Diffuser (thermodynamics)

About: Diffuser (thermodynamics) is a research topic. Over the lifetime, 6731 publications have been published within this topic receiving 54738 citations.

An inverse design method of diffuser blades by genetic algorithms

Abstract: A genetic algorithm incorporating a neural network technique is proposed to search for a turbomachinery diffuser blade profile that produces a given velocity distribution on its surface. Such a new inverse design method works through minimizing the error between the surface velocity distribution of candidate blades and the target velocity distribution. For ease of employing the genetic algorithm, the blade profiles to be searched are parameterized by Bezier curves. To fix the surface velocity distribution of a candidate blade, a special type of back propagation (BP) neural network is implemented. The proposed approach is illustrated by a diffuser having two-dimensional blades with constant height and thickness. The simulations show that the new method is not only feasible but also reliable and efficient.

Experimental Results on a Rotatable Low Solidity Vaned Diffuser

Abstract: This paper reviews test results from a rotatable low solidity vaned diffuser (RLSD). The device was installed in a single stage test vehicle consisting of a pseudo-return channel inlet, a subsonic centrifugal impeller (approx. 2:1 pressure ratio), the rotatable diffuser, a return channel and a dump collector. Static taps, total pressure probes, and thermocouples were located in critical areas throughout the stage. Manual traverse probes measured the pressure and angle profiles at RLSD leading and trailing edges. Results for various stagger angles, leading edge radius ratios, etc. are presented in terms of pressure recovery (Cp) and loss coefficient (LC). Comments are made regarding the applicability of the RLSD in production units.Copyright © 1992 by ASME

Tubular embedded nozzle assembly for controlling the flow rate of fluids downhole

Abstract: An apparatus (100) for controlling the flow rate of a fluid during downhole operations. The apparatus (100) includes a tubular member (134) having a flow path (136) between inner and outer portions of the tubular member (134). The flow path (136) includes an inlet (138) in an inner sidewall (140) and an outlet (142) in an outer sidewall (144) of the tubular member (134). The inlet (138) and the outlet (142) are laterally offset from each other. A fluidic device (146) is positioned in the flow path (136) between the inlet (138) and the outlet (142). The fluidic device (146) is embedded within the tubular member (134) between the inner sidewall (140) and the outer sidewall (144). The fluidic device (146) includes a nozzle (154) having a throat portion (156) and a diffuser portion (158) such that fluid will flow through the nozzle (154) at a critical flow rate.

Large volume beverage dispensing nozzle

Abstract: A beverage dispensing nozzle (10) which dispenses beverages at a high volume flow comprises a housing (11) which includes a body (52) and a cap (14) having an opening therein connected to the top of the body (52), a conduit (12) in the lower portion of the body (52), a diffuser (13) residing over the conduit (12), and a diffuser plate (44) positioned about the diffuser (13) The nozzle (10) connects to a standard electric valve which communicates with both a beverage syrup source and a mixing fluid source The diffuser (13) includes a passageway (27) which communicates with the beverage syrup source to deliver beverage syrup to a mixing chamber (51) The exterior body of the diffuser (13) and the interior surface of the body define a second channel (48) The diffuser plate (44) resides within the first channel (29) and includes a plurality of holes that produce a laminar flow in the mixing fluid stream as it enters the first channel (29) Upon exit from the first channel (29), the conduit (12) divides the mixing fluid stream into a first and second mixing fluid streams

The effect of the microfluidic diodicity on the efficiency of valve-less rectification micropumps using Lattice Boltzmann Method

Abstract: The efficiency of the valve-less rectification micropump depends primarily on the microfluidic diodicity (the ratio of the backward pressure drop to the forward pressure drop). In this study, different rectifying structures, including the conventional structures (nozzle/diffuser and Tesla structures), were investigated at very low Reynolds numbers (between 0.2 and 60). The rectifying structures were characterized with respect to their design, and a numerical approach was illustrated to calculate the diodicity for the rectifying structures. In this study, the microfluidic diodicity was evaluated numerically for different rectifying structures including half circle, semicircle, heart, triangle, bifurcation, nozzle/diffuser, and Tesla structures. The Lattice Boltzmann Method (LBM) was utilized as a numerical method to simulate the fluid flow in the microscale. The results suggest that at very low Reynolds number flow, rectification and multifunction micropumping may be achievable by using a number of the presented structures. The results for the conventional structures agree with the reported results.