. Lack of the space in many diesel vehicles, however, make it difficult to design and install stand-alone catalytic converters such as DOC, DPF, and SCR in the vehicle exhaust systems. Accordingly, those have been installed inside the muffler to save t...

there are several sources for pressure oscillations in solid propellant rocket motors. oscillatory flow field is one of them. free shear layers in motor flow field cause vortex shedding. end edges of propellant grains and baffle edge in two-segmented motors are samples of such zones. these vortices move from their forming points and strike the field walls. the kinetic energy of vortices change ...