Orthogonal Experimental Method Research Articles

Optimization Based on Computer Fluid Dynamics Finite Element Method Automotive Cooling Fan Structure

With the continuous improvement of vehicle comprehensive technology, the heat load generated by automotive engine systems, hydraulic systems, and other devices also increases. Therefore, improving the heat dissipation efficiency of the cooling system is a key technology that cannot be ignored in the current vehicle development process. The car cooling fan is an important component of the cooling system, and its working characteristics will directly affect the cooling effect of the engine. This article uses the finite volume method of computer fluid dynamics to optimize the structure of a heat dissipation fan, analyze and define the flow field control volume required for its numerical calculation, use structured and unstructured grids to discretize the internal flow field region, select pressure inlet and pressure outlet boundary conditions, and simulate and analyze the fluid flow in the radiator based on fluid dynamics theory calculations. The orthogonal experimental method was used to analyze various performance indicators during the experimental process. The results showed that the comprehensive performance of the No. 3 optimized cooling fan was the best, with a 10.45% increase in static pressure efficiency, a 14.03% increase in dynamic pressure efficiency, and an 11.26% increase in maximum flow velocity. The optimized fan flow field streamline became more full and uniform, significantly improving the fluid dynamics performance of the air in the cooling system.

Comprehensive evaluation on deposition and heat transfer performance of the mixed tube bundle based on orthogonal experimental study

Deposition on heat exchange surfaces is an urgent problem to be solved to achieve efficient utilization of energy in thermal equipment. To mitigate deposition and the resultant heat attenuation, this work proposes a mixed tube bundle strategy of inserting attached cylinders behind the tube bundle, which can effectively meet the design requirements of high anti-deposition performance, high heat transfer efficiency, and low flow resistance. An integrated dynamic model for deposition is developed to elucidate the effect of ash particles on deposition, flow, and heat transfer characteristics. Based on the inverse distance weighting interpolation, a dynamic mesh smoothing technique is employed to simulate the evolving deposition layer on the heat transfer surface. In addition, the L16(43) orthogonal experimental design method is adopted to study the influence of the arrangement angle, diameter, and distance to the primary bundle of the attached cylinder on the overall performance, and determine the optimal scheme. The results show that deposition in the cases using the mixed tube bundle strategy has significantly decreased. The weakening effects of the attached cylinder on the deposition of small-medium particles and large-sized particles are due to the inhibition of vortex development in the gap of tube bundle and the deviation of the motion trajectory, respectively. The novel design exhibits the lowest deposition mass Mdep = 1.12 g and the best comprehensive performance PEC = 1.14 under the condition of the arrangement angle of 50°, the diameter of 10 mm, and the distance between the primary bundle of 5 mm. The obtained results can provide reference schemes and guidance for the optimization of the design of heat exchange equipment and accessory devices.

Investigation of Machining Parameters for Turning Process

Manufacturing industries mainly concentrates on how to minimize the cost of the products. The process planers have to prepare the process plan of the product based on the availability of the recourses. All the information is available in the plan including inspection and delivery date of the product. Based on the recommendation of the manufacturing and inspection methods, components are produced at affordable cost. Most of the research work concentrated on selection of machining parameters using optimization techniques and also prove that the machining time / cost were minimized for the particular components / operations. In this work, tool nomenclature is to be considered for the investigation for selection of machining parameters. Work presents an experimental investigation of the influence of the three most important machining parameters of depth of cut, feed rate and spindle speed on surface roughness during turning of aluminium alloy. In this study, the design of experiment which is a powerful tool for experimental design is used to optimize the machining parameters for effective machining of the work piece. L9 orthogonal array experimental design method as well as analysis of variance (ANOVA) is used to analyse the influence of machining parameters on MRR & Machining Time. Two different grade of aluminium alloy i.e. AL 6063 & AL 6068 were machined with input parameters of depth of cut and speed. The output parameters are MRR and machining time. Based on the results empirical equations are formed and optimized results are validation .The optimal results are recommended to manufacturing industries.

Computational Study on Influence Factors and Vortical Structures in Static Drift Tests

This paper conducted a computational study on the KCS benchmark model at static drift conditions. At the first instance, the roles played by the grid size, turbulence model, and time step are qualitatively and quantitatively analyzed with the orthogonal experimental method (OEM). After the verification of simulated results compared with experimental data in a Static Oblique Towing Test (OTT), hydrodynamic performance is obtained with the employment of the SST κ-ω turbulence model. The grid size is set as 0.07 m while the time step as 0.01 s. The characteristics of the wake field are illustrated in different forms, such as contours of the free surface, distribution of pressure and hydrodynamic forces, variation of turbulent kinetic energy (TKE), and so on. For a deep insight into the physical mechanisms of the asymmetrical flow field, the Detached Eddy Simulation (DES) method is also utilized to capture vortical structures occurring around the hull, in comparison with results obtained through the Reynolds Averaged Navier Stokes (RANS) model. With the aim of a hydrodynamic derivative estimation or detailed flow characteristics analysis, corresponding selections of the computational method are disparate.

Synergistic Effects of Humic Acid, Biochar-Based Microbial Agent, and Vermicompost on the Dry Sowing and Wet Emergence Technology of Cotton in Saline–Alkali Soils, Xinjiang, China

Soil amendments such as humic acid (HA), a biochar-based microbial agent (M), and vermicompost (V) can improve soil quality and promote crop growth. However, it remains unclear whether the co-application of the three soil amendments (HMV) has a synergistic effect on alleviating soil quality deterioration obstacles caused by dry sowing and wet emergence technology in Xinjiang cotton fields. A three-year field experiment was conducted in saline–alkali soils using plastic-film-mulched drip irrigation in Xinjiang, China. Through the orthogonal experiment method, the application amounts of HA, M and V were 75 kg ha−1, 75 kg ha−1 and 225 kg ha−1 respectively in 2021. In 2022, three application amount gradients were used for HA, M and V: 60 kg ha−1, 90 kg ha−1 and 120 kg ha−1 respectively. In 2023, the application amounts of HA, M, and V were 60 kg ha−1, 120 kg ha−1, and 120 kg ha−1. It should be pointed out that V contains HA in the range of 20–35%. This study aimed to explore the improvement effect of a single or combined application of HA, M, and V on soil quality and cotton emergence rate using dry sowing and wet emergence technology in Xinjiang cotton fields. The results showed that the single and combined applications of HA, M, and V improved the soil quality and water–heat–salt environment of the cultivated layer. In the combined application, the cotton seedling emergence rate and yield increased by 1.9–22.8% and 7.0–54.1%. Therefore, it is recommended to jointly apply HA, M, and V to promote cotton seedling emergence and increase yield using dry sowing and wet emergence technology in Xinjiang cotton fields.

Heat Dissipation Capability of Stagger-Stacked Double Data Rate Module

In this study, we introduce a stagger-stacked DDR module that comprises one IPD chip (top die) along with four memory chips initially. The steady-state thermal characteristics of this configuration were empirically assessed using a dedicated thermal test vehicle. The purpose of this research is to investigate the module’s junction temperature by adjusting four factors: the thermal conductivity of the molding plastic, chip thickness, chip misalignment length, and the thermal conductivity of the adhesive film. We observed that the junction temperature decreases with an increase in the chip staggered length. An improved orthogonal experimental method was utilized to achieve the optimal design of the module. The optimal junction temperature has decreased by 4.74% compared to the initial value. Additionally, three alternative packaging technologies—cantilever, pyramid, and a combination of cantilever and pyramid—were evaluated for the benchmarking of the thermal performance. Ultimately, the stagger-stacked package demonstrated a reduction in the junction temperature by 3.62%, 7.95%, and 5.63%, respectively, when compared to the three traditional stacked packages.

Numerical analysis and process optimization of electron beam melting for superalloys

This study aims to determine the optimal parameters for the electron beam melting process by employing a modified transient three-dimensional thermal model. The validity of the thermal model is confirmed through experimental results. Moreover, the proposed method establishes mathematical relationships between the resulting molten pool temperature and process parameters. A broader range of process parameters for a new Ni–Co-based superalloy was achieved by investigating the effects of scanning velocities (10–100 mm/s), scanning radius (20–60 mm), and melting mass (1500–3100 g) on temperature at various electron beam power levels (10–30 kW). Regression models were established between scanning velocities-temperature, and scanning radius-temperature under different electron beam power levels. These models laid the foundation for real-time automatic control of molten pool temperature. Significantly, orthogonal experimental design and response surface method are employed to conduct a multi-objective optimization based on sixteen experiments and three parameters. The results of multi-objective optimization indicate that with a smelting mass of 1.5 kg, an electron beam power of 11 kW, a scanning radius of 60 mm, and a scanning velocity of 75 mm/s, the energy consumption is 34.95 kW h, and the theoretical mass loss of Ni element is 0.002 kg. The desirability is 91.2 %.

Research on optimal design method of dynamic stress parameters of helical gear based on orthogonal experimental design

Aiming at the reliability optimization design problem of two-grade helical cylindrical gear transmission system, the UG parameterized model based on expression and ADAMS dynamic simulation model under real working conditions are integrated in ISIGHT platform, and the distribution law of peak contact force on the tooth surface of helical gear pair in the transmission system at different meshing times is obtained. Considering the uncertainty of material properties, load conditions and geometric parameters, the sample set was generated according to the orthogonal experimental design method, and the Kriging approximation model was established. On this basis, the contact strength reliability of helical gear was analyzed. The mathematical model of meshing efficiency reliability optimization of helical gear pair was established and solved by Hooke-Jeeves Direct Search method. The results show that the meshing efficiency and reliability of the optimized helical gear pair are improved, and the peak value of the contact force is obviously reduced.

Effect of parameter optimization on the flow characteristics of venturi-self-excited oscillation mixer based on response surface model and multi-island genetic algorithm

Effect of parameter optimization on the flow characteristics of venturi-self-excited oscillation mixer based on response surface model and multi-island genetic algorithm

Optimization of mechanical properties for intelligent building materials combining with various steel fiber types and nano-Carbon black

The mechanical properties of building materials has emerged as a novel application criterion. However, the investigation of the influence of different steel fibers (SFs) types and nano-carbon black (CB) on the mechanical properties of intelligent building materials remains limited. In this paper, an orthogonal test is conducted to analyze the mechanical performance of building materials with various types of SF and different factors of SFs and CB content. The single-phase results reveal that the optimal content of SFs for intelligent building materials ranges from 0.20%∼0.80% when combined with air content and mechanical performance indicators, while the CB content range ranges from 0.25 wt%∼0.75 wt%. Additionally, the study employs the orthogonal experimental method to determine the mix proportion for intelligent building materials. The experiment selected orthogonal design conditions with four levels and three factors (including SF types and contents and CB content) and conducts range analysis and variance analysis on the experimental results of each group. The results demonstrate that the compressive strength and splitting tensile strength of building materials are optimized when the contents of shear-type SFs and CB are 0.40% and 0.75 wt%, respectively.

Preparation and properties of phenolic foam modified with boric acid and organosiloxane by supercritical CO2 technology

AbstractIn this study, a silica boron modified phenolic resin foam (SiBPF) is prepared in a reactor under specific pressure and temperature and using supercritical CO2 (scCO2) as a physical foaming agent, to improve phenolic foam (PF) brittle and friable properties and avoid environmental pollution caused by conventional physical foaming. To determine the partially curing degree for foaming, the influence of partially curing time at partially curing degrees between 39.88% and 53.17% was studied. Further, through an orthogonal experimental method, the optimized foaming process parameters—partially curing time of 6 h, adsorption time of 9 h, foaming pressure of 1 MPa, and foaming temperature of 130°C—were determined. The SiBPF, thus prepared under the optimized conditions, exhibited a density of 0.2356 g/cm3, an average cell size of 86.66 μm, and a cell density of 7.10 × 106 cells/cm3. Its compressive strength was found to be 7.28 MPa, with a specific compressive strength of 30.90 MPa/g·cm−3. At 800°C, the carbon residue rate, thermal decomposition temperature T5%, and Tmax reached 77.61%, 355.21, and 702.70°C, respectively. The thermal conductivity of SiBPF was measured to be 0.0644 W/mK, with the rear temperature stabilizing at 60°C on a hot platform of 100°C.

Proportioning optimization of transparent rock-like specimens with different fracture structures

Clarifying the principles of proportioning optimization for brittle transparent rock-like specimens with differential fracture structures is crucial for the visualization study of the internal fracture and seepage evolution mechanisms in rock masses. This study, utilizing orthogonal experimental methods, uncovers the influence mechanisms, extents, and patterns by which the ratios of resin, hardener, and accelerator, along with the freezing duration, impact the mechanical characteristics of transparent rock-like specimens. Notably, it was observed that as the accelerator ratio and freezing time are increased, there’s a general decline in the uniaxial compressive strength, tensile strength, and elastic modulus of the specimens. In contrast, an increase in the hardener ratio initially leads to an enhancement in these mechanical properties, followed by a subsequent decrease. Under uniaxial compressive loading, the specimens exhibit four typical modes of failure: bursting failure, splitting failure, single inclined plane failure, and bulging failure. As the hardener and accelerator ratios increase, the mode of failure gradually shifts from bulging to bursting, with freezing time having a minor overall impact on the evolution of failure modes. The study proposes a method for inducing random three-dimensional closed fractures within the specimens and further clarifies the principles for optimizing the proportions of specimens with different fracture structures, such as intact, embedded regular, and random three-dimensional fractures. This research facilitates the in-depth application of transparent rock-like materials in various scenarios and provides theoretical guidance and technical support for visualizing the evolution of fracture and seepage characteristics within the fractured rock mass.

Development and performance evaluation of a novel anti-friction agent for H-beam extraction in soil mixing walls

This study focuses on the development and assessment of an innovative anti-friction agent designed to reduce the extraction force required for H-beams in Soil Mixing Walls (SMW). The composition of the new formula for the anti-friction agent was determined using orthogonal experimental methods: vaseline (25 g), paraffin (300 g), rosin (65 g), polytetrafluoroethylene powder (9.75 g), ZDDP (10 g), benzoic acid (4 g), ammonium polyphosphate (2 g), alcohol ester-12 (1.5 g), and theaflavin (1.5 g). Performance evaluation of the new anti-friction agent is carried out through indoor model tests, on-site tests, and indoor bending experiments. The results indicate that compared to commonly used anti-wear agents in the field (Nanjing site anti-friction agent, Guangzhou site anti-wear agent), the new anti-wear agent can significantly reduce friction, by 16.4 % and 14.2 % respectively. The new material has little impact on the bending performance of composite structures before cement-soil failure, in contrast to the Nanjing anti-friction agent typically used in field applications. During on-site applications, if the H-beam coated with conventional anti-friction agent cannot be pulled out while the H-beamcoated with the new anti-friction agent can, then the cost of piles treated with the new anti-friction agent is reduced by 97 %. If both types of steel coated with anti-friction agents can be pulled out, then the cost of piles treated with the new anti-friction agent increases by 0.9 %.

Radiative cooling performance analysis of cooling wood with three delignification processes for building applications

The delignification process is essential in the preparation of radiative cooling wood, and optimizing the delignification process is crucial for achieving a balance in the optical, mechanical, and thermal insulation characteristics of the delignify wood. Using the orthogonal experimental method, the study explored the influence of different delignification processes (such as chlorite, sulfite, and hydrogen peroxide methods), treatment duration, temperature, and other factors on wood weight loss rate, infrared spectroscopy, tensile and flexural strength, thermal conductivity, reflectance, and emissivity in order to obtain the best delignification process parameters for preparing radiative cooling wood with the optimal overall performance. The experimental results showed that delignification treatment followed by hot pressing improved the mechanical properties of the wood. As the delignification temperature and duration increased, the wood weight loss rate also increased, the mechanical properties declined, and the thermal insulating properties improved. The comprehensive comparison revealed that using the hydrogen peroxide method with treatment temperature at 80 °C and lasting 4 h can achieve the best overall performance for radiative cooling wood. Compared with Balsa wood, the tensile strength increased by 4.2 times and the flexural strength by 2.3 times, while the thermal conductivity reached 0.08 W/mK. In outdoor experiments, this radiative cooling wood can attain a good cooling effect throughout the day. During the noon hours, its surface temperature was lower than that of cement and the ambient temperature by 11.4℃ and 4.4℃ respectively, and the net radiative cooling power was up to 46 W/m2. The results show broad prospects for its application in building insulation and energy saving.

Novel hybrid chemical magnetorheological fluid for polishing Ti–6Al–4V alloy

ABSTRACT This study presents a highly efficient chemical and magnetorheological fluid (C-MRF) hybrid polishing process established by using an eco-friendly slurry of malic acid, Fe3O4–SiO2 abrasive particles, and hydrogen peroxide (H2O2) as an oxidant, all mixed with purified water, highlighting its efficacy in a wide range of polishing applications. Herein, the polishing processes of Ti–6Al–4V alloy utilizing C-MRF with on Fe3O4–SiO2 abrasives are detailed, and the polishing performance is assessed by investigating the influence of oxidizing agent H2O2 and acid malic to the surface finish of the Ti–6Al–4V alloy. The linear variable magnetic field by improved Halbach array was proposed to improve the material removal rate and surface quality and create a polishing process with a highly efficient magnetic field source. Single-factor and orthogonal experimental analysis methods are applied to provide the technological parameters factors with varying influences on surface quality and material removal ability.

Conversion of CO2 into fibrous carbon materials using Ga-based liquid alloys

This study investigates the catalytic reduction of CO2 using various ratios of Ga-based liquid alloys under different conditions. We explored the alloying of liquid gallium with metals like indium (In) and magnesium (Mg) through mechanical stirring and heating. The alloys, once prepared, were exposed to CO2 in a reactor, with the Ga-In-Mg alloy demonstrating optimal reaction effects. In an exemplary synthesis, 1 g of Ga was combined with 30 wt% In and 7 wt% Mg, yielding a 7 wt% Ga-In-Mg alloy. This alloy, when reacted with CO2 for 10 h, exhibited a maximum weight gain of 445 mg. Elemental analysis showed a carbon content increase from 4.56 % to 72.56 % post-reaction. The reacted alloy, post-acid washing and electron microscopy examination, revealed the production of fibrous carbon materials approximately 7 μm wide. The primary objectives of this research were to identify the optimal temperature for CO2 reduction by the alloy and to determine the most efficient alloy catalyst using orthogonal experimental methods. Furthermore, we aimed to elucidate the catalytic mechanism of gallium-based liquid metal in CO2 reduction. The study also involved analyzing the adsorption and reaction processes by fitting the adsorption and reaction kinetic curves of the liquid metal with CO2. Achieving these objectives could enable the conversion of CO2 into solid carbon products, aligning with current environmental and sustainable development goals. This research offers new insights and innovative approaches to tackling energy-related challenges, highlighting the potential of liquid metal alloys in carbon capture and reduction applications.

Analysis and optimization of stamping and forming process of bearing outer ring

To address the common issues of wrinkling, tearing, and uneven wall thickness in the actual sheet metal stamping process of the outer ring of needle roller bearings, this study analyzes critical technical indicators such as forming limits, thickness distribution, and principal strains in the forming process in detail. Three-dimensional models of the concave and convex dies were constructed. The effects of different process parameters, including stamping speed, edge pressure, sheet metal thickness, and friction coefficient, on the quality of the forming parts were investigated by varying these parameters. Subsequently, the orthogonal experimental method was used to determine an optimal experimental group from multiple sets of experiments. It was found that under the process parameters of a stamping speed of 3000 mm/s, edge pressure of 2000 N, sheet metal thickness of 0.9 mm, and friction coefficient of 0.125, the forming quality of the outer ring of the bearing is ideal.

Effect of Floating Support Parameters on the Load-Sharing Performance of EDPGS Based on Mathematical Statistical Methods

The encased differential planetary gear system (EDPGS) allows power to be distributed among multiple output paths, enhancing efficiency and reducing weight. Uniform load distribution ensures stable system operation and prolongs service life. However, stochastic manufacturing errors leading to uneven load distribution pose challenges in engineering practice. To investigate the impact of floating support parameters on the load-sharing performance within an acceptable tolerance band, a dynamic model of the EDPGS considering time-varying meshing stiffness and random errors is established using the Monte Carlo method. This study employs the orthogonal experimental design method to analyze the effects of floating support stiffness and clearance on the load-sharing characteristics. The findings indicate that a larger sample size leads to a probability distribution of load-sharing coefficients closer to the Gaussian distribution, with minimal influence on the expectation and variance. Furthermore, this study highlights the significant influence of floating structure parameters on load-sharing characteristics in the encased stage systems compared to the differential stage. Decreasing floating support stiffness or increasing floating clearance proves beneficial in enhancing the load-sharing performance of the system.

Microstructure and Wear Performance of High-Velocity Arc Sprayed FeMnCrNiBNbAl Coating

In this study, FeMnCrNiBNbAl wear-resistant coatings were prepared via high-velocity arc spraying technology on the surface of Q235 steel. The effects of spraying distance, voltage, and current on the coating performance were studied via the orthogonal experimental method with microhardness and porosity as evaluation indicators, and the process parameters were optimized. The order of primary and secondary factors affecting coating performance were: spraying distance, voltage, and current. The optimized process parameters are: spraying distance 200 mm, voltage 36 V, and current 240 A. The coating prepared using the optimized process parameters has an average microhardness of 756 HV0.1 and an average porosity of 1.03%. The coating mainly consists of α-Fe, Fe-Cr, Ni-Cr-Fe, Al2O3, and (Fe, Ni) solid solution. The coating friction coefficient was 0.5 while that of the substrate was 0.7. The depth and width of the wear marks of the coating were 6.32 µm and 555.41 µm, respectively, which are 66% and 32% lower in comparison with Q235 steel under the same test conditions. The wear forms of this coating were mainly fatigue peeling and adhesive wear.

Annual performance study and optimization of concentrated photovoltaic-phase change material system

Concentrated photovoltaic (CPV) has the superiority of high efficiency and low cost. But the waste heat generated in PV cell has great effect on its performance. To study and optimize the real time photoelectric conversion performance, a two-dimensional PV model was firstly established. The impacts of concentration ratio and PV temperature on efficiency were investigated, and the correlation was derived. Based on that, phase change material (PCM) was utilized to realize temperature control of PV cell and a three-dimensional transient model for CPV-PCM system was established. The impacts of geometric parameters on the transient and annual performance were evaluated under the real climate conditions. The results show that concentration ratio has significant impacts on both thermal and electrical performance, and there exists an optimal concentration ratio to maximize the PV efficiency. At last, the system structure was optimized by orthogonal experimental method with annual average efficiency as the target. The optimal parameters combination was derived with concentration ratio of 300, PCM layer height of 60 mm, and fin number of 7. The validation results show that after optimizing, the maximum PV temperatures in summer and autumn are reduced by 9.4 °C and 7.4 °C, respectively, and the annual average efficiency of the system is improved by 1.83%.