Minimum Cross Section Research Articles

Back to Bernoulli: a simple formula for trans-stenotic pressure gradients and retrospective estimation of flow rates in cerebral venous disease

BackgroundVenous sinus stenosis can be associated with cerebrovascular disorders. Understanding the role of blood flow disturbances in these disorders is often hampered by the lack of patient-specific flow rates. Our...

Mechanisms of void nucleation on neat and Glass Syntactic PolyPropylene using in situ synchrotron radiation tomography

The mechanisms of void nucleation of a hollow glass syntactic foam during tensile loading were studied in depth. Flat-notched geometries, cut-out from neat and Glass Syntactic PolyPropylene (GSPP), were investigated by in situ microtomography. Notched specimens with two notch root radii, 4 mm and 0.15 mm named respectively N4 and N0.15, to set initial triaxial stress state in the minimum cross section, were observed. Tomographic data sets, with a resolution of 1.3μm, from stepwise tensile loading, at the SOLEIL synchrotron radiation facilities, were retrieved from the notched zone. In addition, they allowed gathering both the width and thickness evolution in the minimum cross section, and the notch opening displacement during the tests.In line with literature, neat PolyPropylene (PP) showed crazes concentration at the specimen core in N4 specimen, whereas, in N0.15 specimen, they were located at the notch root. In isolated Hollow Glass Microspheres (HGM), mechanisms of crazing and debonding were correspondingly highlighted in the PP matrix and at the poles of HGM. Finally, in GSPP, decohesion follows the same trend as in neat PP, i.e. at the specimen core and near the notch, respectively in N4 and in N0.15 geometry. Scenarios of void nucleation and propagation were outlined. The initiation of the brittle crack in the GSPP is mainly due to the matrix-HGM decohesion followed by the coalescence of near neighbouring caps.

A Methodology for Post-Necking Analysis in Isotropic Metals

Metallic materials are commonly characterized through tensile tests. For ductile metals, a consistent part of the test occurs after the necking onset. A first estimate of the post-necking behavior could be obtained by extrapolating the mathematical model that fits the pre-necking law. However, as well known, the accuracy of the predictions would not be guaranteed. Therefore, over the past decades many efforts have been devoted to dealing with the necking phenomenon. The most popular correction formula proposed by Bridgman is an analytical method based on the neck geometry. Despite being widely used, it may not be accurate at large strains due to the assumption of uniform distribution of the equivalent stress and equivalent strain in the specimen minimum cross-section. Starting from Bridgman’s idea and in order to overcome its limitations, the present paper develops an efficient method to calibrate the hardening law of isotropic metallic materials at large strains. The proposed method requires to record the outer contour of the necking zone during the test and to build a dataset of necking deformed shapes. Experimental quasi-static tensile tests were analyzed with the proposed approach, which appears promising when critically compared with other methods.

Out-of-Plane Design Equations for Confined Masonry Walls

Nowadays there is still a lack of requirements for the out-of-plane design of confined masonry walls. Current code requirements are mainly based on the in-plane behavior of those walls. This research is divided into two parts. In the first part, two confined walls subjected to out-of-plane uniform loads were tested in the laboratory. Confining elements with minimum cross-section dimensions and wall aspect ratios smaller than one were considered. The variable studied was the wall length. Out-of-plane load—displacement curves of walls were obtained. In the second part, two design equations were developed to determine the out-of-plane strength of confined walls. A design equation was developed to determine the corresponding in-plane forces transferred to the confining elements. The out-of-plane strength of 6912 walls was determined using a computer program based on the bidirectional strut method. A parametric analysis was carried out for the out-of-plane strength considering different variables. Multiple linear regression analyses were carried out to propose out-of-plane strength design equations. It was concluded that the experimental out-of-plane strength increased, and the wall failure type changed as the wall length decreased. In addition, the experimental out-of-plane strength of walls was well predicted with both out-of-plane design equations.

An approach to hydraulic design of Conical Central Baffle Flumes

Design methodology for providing a Conical Central Baffle flume (CCBF) has not yet been found in the literature, though it is required by the hydraulic engineers considering the increased popularity of the baffled flumes, now-a-days. Some guidance for discharge prediction using CCBF is only found in the literature. The main objective of the present research is to address the issue of hydraulic design of CCBFs. A measuring flume serves as a device for quantifying the flow rate in an open channel. These flumes operate on the basis of principles of critical flow and energy conservation. Conventionally, it is assumed that the critical flow occurs at location of the minimum flow cross-section or throat. In the current investigation, a CCBF is employed to gauge the flow discharge. The CCBF configuration involves placing one conical obstruction in a trapezoidal channel, thus creating a throat. One of the objectives of the study is to scrutinize the prevailing location of the critical section and introduce a refining approach to discharge prediction. Through a series of experiments and numerical simulations, the present study endeavors to ascertain the true location of the critical section in CCBF. Contrary to the traditional belief that the critical section is always at the throat, the investigation revealed that the critical section tends to shift upstream with increased discharge. The theoretical analysis, employing energy expression and critical flow concepts, unveiled that despite this shifting nature, the energy-critical depth ratio of the flume remains constant. Based on these findings, a discharge prediction model is proposed. The model demonstrates a mean relative error of ±1.42 % and a maximum relative error of 3.5 % in discharge prediction. The theoretical investigation also highlighted that the critical section occurring at the throat signifies the minimum discharge value, and induced a threshold choking flow condition in the flume. The present study also proposes the expressions for minimum as well as maximum discharge measuring capacity of a CCBF which leads to its proper design methodology, which has never been presented so far in the literature. Additionally, a design example is presented, elucidating the process of designing a conical CCBF for a trapezoidal channel based on the understanding of the limiting discharge.

Ultrafast laser composite cutting ultra-thin glass

Due to its excellent chemical stability, and scratch resistance, ultra-thin glass (less than 1 mm) has been widely used in the consumer electronics and photovoltaic industries. To meet the requirements of high-quality ultra-thin glass cutting, the composite cutting of ultra-thin glass based on ultrafast laser is proposed which consists of laser internal modification and surface scribing. The effects of laser pulse duration, laser pulse energy, and pulse separation rate on the laser internal modified region of ultrathin glass are studied. The cut quality of the samples under two surface groove structures is compared. The maximum edge strength of 369.07 MPa and the minimum cross-section roughness of 0.148 μm are obtained by laser composite cutting with the stamp-hole-type groove structure.

Characterization of Shrink Film Properties for Rapid Microfluidics Lab-on-Chip Fabrication.

Shrink film is a thin sheet of polystyrene plastic that shrinks to 25-40% of its original size when heated. This study investigated the shrinkage factor of the film at different temperatures and baking times to determine the optimal fabrication recipe for shrink film microfluidic device production. Additionally, this study characterized the properties of shrink film, including minimum possible feature size and cross-section geometries, using manual engraving and the CAMEO 4 automated cutting machine. The optimal shrinkage factor ranged from 1.7 to 2.9 at 150 °C and a baking time of 4 min, producing the ideal size for microfluidic device fabrication. The X- and Y-axes shrank ~2.5 times, while Z-axis thickened by a factor of ~5.8 times. This study achieved a minimum feature size of 200 microns, limited by the collapsing of channel sidewalls when shrunk, leading to blockages in the microchannel. These findings demonstrate the feasibility and versatility of using shrink film as a cost-effective and efficient material for the rapid fabrication of microfluidic devices. The potential applications of this material in various fields such as the medical and biomedical industries, bacteria and algae culture and enumeration are noteworthy.

Design Optimization of Fins of a Sounding Rocket for Maximum Lift-to-Drag Ratio and Minimum Radar Cross- Section Area Using ANSYS

The optimization of a sounding rocket's fins is a crucial part of improving its performance. The geometric optimization of a sounding rocket's fins is presented in this paper. The main goal is to optimize the geometry for the minimum radar cross-section area and maximum lift-to-drag ratio. In CATIA, a 3D model was created. The L/D ratio was maximized using the ANSYS adjoint solver, and the radar cross-section area was minimized using ANSYS optimetrics. To determine the total RCS, the RCS of each fin was determined individually and then added together. Root, leading edge, tip, and trailing edge were the four parameters that were defined for the RCS optimization. The L/D ratio was increased by 8.3 times, and the RCS was decreased by 12% after optimization. Additionally, the body surface can be optimized further. The missile industry can benefit from the paper's findings.

Limit load of notched Ti-6Al-4V specimens under axial fatigue

Ti-6Al-4V is used to manufacture aircraft components, that are subjected to fatigue loads during their service life. These components exhibit flaws and are susceptible to impact damage. Therefore, it is important to study the fatigue behaviour of Ti-6Al-4V in the presence of defects to accurately evaluate the fatigue life of components. This paper reports the limit load of notched Ti-6Al-4V specimens not subjected to solution treatment and over-aging under axial fatigue. The tests are carried out in inert environments using a step loading procedure, with a load ratio R = 0. The limit loads of the specimens with a notch depth / width of the specimens’ gauge section ratio d / D = 0.0439 and d / D = 0.0877 are similar and higher than the limit load of the specimen with d / D = 0.1754 since the net area at the minimum cross section of the third specimen is much smaller than the areas of the other two specimens. The nominal stress at failure referred to the net area is similar for the fatigued specimens.

Characterization of upper airway and analysis of potential risk factor associated with OSA in patients with unilateral temporomandibular ankylosis and micrognathia deformities

ObjectiveTo ascertain the airway characteristics in patients with unilateral temporomandibular joint ankylosis and maxilla-mandibular deformities (UTMAMD) and investigate the potential risk factors associated with obstructive sleep apnea (OSA) among UTMAMD patients. MethodsAuthors conducted a retrospective single-center study to assess and compare study group consisting of a cohort of 32 patients diagnosed with UTMAMD between January 2011 and July 2022 with control group including 54 participants. The study group was further divided into two subgroups based on the presence or absence of OSA in patients. Parameters related to the upper airway were measured and analyzed using three-dimensional reconstruction of computed tomographic scans. The measurements of airway parameters were compared between study group and control group and between two subgroups. Pearson correlation analysis was used to identify the factors associated with the presence of OSA, and a multiple variable regression model was used to identify risk factors for OSA. ResultsAirway volume (VOL), Minimum cross-section area (min CSA), mean CSA, tilt in sagittal plane (TS), and tilt in sagittal plane (TC) in velopharynx; VOL, airway length (AL), min CSA, mean CSA, TS, TC, and airway deviation (AD) in glossopharynx; min CSA, TS, and AD in hypopharynx were found difference with significance between study group and control group. Lateral dimension/anterior-posterior dimension (LAT/AP) ratio in velopharynx and min CSA, TC, and LAT/AP ratio in glossopharynx were significant different between patients with UTMAMD with OSA and without OSA. ConclusionsThe upper airway of patients with UTMAMD exhibits significant narrowing and distortion, rendering them susceptible to suffer from OSA. Patients with UTMAMD and OSA demonstrate more elliptical airways, and the glossopharyngeal LAT/AP ratio is a predictive indicator for the occurrence of OSA.

The SKIF X-Techno Beamline Project

Beamlines nowadays installed at synchrotron radiation centers typically pose different and sometimes even incompatible requirements to X-ray beams being utilized. Some techniques require minimum attainable beam cross-sections in order to enable microbeam techniques with the sample mapping. To the contrary, relatively broad X-ray beams with the uniform intensity distribution are needed to address problems related to X-ray irradiation-based processing of materials or fabrication of components and devices with X-ray lithography approaches. The present paper describes the concept of a novel beamline named X-Techno proposed for the synchrotron radiation facility SKIF. It would use synchrotron beams as wide as 100 mm in the horizontal plane in different spectral ranges with either out of three experimental chambers to study materials and manufacture micro and nanostructures. The beamline will be specifically suitable for studies of physicochemical properties of materials under intense X-ray irradiation within the spectral range from 2 to 70 keV.

Experimental investigation on corroded stud connectors under strain rates effect

Shear connectors have been widely used in bridge and steel engineering to transfer the dynamic load effect between the neighbour elements. The shear connectors are exposed to moist air, and corrosion is unavoidable. An experimental investigation was conducted on the shear behaviour of corroded stud connectors with growing strain rates to study the effects of corrosion and strain rate on the shear capacity. Four series of specimens with different corrosion rates were tested. The electronic accelerating method was used to fabricate corroded studs with target corrosion rates. The corroded studs were loaded with five loading speeds to investigate the strain rate effects on the shear capacity. The fractured surfaces show that the corroded stud connectors have more tensile deformation in the loading process and a higher strain rate enhances the shear fracture other than tensile fracture. Based on the statistics of load-slip curves, we found that stud connectors with higher corrosion rates are more sensitive to dynamic load. However, corrosion cannot decrease the ultimate shear stress based on the minimum cross-section. For all corrosion rates, the relative ultimate shear strength grows with strain rate with a fixed growth rate.

Effective heat conduction evaluation of lattice structures from selective laser melting printing

Lattice structures are promising for the applications as heat exchange media since additive manufacturing technology is able to prepare the parts in complex shapes. Thermal conduction performance is one of the key indicators evaluating the heat transfer capability of heat exchange media, and it is quantified by the effective thermal conductivity. The present study is to evaluate the heat conduction performance of lattice structures used as lightweight materials in industries. In order to design and fabricate lattice structures with controllable thermal conduction performance, the effects of structure design variables such as topology, porosity, specific surface area, and cross-section area on effective thermal conductivity of selective laser melting processed lattice structures are investigated systematically by experimental and numerical approaches. The results show that either decreasing the porosity or specific surface area increases the effective thermal conductivity of specific lattice structures. It is also found that the effective thermal conductivity increases up to 50.67% when the minimum cross-section area is enlarged along with the main heat conduction direction under the same porosity and specific surface area.

Short-term outcomes in the upper airway with tooth-bone-borne vs bone-borne rapid maxillary expanders

BackgroundThis study compared the area and minimal section of the nasal cavity, nasopharynx, oropharynx, and hypopharynx in cases treated with different methods of microimplant-assisted expansion.MethodsBased on a pilot study to calculate the sample size, 30 patients with transverse maxillary deficiency over 14 years of age were retrospectively selected. These patients had received two different types of microimplant-assisted maxillary expansion treatment (MARPE and BAME). The patient underwent Cone-Beam computed tomography (CBCT) before and after treatment (mean time 1.5 months) with MARPE or BAME and upper airway measurements (volume and minimum cross-sectional area) were taken to assess upper airways changes and compare changes between the groups. A paired sample t-test was performed to evaluate the T0-T1 change of airway measurements obtained with MARPE and BAME, and a student t-test to compare changes in airway measurements between MARPE and BAME.ResultsThis investigation shows a statistically significant increase in total nasopharyngeal airway volume (0.59 ± 1.42 cm3; p < 0.01), total oropharyngeal airway volume (3.83 ± 7.53 cm3; p < 0.01) and minimum oropharyngeal cross-section (53.23 ± 126.46 mm2; p < 0.05) in all cases treated with micro-screw assisted expansion. The minimal cross-sectional area of the oropharynx ((79.12 ± 142.28 mm2; p < 0.05) and hypopharynx (59.87 ± 89.79 mm2; p < 0.05) showed significant changes for cases treated with BAME. As for the comparison between cases treated with MARPE and BAME, no differences in upper airway changes have been observed, except for the minimum cross-sectional area of the nasal cavity, which increases for MARPE (52.05 ± 132.91 mm2) and decreases for BAME (-34.10 ± 90.85 mm2).ConclusionsA significant increase in total area and minimal section at the level of nasopharynx and oropharynx was observed in cases treated with BAME. Regarding the comparison of MARPE and BAME treatments, no differences were found in the total airway volume and minimal section in upper airway except for the minimum cross section of the nasal cavity that increases for MARPE and decreases for BAME.

Analysis of the efficacy of azelastine nasal spray combined with mussel mucin in the treatment of allergic rhinitis and the influence of peripheral blood CCL26 and CCR3 levels.

A retrospective study was conducted to investigate the efficacy of azelastine nasal spray combined with mussel mucin in the treatment of allergic rhinitis (AR) and the effects of CCL26 and CC chemokine receptor-3 (CCR3). A total of 80 patients with AR admitted to our hospital from March 2020 to March 2022 were included as the research objects. All subjects were divided into two groups according to the different therapeutic strategies by reviewing the patient's treatment. The control group (n = 40) was given azelastine nasal spray, while the study group (n = 40) was treated with a combination of mussel mucin and azelastine nasal spray. The clinical efficacy, clinical symptoms, and sleep quality improvement of the two groups were calculated and compared retrospectively. The serological indexes were compared, and the incidence of adverse reactions between the two groups was calculated retrospectively based on the patient's medical records. In the study and control groups, the effective rate was 95.00% and 72.50%. After treatment, the symptom scores of nasal congestions, nasal itching, sneezing, and runny nose and the total score of Pittsburgh sleep quality index (PSQI) in the study group were remarkably less. After treatment, the serum levels of sVCAM-1, interleukin-4 (IL-4), and immunoglobulin E (IgE) were decreased, and the levels of IL-12 were upregulated. Following treatment, Minimum nasal cross-section (NMCA) and total nasal resistance (TNR) at 75Pa in the study group were reduced more noticeably (p < 0.05). After treatment, the expression levels of CCL26 and CCR3 in peripheral blood were significantly decreased. In the control and study groups, the incidence of adverse reactions was 7.50% and 10.00%. Azelastine nasal spray combined with mussel mucin is effective in the treatment of allergic rhinitis, which can effectively improve patients' clinical symptoms, alleviate nasal ventilation disorders, reduce inflammatory reactions, and improve sleep quality. This strategy of combined treatment is safe and, therefore, worth advocating.

Digital rock modeling to quantify scale dependence of petrophysical measurements in burrowed reservoir rocks: An example using Thalassinoides

Recent evaluations of burrow connectivity have shown that burrow morphology, abundance, and size impact the sampling scheme required for faithfully representing permeability in the laboratory. Quantifying these controls to design appropriate sampling is essential. This study illustrates a new approach using multipoint statistics modeling and applies it to Thalassinoides, to simulate a range of burrow abundances and sizes, and then interrogates the outcome to develop a statistical model that allows sampling strategies to be designed. Our workflow started with digital models that were known to have open or permeable Thalassinoides that connected one side of the model volume to another, (i.e., high permeability). We cut the model volumes into 540 digital samples with a range of burrow abundance, burrow size and sample cross section. The Thalassinoides showed no cross-sample connectivity in 173 (32%) samples; the remaining 367 (68%) showed cross-sample Thalassinoides connectivity. The data on burrow abundance, burrow size, and sample dimensions (as independent variables) and the result of samples representing Thalassinoides connectivity or not (as a dependent variable), was analyzed using logistic regression modeling. An important outcome from the logistic regression model is an equation that provides a probability of Thalassinoides connectivity across samples, given burrow abundance, burrow size, and sample dimension inputs. This equation has practical applications in determining the minimum sample cross-sections and sample lengths needed for samples to adequately represent the permeability. As examples, for samples with cross sections similar to core plugs and full diameter core, given various burrow percentages and sizes, only 37% yield burrow connectivity across any and all sample lengths. For the rest, our data on the largest connected burrow length allows for calculation of the probabilities of samples of typical lengths being representative of the burrow connectivity. Thus, researchers can assess the likelihood of their samples representing Thalassinoides connectivity given a range of burrow abundance, burrow size, sample cross section and sample length. The spreadsheet to make these calculations and lookup tables are provided as digital accessory files. The example using Thalassinoides provides proof-of-concept of a methodology that should be broadly applicable to any given burrow morphology. An algorithm and lookup table that can be modeled for each given burrow morphology with an appropriate training image.

Carbon footprint of reinforced concrete columns with and without supplementary cementitious materials

The construction sector consumes a large quantity of natural resources and generates a great deal of carbon dioxide emissions and wastes, affecting its sustainability. Replacing Portland cement with supplementary cementitious materials (SCM) could reduce the environmental impact. This paper examines the carbon footprint of reinforced concrete columns. It focuses on the influence of increasing the steel cross-section and reducing the clinker factor by replacing Portland cement with SCM. Eighteen concrete mixtures were selected and classified according to the specified compressive strength at 28 days of curing using binary and ternary blended cements. Columns were designed consisting of such concretes and employing different reinforcing steel cross-sections. The life cycle assessment was conducted on ISO 14040 standard. The embodied carbon dioxide (ECO2) of the reinforced concrete columns was determined. The results show that the higher the compressive strength of concrete, the lower the carbon footprint of the columns. Concretes with a high volume of SCM replacement and low compressive strength at 28 days do not show the lowest carbon footprint since it requires a greater volume of material to withstand the bearing capacity. The carbon footprint of the columns increases as the steel section increases. Furthermore, increasing the compressive strength of concrete is less beneficial for reducing the carbon footprint of the column when the steel cross-section is increased. Portland cement is the component material of concrete that contributes the most to the concrete carbon footprint, and steel has the highest ECO2/tonne. Replacing Portland cement with SCM reduces ECO2 at one point of the life cycle and may increase the material volume and ECO2 at another. The lowest carbon footprint of compressed reinforced concrete elements is achieved for the higher-strength concretes and the minimum steel cross-section.

Fabrication of core-shell structure NiFe2O4@SiO2 decorated nitrogen-doped graphene composite aerogels towards excellent electromagnetic absorption in the Ku band

The fabrication of advanced electromagnetic wave absorbents with wide bandwidth, robust absorption and small filling ratio remains a great challenge. In this work, the ternary composite aerogel of nitrogen-doped reduced graphene oxide/nickel ferrite@silicon dioxide modified by amino groups (NRGO/NiFe2O4@m-SiO2) was synthesized via the three-step route of solvothermal synthesis, Stöber method and hydrothermal self-assembly. Microscopic morphology characterization results indicated that the acquired binary and ternary magnetic composite aerogels exhibited a special three-dimensional porous network architecture. Moreover, the electromagnetic absorbing capacity of NRGO/NiFe2O4 composite aerogel could be obviously enhanced by coating SiO2 and modifying amino groups on the surfaces of SiO2. Remarkably, the as-fabricated NRGO/NiFe2O4@m-SiO2 composite aerogel possessed the broadest effective absorption bandwidth of 7.04 GHz (10.96–18.0 GHz) and robust absorbing intensity of −30.8 dB at 2.1 mm under a small filling ratio of 12.5 wt%. It was worth mentioning that the optimal minimum reflection loss could reach −56.0 dB when the matching thickness was increased to 3.4 mm. Besides, a minimum radar cross section value of −51.1 dB m2 could be achieved in the far-filed condition. The special porous network structure and magnetodielectric synergy in the ternary composite aerogel optimized the electromagnetic impedance, and notably enhanced the electromagnetic absorbing capacity. It was believed that this study would provide a novel approach for the construction of highly efficient carbon-based electromagnetic wave absorbers.

Airway Resistance and Respiratory Distress in Laryngeal Cancer: A Computational Fluid Dynamics Study.

Obstructive upper airway pathologies are a great clinical challenge for the airway surgeon. Protection against acute obstruction is critical, but avoidance of unnecessary tracheostomy must also be considered. Decision-making regarding airway, although supported by some objective findings, is largely guided by subjective experience and training. This investigation aims to study the relationship between clinical respiratory distress and objective measures of airway resistance in laryngeal cancer as determined by computational fluid dynamic (CFD) and morphometric analysis. Retrospective CT and clinical data were obtained for series of 20 cases, defined as newly diagnosed laryngeal cancer patients who required admission or urgent airway surgery, and 20 controls. Cases and controls were matched based on T-staging. Image segmentation and morphometric analysis were first performed. Computational models based on the lattice Boltzmann method were then created and used to quantify the continuous mass flow, rigid wall, and constant static pressure inlet boundary conditions. The analysis demonstrated a significant relationship between airway resistance and acute obstruction (OR 1.018, 95% CI 1.001-1.045). Morphometric analysis similarly demonstrated a significant relationship when relating measurements based on the minimum cross-section, but not on length of stenosis. Morphometric measurements also showed significance in predicting CFD results, and their relationship demonstrated that airway pressures increase exponentially below 2.5 mm. Tumor subsite did not show a significant difference, although the glottic subgroup tended to have higher resistances. Airway resistance analysis from CFD computation correlated with presence of acute distress requiring emergent management. Morphometric analysis showed a similar correlation, demonstrating a radiologic airway assessment technique on which future risk estimation could be performed. 4 (case-control study) Laryngoscope, 133:2734-2741, 2023.

Effect of louver baffle on the stability and separation performance of the gas-solid separation fluidized bed

Bed density stability is often the dominant factor restricting the efficiency of coal beneficiation in gas-solid separation fluidized beds (GSSFB). Here, in order to improve the fluidization quality, a louver baffle was introduced into a conventional GSSFB, converting it into a so-called louver baffle separation fluidized bed (LBSFB). The influence of the louver baffle on the fluidization characteristics and coal separation efficiency of the GSSFB were investigated using a combination of experiments and numerical simulations. The minimum fluidized gas velocity, pressure drop, and cross section density of the bed were measured when baffle was placed at two different positions (H=40 mm and H=80 mm). Meanwhile, the evolution of bubble generation and particle flow were simulated when the baffle was placed at H= 40 mm and the operating gas velocity was 7.52 cm/s. The results showed that the use of a single guide baffle could effectively break up the bubbles in the bed, inhibit bubble growth and particle backmixing, and restore the uniform distribution of the updraft. When the louver baffle was installed at a height of H = 40 mm and the superficial gas velocity was 7.52 cm/s, the standard deviation of radial density fluctuation in the bed was reduced to 0.028 g/cm3, which is more than 35% lower than that of the conventional GSSFB, and that of the axial density fluctuation was reduced to 0.146 g/cm3. Under these conditions, the separation of 6–13 mm raw coal in a LBSFB resulted in a clean coal yield of 69.97% and a probable error, E, value of 0.082 g/cm3