Honeycomb Block Research Articles

THE SYNTHESIS, STUDY OF PHYSICOCHEMICAL PROPERTIES, AND EVALUATION OF CATALYTIC ACTIVITY OF A THREE-WAY CATALYST MODIFIER CONTAINING EUROPIUM (III) OXIDE

Modification of the applied Pt-containing catalysts with rare-earth metals is one of effective ways to increase their activity and resistance to thermal deactivation, which is associated with both an increase in thermal stability of the texture and structure of the carrier material and an increase in the degree of dispersion and resistance to sintering of the applied platinum metals (PM) when exposed to high temperatures. Conflicting data make it difficult to select a suitable modifier for the use as part of a three-way catalyst in the exhaust treatment system of gasoline-powered cars, whose function is to simultaneously convert CO, CxHy and NOx. In this work, the effect of europium-modified Pt-containing γ-Al2O3 -based catalyst on its physicochemical properties and activity in the oxidation of CO, CxHy, and NOx reduction processes was evaluated. The catalytic activity was evaluated by passing a gas mixture simulating the exhaust of a gasoline-powered car through the catalyst applied onto the surface of a cylindrical honeycomb block with simultaneous measurement of the degree of conversion of toxic components into relatively non-toxic CO2, N2 and H2O in the temperature range from 1000C to 4000C. The modification of the Pt/γ-Al2O3 catalytic system with europium was shown to enhance the activity in all three reactions studied, indicating a great potential for the use as a modifier of a three-way catalyst

ТЕОРЕТИЧЕСКИЕ ОСНОВЫ И ПРАКТИКА ДИАГНОСТИКИ ЭКОЛОГО-ПОЖАРООПАСНЫХ АВАРИЙНЫХ РЕЖИМОВ ЭКСПЛУАТАЦИИ КАТАЛИТИЧЕСКИХ СИСТЕМ АВТОТРАНСПОРТА

A kinetic model of the processes of chain oxidative reactions in automotive catalytic converters and PM2.5 soot particle filters of a honeycomb block design has been developed. Calculations according to the model confirmed the emergency modes of operation of converters, uncontrolled heat growth of more than 261683 kJ/h and, as a consequence, the oxidation temperatures of CO, CH, soot with melting and destruction of catalyst carrier matrices. It is shown that the causes of extreme neutralization modes can be malfunctions of electronic catalytic systems, increased sulfur content in fuel and oil, corrosion of fuel equipment parts, overheating of the engine and turbocharger. It is shown that the emergency heating of the converter is associated with an increase in the risk of car fire. An original method for monitoring the environmental-fire hazardous modes of operation of catalytic converters based on the modernization of the standard diagnostic procedure in accordance with GOST 33997-2016 (TR TS 018/2011) is proposed.

Methodology for Developing a Macro Finite Element Model of Lithium-Ion Pouch Cells for Predicting Mechanical Behaviour under Multiple Loading Conditions

To assist in light weighting of electric vehicles by improving the volumetric and gravimetric energy density and the structural performance of the battery pack, a modelling methodology based on a macro finite element model of a pouch cell has been developed. This model treats the core cell structure as a homogeneous orthotropic honeycomb block with the pouch material being defined as an orthotropic fabric with compressive stress elimination. The model considers five compression and bending load cases simultaneously and allows a level of element discretisation that is computationally efficient and appropriate for inclusion in full vehicle and sub-system simulations. The methodology is scalable in that it can be applied to a range of chemistries, external geometries and internal cell constructions. When considering stacks of cells, the model is predictive for both lateral compression and three-point bend, but further work is required to improve the confined compression response.

Three-dimensional electrochemical degradation of p-aminophenol with efficient honeycomb block AC@Ti-Cu-Ni-Zn-Sb-Mn particle electrodes

Emerging contaminants such as pharmaceuticals has been one of the most challenging environmental problems. In this work, we developed a one-step facile sol–gel method of loading TiO2, CuO, NiO, ZnO, Sb2O3 and MnO onto honeycomb block activated carbon (AC@Ti-Cu-Ni-Zn-Sb-Mn), further applying as particle electrodes in a three-dimensional electrochemical system for the efficient degradation of p-aminophenol (PAP). Factors associated with the preparation of AC@Ti-Cu-Ni-Zn-Sb-Mn particle electrodes were investigated. The AC@Ti-Cu-Ni-Zn-Sb-Mn particle electrodes were analyzed by scanning electron microscope (SEM), energy dispersive spectrum analysis (EDX), X-Ray Diffraction analysis (XRD), Brunner-Emmet-Teller (BET) and X-ray Photoelectron spectroscopy (XPS). The effects of conductivity, pH value, aeration intensity, current density, conductivity and initial concentration on PAP degradation were also studied. Importantly, the PAP degradation results show that the activity of the particle electrodes supported by block honeycomb activated carbon is much better than that of the particle electrodes supported by granular activated carbon. The removal efficiency of PAP achieved approximately 99.87% under the optimized condition. The pathway study suggested that the quinoneimine is the major intermediate during the three-dimensional electrochemical degradation and OH radicals play important roles in the reaction. Overall, its facile fabrication and efficient electrochemical degradation performance indicate that the proposed honeycomb block particle electrodes have potential for practical applications of refractory organic pollutants.

Method for the Optimal Positioning of the Cutter at the Honeycomb Block Cutting Applying Computer Vision

The problem of optimal cutting of honeycomb blocks is considered in the article. The urgency of using irregular shapes application cutting from honeycomb blocks made of modern composite materials is substantiated. The problem is to obtain a cut of a given shape from honeycomb blocks. The optimal cutting plane of the single cell face of a honeycomb block is found on the basis of calculations for the stability and stretching force in adjacent faces applying a finite element method. The problem of obtaining faces and nodal points of a honeycomb block when calculating the coordinates of the optimal cut points of a real honeycomb block using machine vision methods. The most suitable algorithms, a part of the OpenCV library, are considered. The authors decided to develop their own algorithm for recognizing an irregular cellular structure since the existed algorithms did not solve the stated problem. As opposed to existing algorithms, the proposed one finds all the nodal points and faces even on the deformed sections of the honeycomb block avoiding false faces. The method helps to find coordinates of all nodal points and determine the connection of adjacent points with a face. As a result, real faces, not perfect geometrically, are replaced by line segments. The test result proves its correctness and practical applicability. The proposed method solves an optimal cutting problem of aluminum honeycomb block. It should be noted that the proposed method is customizable and can be applied to any honeycomb or cellular panels.

Application of sequential processing of computer vision methods for solving the problem of detecting the edges of a honeycomb block

The article describes the application of the Hough transform to a honeycomb block image. The problem of cutting a mold from a honeycomb block is described. A number of image transformations are considered to increase the efficiency of the Hough algorithm. A method for obtaining a binary image using a simple threshold, a method for obtaining a binary image using Otsu binarization, and the Canny Edge Detection algorithm are considered. The method of binary skeleton (skeletonization) is considered, in which the skeleton is obtained using 2 main morphological operations: Dilation and Erosion. As a result of a number of experiments, the optimal sequence of processing the original image was revealed, which allows obtaining the coordinates of the maximum number of faces. This result allows one to choose the optimal places for cutting a honeycomb block, which will improve the quality of the resulting shapes.

Testing and modeling tearing and air effect of aluminum honeycomb under out-of-plane impact loading

For the deformable barrier often used in full-car crash tests, which mainly consists of aluminum honeycombs, tearing in the thin-walled structure of honeycomb is a common phenomenon induced by non-uniform large deformation, and influence of the entrapped air proves non-negligible when the honeycomb undertakes dynamic loading. Both the localized tearing and the entrapped air affect the deformation pattern and the global mechanical response of the honeycomb in crash scenarios. The present paper documents development of an equivalent finite element model (FEM) for the aluminum honeycomb focusing on these two effects as well as the relevant experimental study. Four tests of the honeycomb block with out-of-plane loading, i.e., uniform compression, compression-shear along two orthogonal cross-sections and indentation, are performed at quasi-static and dynamic loading speeds to quantitatively address the tearing effect and the air effect on the entire mechanical response. It is also found that the honeycomb exhibits different tearing mechanisms along the two orthogonal cross-sections. In developing the solid-element based equivalent model for the honeycomb, airbags are introduced to characterize the air effect, and beam elements with failure criteria are embedded to simulate the tearing effect. Parameters of the airbags and the beam elements in the equivalent FEM are determined based on different combinations of the honeycomb tests. Simulations of all the loading cases in the present study achieve good agreement with the test results in terms of the global mechanical response and overall deformation pattern, reflecting feasibility of the equivalent FEM.

Analysis of energy dissipated by damping for paper honeycomb sandwich plate-block system

The vibration transmissibility of paper honeycomb sandwich plate was tested and the vibration transmissibility curve was simplified and characterized. Based on the basic principle of vibration mechanics, the equation for calculating the energy dissipated by damping of paper honeycomb sandwich plate-block system during vibration was deduced. Furthermore, the effects of honeycomb structural parameters (cell length, sandwich plate thickness) and block mass on the damping energy dissipation were analyzed. The results showed that the curves of vibration transmissibility for paper honeycomb sandwich plate can be divided into three regions: plateau region, amplification region, and attenuation region. The vibration transmissibility ratio in different regions can be expressed as functions of frequency. The energy dissipated by damping of paper honeycomb sandwich plate-block system depends on its vibration transmissibility. If the vibration transmissibility ratio–frequency curve is obtained, the damping energy dissipation of the system can be calculated. The total energy dissipation of paper honeycomb sandwich plate-block system during vibration is about equal to that of plateau region, and the energy dissipated in amplification and attenuation region can be neglected. Different honeycomb structural parameters have the same effect on the damping energy dissipation of the system. Block mass has little effect on the damping energy dissipation in plateau region and the total energy dissipation during vibration but has a greater impact on the energy dissipation in the amplification and attenuation regions. The purpose of this paper is to provide a basic method for calculation of energy dissipated by damping and evaluation of anti-vibration property for packaging material.

蜂巢砌块挡土墙结构安全性分析

蜂巢砌块挡土墙结构安全性分析

Fundamental Study of Dehumidification and Heating by Pre-regenerated Silica gel Honeycomb Block for Electric Vehicles

Fundamental Study of Dehumidification and Heating by Pre-regenerated Silica gel Honeycomb Block for Electric Vehicles

Buoyancy-opposed volumetric solar receiver with beam-down optics irradiation

This paper describes a volumetric solar receiver that is vertically integrated with beam-down optics for condensed light irradiation. The heat-transfer performance of a silicon carbide honeycomb receiver was investigated using a 30-kWth solar simulator and numerical simulation. The experiments achieved an air temperature of 840 K at the receiver outlet by varying the operational parameters. Numerical simulations were performed for a vertical honeycomb block with beam-down irradiation and a horizontal honeycomb block with tower-type irradiation to elucidate the effects of buoyancy. Three blocks with different sizes were simulated for a variety of operational parameters. When the block was oriented vertically, the flow and temperature fields remained nearly symmetric in and near the receiver. In contrast, when it was oriented horizontally, the flow and temperature became asymmetric, with the hot spot moving toward the receiver's side wall and the stream in the receiver being reversed. The vertical orientation's robustness to buoyancy effects prevented any reduction in the receiver efficiency or outlet temperature and suppressed the thermal leakage.

Influence of internal pressure on the out-of-plane dynamic behavior of circular-celled honeycombs

The out-of-plane dynamic behavior of circular-celled honeycombs is studied by both numerical simulations and theoretical analysis. The influences of the internal pressure, the crushing velocity and the cell-wall thickness on the honeycombs’ deformation modes and mechanical characteristics are investigated. The results show that the honeycomb block without pressure inside collapses in Diamond mode, while the deformation mode turns into Petal mode and then Coin mode with the increase of internal pressure. The critical internal pressure for the transformation between deformation modes increases with the crushing velocity but decreases with the cell-wall thickness. The honeycombs’ plateau stress under Diamond mode is the highest and then decreases with the internal pressure under Petal mode. Once Coin mode appears in the honeycomb, the honeycomb's plateau stress hardly depends on the internal pressure. Besides, it is shown that the honeycombs’ plateau stress increases with both the wall thickness and the crushing velocity. In view of the fact that Coin mode is unique for circular-celled honeycombs with high internal pressure, an analytical model is built to deduce the plateau stress of circular-celled honeycombs deformed with Coin mode. The analytical predictions are in good agreement with the numerical simulation results.

Mechanical behavior of composited structure filled with tandem honeycombs

Abstract Recently, how to significantly improve the energy absorption property of honeycomb structures have drew a lot of attention. As a potential excellent way out, tandem honeycomb has sprang up and rapidly gained popularity. In the present work, comprehensive experiments of tandem hexagonal honeycomb structures subjected to axial compression has been conducted with general, strength gradient, and pre-compressed specimens, respectively. Extensive mechanical behaviors of kinds of tandem honeycomb structures have been demonstrated. Although highly random deformation sequences were observed in those specimens, the tandem honeycomb structure still performed as perfect response as in the general pieces of honeycomb block under compression load. In addition, the tandem honeycomb structure performed a better mechanical behavior and showed a stable, rectangular-like compression history after pre-compression, no initial peak force appeared for subsequent segments. Based on this, numerical simulations for tandem honeycomb-filled energy absorber were conducted using homogenized constitutive model which was validated by experiments. Two typical conformation modes, lateral reinforced structure and multi-cell structure were discussed through numerical analyses on matching effect and multi-cell effect. The results turned out that the lateral resistance has significant influence on deformation mode and filling tandem honeycomb into multi-cell tubes evidently improves the mechanical behavior of such structures. All the achievements shed a light on the design of impact energy absorbers which consisted of composited honeycomb cores.

Oxidation of ammonia on woven and knitted platinoid gauzes

The results from pilot tests of catalytic systems equipped with 7–12 woven or 5–14 knitted platinoid gauzes in the oxidation of ammonia are considered. OAO Yekaterinburg Non-Ferrous Metal Processing Plant produces gauzes of the two types: Pt092 0.092-mm wire woven and Pt076 0.076-mm wire loosely knitted (large-mesh) gauzes. Both types of gauzes are made of PdRdRu 15-3.5-0.5 alloy (referred to as alloy no. 5) and have the following elemental composition: Pt, 81%; Pd, 15%; Rh, 3.5%; Ru, 0.5% (STO (Branch Standard) 00195200-013-2007 and STO (Branch Standard) 00195200-014-2007). The third type is 0.076-mm tightly knitted (small-mesh) gauzes (Uncore, Germany), which differ from the Russian knitted Pt076 gauze by their greater mass and external surface area per unit reactor cross section. The effect of the mass, external surface area, and free volume of woven and knitted platinoid gauzes on the yield of nitrogen oxide is studied in this work, and the residual concentration of ammonia downstream of a stack of gauzes is determined in dependence on their number. The efficiency of the unit surface of knitted gauzes depends on the influence exerted by transfer phenomena and the direct homogeneous ammonia reduction of nitrogen oxide in the free volume of a platinoid catalyst stack. Loosely-knitted Pt076 gauzes are less efficient than woven Pt092 gauzes within a ≥91.5% range of nitrogen oxide yields. Tightly knitted gauzes are suitable for use within a ≤94.5% range of nitrogen oxide yields. Yields equivalent to those obtained on woven gauzes cannot be attained on tightly knitted gauzes even after their external surface area is enlarged considerably. Maximum nitrogen oxide yields (≈95%) are attained on Pt092 woven gauzes. From the results of our tests of loosely and tightly knitted platinoid gauzes, it follows that the latter (with less free volume in a stack) are preferable for use. The free volume of gauzes and the fraction of ammonia for nontargeted conversion can be minimized by placing a smaller number of loosely knitted platinoid gauzes on a regular honeycomb block catalyst or packing bed.

Mechanical Behavior of Polycarbonate Circular Honeycombs under in-Plane Biaxial Compression

In-plane equi-biaxial compression tests were conducted quasistatically on polycarbonate circular honeycombs in a conventional universal testing machine with a specially designed test rig. In view of the complex characteristics of the deformation in a honeycomb block under biaxial compression, the focus was put on the initiation and evolution of deformation inhomogeneity. An inhomogeneity index, Iinh, is defined as a function of the overall compression of a sample to quantify the severity of the deformation inhomogeneity of the honeycomb block; and it facilitates quantitative comparisons among the results under various loading conditions. To examine the role of the friction between the honeycomb sample and the test rig, and to explore the effect of dynamic loading, finite element analysis is carried out to simulate the collapse process of a circular honeycomb block under equi-biaxial compression. The numerical simulation also reveals the transition from a global collapse mode (although inhomogeneous) to a progressive collapse mode at a critical loading velocity, which is further studied by the wave trapping theory.

The Modeling and Application of Moving Deformable Barrier Model with Beam Element

According to GB 20071-2006 regulation, the finite element model of aluminum honeycomb block was built with beam elements, and the corresponding moving deformable barrier (MDB) model was validated. Side impacts between a vehicle and the MDBs which were set up with beam elements and solid elements respectively, were simulated. The velocities of five key points on the B pillar and the door were measured and compared with the test data. The results show that the demands of the regulations could be achieved by the MDB with beam elements, while at the same time, the efficiency of computing is improved and better local characteristic is obtained.

G111 セラミックス製ハニカム状蓄熱体を利用した小型熱再生燃料改質器の開発 : 第2報 イオン電流測定による反応帯検出(OS5 水素・燃料電池)

A tubular-type compact fuel reformer with ceramics honeycomb blocks was fabricated in this study, and was applied to produce hydrogen from methanol, focusing on partial oxidation reaction (POR). In the authors' previous study, 10% enhancement of hydrogen production was observed by placing the reaction region between the two honeycomb blocks (Case-2), compared with a single honeycomb block insertion (Case-1). In the present study, the reaction characteristics of the reformer were investigated by identifying the location and the shape of the reaction region. The streamwise temperature distributions were measured in detail by using a transversal-type thermocouple, and the ion current distributions corresponding to the reaction region were detected by an electrostatic probe. By both measurements, it was confirmed that the reaction front of Case-2 was transferred to more upstream position compared to Case-1. This result suggests that there is an enhancement of preheating of premixed gas, which is due to the heat regeneration of exhaust gas by means of radiation energy exchange between the two honeycomb blocks, and consequently the reaction front moved to more upstream location.

アルコール系小型燃料改質器の熱再生による反応制御手法(熱工学,内燃機関,動力など)

A compact tubular-typed fuel reformer was fabricated in this study, and was applied to produce hydrogen from methanol, focusing on the partial oxidation reaction (POR). The reformer was composed of a stainless steel pipe as the reactor exterior and ceramic honeycomb blocks inserted in two locations of the pipe. The upstream-side honeycomb blocks are expected to enhance the reforming stability and reaction efficiency by performing as an effective heat exchanger to the reactant gas. In addition, the downstream-side block acts as a heat regenerater which absorb the heat energy of the exhaust gas. The maximum hydrogen production was achieved in the condition of equivalence ratio, around 3.5, which is fuel rich condition of POR. The downstream-side honeycomb block enhanced the reforming efficiency by 8% at the maximum. This improvement was caused by the temperature rise at the reaction region due to the insertion of the downstream-side honeycomb block, while gas temperatures in the far-most downstream region became lower. These results indicate that the thermal energy possessed by the reforming gas was regenerated to the reaction region by the downstream-side honeycomb block.

The inhomogeneous deformation of polycarbonate circular honeycombs under in-plane compression

In-plane uniaxial and equi-biaxial compression tests were conducted quasi-statically on polycarbonate circular honeycombs. While the uniaxial compression tests were easy to implement, a special test rig was designed to carry out the in-plane ( x– y) equi-biaxial compression tests in a conventional universal testing machine. The deformation characteristics of a honeycomb block under uniaxial compression are quantitatively described by tracking the variations of the cells’ parameters, such as the area strain and the angle of cells, during the deformation process of the honeycomb. As the distribution of the deformation within the honeycomb block under biaxial compression is much more complex, a series of color maps based on the area strain of each cell are produced to demonstrate the inhomogeneous deformation among the cells in the honeycomb block, by which the initiation of deformation inhomogeneity and its evolution in the honeycomb block are characterized. To identify the role of the friction between the honeycomb sample and the test rig, finite element analysis is conducted to simulate the collapse process of the circular honeycomb under equi-biaxial compression. Furthermore, an inhomogeneity index, I inh, is defined as a function of the overall compression of a sample to quantify the severity of the deformation inhomogeneity of the honeycomb; this index facilitates quantitative comparisons among the results under various loading conditions. It is found that the value of I inh of a sample is closely related to some internal factors, such as the localization band of deformation and the deformation pattern of cells.

OS0609 内部点対称性を有するハニカム構造物のtwo-scale解析(OS06-02 マルチスケール解析2,OS06 微視構造を有する材料の変形と破壊(1))

本研究では,均質化法に基づくtwo-scale解析手法を用いて,内部点対称性を有する弾塑性六角形ハニカム構造物が平面パンチによるインデンテーションを受けたときの変形挙動解析を行う.ハニカム構造物のセル配列は,zigzag型とarmchair型の2種類を用い,それぞれのミクロ構造がマクロ変形特性に与える影響について検討する.さらに,two-scale解析条件に相当するfull-scale解析を行い,two-scale解析結果の妥当性を検討する.