Abstract An efficient biomass pyrolysis process requires a comprehensive understanding of the chemical and physical phenomena that occur at multi‐length time scales. In this study, multiscale computational approach was developed validated for in packed‐bed reactor by integrating kinetics, particle scale model, Superquadric Discrete Element Method‐Computational Fluid Dynamics (SuperDEM‐CFD) open‐source code MFiX. A one‐dimensional particle–scale model discretizes characteristic length into...

The mechanical shear degradation of polydisperse polyisobutene and monodisperse polystrene in oils different viscosities the concentration range 0.1% to 1% was studied using a high-shear concentric cylinder viscometer under laminar uniform well-defined field conditions. Molecular weight distributions (MWDs) were measured by gel permeation chromatography (GPC). Degradation solutions narrows principally through breaking down large molecules. polystyrene broadens at lower stress. At higher...

Abstract Fluidization behavior of biomass and glass beads binary mixtures in a bubbling fluidized bed was experimentally investigated. Mixtures containing different mass fraction Loblolly Pine white wood were at fluidization velocities. The particle properties characterized QICPIC that uses dynamic image processing method to measure both size sphericity. minimum velocity determined using the pressure drop method. An developed capture expanded height very high frequency. effect inlet gas on...

Abstract Biomass gasification is widely recognized as an effective method to obtain renewable energy. To accurately predict the syngas and tar compositions a challenge. A chemical reaction kinetics model based on comprehensive proposed simulate downdraft biomass gasification. The kinetic validated by direct comparison experimental results of two gasifiers available in literature found be more accurate than used Gibbs energy‐minimizing (GEM model). then applied investigate effects equivalence...

Abstract This article investigated the fluidization of sands and small Geldart A biomass mixtures. The mixture fluidized like type particles with a uniform bed expansion regime before bubbling. video recorded color distance between pure sands–biomass mixtures was used to estimate mixing. coarse‐grained computational fluid dynamics–discrete element method hybrid drag model which couples Syamlal–O'Brien filtered can capture mixing while simulation Gidaspow predicted segregated bed. simulations...

Abstract High fidelity three‐dimensional (3‐D) numerical simulations of commercial‐scale coal gasifiers are very time consuming and expensive. This article proposes a reduced‐order modeling approach that uses quasi one‐dimensional (1‐D) CFD–DEM simulation results to serve as an accurate initial condition for the 3‐D simulation, which significantly shortens physical from several hours minutes achieve steady states. The employs previously validated coarse‐grained CFD‐DEM approach, further...

Rotating drum experiments on binary mixtures of plastic spheres with wood spheres, cylinders, and cubes were investigated, respectively. A high-resolution camera was employed to record the flow behaviors mixtures. machine learning-assisted image processing method developed segment particles different shapes, its superiority demonstrated by comparing results pixel artificial counting methods. This used analyze images recorded from mixture explore effects rotating speed, particle shape,...

This paper describes the collaborative work performed by Goodrich and Boeing to design, build demonstrate flight benefit of a one-piece, acoustically smooth engine intake liner. The is done under joint Quiet Technology Demonstrator 2 (QTD2) program between Boeing, ANA, GE, Goodrich, NASA. focus describe acoustic features inlet, show how these were designed, give details on realized benefits. design includes three that enhance its performance. These are an inlet liner with area maximization,...

Industrial-scale gasifiers are traditionally designed using performance data from small-scale systems and expert experiences. In this research, the computational fluid dynamics (CFD)-coarse-grained discrete element method (CGDEM) model in open-source software MFiX was employed to assist design of a 22 MW updraft moving-bed coal gasifier. A quasi-one-dimensional CFD-DEM simulation first performed; its results were then served as an accurate initial condition for three-dimensional (3D)...

Fluidized beds are usually used in the thermochemical conversion of waste plastic due to their excellent efficiency. The complex fluidization behaviors sand–plastic binary mixtures not fully understood. multiphase particle-in-cell (MP-PIC) model was employed and validated this study investigate hydrodynamics. MP-PIC adopts a coarse-grained approach by lumping certain number particles into parcel uses solid stress instead resolving direct particle contacts. effects key settings parameters...

The ability to design, build, and test miniaturized acoustic treatment panels on scale model fan rigs representative of the full-scale engine provides not only a cost-saving but an opportunity optimize by allowing tests different designs. To be able use as design tool, it is necessary that designer reliably translate performance equivalent design. key this accomplishment impedance parameter. Current models for have been validated measurement up about 6000 Hz. It purpose study examine...

A low resistance, large POA (percentage open area) perforate skin (greater than 20 POA) and a deep cavity (deeper 10 inches to attain the acoustic reactance values that slightly exceeds zero at 500 Hz) Helmholtz resonator is required suppress combustion noise in frequency range from 400 Hz during an aircraft approach (landing) condition. However, due space limitations area of center plug, it impossible design conventional with sufficient depth reduce 400-500 noise. In this study,...

Aircraft noise has become an increasing concern for commercial airlines. Worldwide demand quieter aircraft is increasing, making the prediction of engine suppression one most important fields research. The Low-Pressure Turbine (LPT) can be source during approach condition aircraft. National Aeronautics and Space Administration (NASA), Pratt & Whitney (P&W), Goodrich Aerostructures (Goodrich) conducted a joint program to validate method predicting turbine attenuation. includes noise-source...

This study demonstrates by experiment that naturally aspirated bias flow can be used to control liner impedance and alter acoustic attenuation. Two controlled adaptive samples were fabricated BFGAIAG, one for normal incidence measurement, the other insertion loss measurement with/without (blowing suction). Normal measurements of two conducted .both with without flow. The test results are presented in this paper. University Colorado performed analysis behavior concept, their findings will...

Two-stage anaerobic reactors are being widely used in the organic waste management industry. In these reactors, up to one-third of chemical oxygen demand (COD) content is naturally pre-acidified a first stage pre-acidification (PA) and then fed second digester for conversion methane. Traditionally, all generated gases from PA tank will be vented atmosphere. Hydrogen carbon dioxide main tank. A pilot-scale two-stage expanded granular sludge bed reactor was fabricated investigate impact gas...