Longitudinal Layout Research Articles

Comparison on thermal and hydraulic performances of transverse mini-channel based on a novel comprehensive evaluation factor

To disclose the application value of cold plate with transverse layout used in thermal management system, a novel dimensionless factor, Comprehensive Index of Thermal Management System (CITMS), is proposed, which involves three most important parameters: pumping power Etol, temperature dispersion Tσ and maximum temperature Tmax. Results show that compared to 15 types of mini-channels (longitudinal parallel, serpentine, bifurcated, u-turn, annular, zigzag, cobweb, elm leaf, diverged, rhombus spoiler, gridding, wave, honeycomb, multistage tesla-valve, pease types), transverse parallel mini-channel shows superior CITMS, which declines by an average of 80.26 % to 99.61 % under weighting coefficient w = 1 and expected operating temperature Texp = 320.15 K. Meanwhile, zigzag, wave, pease and multistage tesla-valve mini-channels with transverse layout show significantly better CITMS than longitudinal layout, which decline by an average of 78.61 % to 89.03 %. This is mainly due to the decline in Tσ and Etol. Furthermore, based on CITMS, an appropriate mass flow rate can be achieved for a specific cold plate. Under w = 30 and Texp = 298.15 K, the optimal value of CITMS for transverse parallel mini-channel occurs at 0.5 g/s. In view of better comprehensive performance and same process difficulty, transverse layout could undoubtedly become an effective design concept.

Novel Skin-Reinforcement Design by Cross–Longitudinal Layout Inspired by Dragonfly Wing

The objective of this study is to develop a novel aircraft design approach using biomimetics as an alternative to traditional airframes. This approach is primarily inspired by the dragonfly wing, which possesses reinforcement structures composed of cross veins and longitudinal veins. These structures are assumed to regulate deformation and enhance stiffness, respectively. The cross veins were replicated using weighted centroidal Voronoi tessellation (WCVT) based on the out-of-plane displacement of the skin. In contrast, the longitudinal veins were replicated by extracting a centerline from the topology optimization (TO) results on the skin, achieved through image analysis techniques such as binarization and skeletonization. The longitudinal layout effectively reduces compliance by distributing internal loads, utilizing only essential reinforcements on the skin without increasing its mass. The WCVT layout significantly enhances the buckling resistance of the reinforced skin. As a result, the skin reinforced using both cross–longitudinal layouts from TO and WCVT exhibited a buckling load 2.7 times greater while maintaining a lower mass compared to conventional layouts.

Research on Calculation Method for Discharge Capacity of Draining Well in Tailing Ponds Based on “Simplification-Fitting” Method

The existing empirical formulas concerning draining systems are complex in their expression: there are difficulties in locating the intersection point among different flow patterns and parameters vary depending on the water level, resulting in a large amount of data to be processed and low calculation efficiency. To solve these problems, a “simplification-fitting” method was proposed herein to calculate the discharge capacity of a window-type draining well, and optimal and reasonable locations were selected as discrete points of water level to deduce the increasing progressive relationship of free flow discharge capacity among discrete points according to the window size and longitudinal layout of window-type draining wells. Additionally, the algorithm simplified the discharge formulas of half-pressure flow and pressure flow and defined the convergence criteria for water level-discharge capacity to further simplify the expression of pressure flow. The comparison and contrast between the simplified calculation method and empirical formula method show that the method herein is of high precision. It is able to resolve the shortcomings of the traditional theoretical formula method in solving the discharge capacity curve of a window-type draining well and simplify the algorithm integration.

A non-uniform strip-array decoupling structure of the MIMO antenna-arrays for the DSRC application

ABSTRACT In this paper, a non-uniform strip-array decoupling structure (SADS) of the MIMO antenna-arrays for the dedicated short-range communication (DSRC) applications in intelligent transportation systems (ITS) is presented. The SADS is composed of metal strips with non-uniform longitudinal layout, which has a simple strip-array geometry, low design and fabrication complexity, and easy to be applied to the design domain without destroying the original antenna-array. The design of the strip thickness, strip-array layout and number of strips is realised by the proposed simple and effective optimisation method. The mutual coupling between the elements can be effectively suppressed to less than −32 dB by the proposed structure in the required bandwidth (5.795 GHz~5.815 GHz). The results show that, compared with the no-strip and uniform SADS, the non-uniform SADS can improve the maximum mutual coupling reduction by 23 dB and 13 dB, respectively. Both the simulated and measured results verify the effectiveness of the proposed SADS, which makes it very suitable for the large-scale MIMO antenna-arrays.

Optimal construction method and demonstration application of multi-in-one station grounding system

Mutual influence may be driven by different models and operating mechanisms of grounding systems in multi-in- one substations. Even equipment damage and personal injury will occur in the event of a short-circuit or lightning strike. To meet the construction requirements of different multi-in-one substations, two typical application modes of grounding systems in multi-in-one substations are analyzed in this paper: plane and longitudinal layout schemes. First, the safety index and withstand voltage of secondary equipment in multi-in-one substations are introduced. Second, the plane layout scheme of grounding grids is examined. Based on a 35-kV multi-in-one substations in Shanghai, it was verified that the overall grounding grid needs to be laid to meet the safety of secondary equipment in the station. Finally, considering that it is feasible to rebuild the upper layer of a substation, the longitudinal layout scheme of the grounding grid in multi-in-one substations is also examined. Safety assessment is carried out in terms of aspects such as short-circuits and lightning strikes, and relevant optimization construction methods are analyzed. In this study, a real 35-kV substation in Shanghai was selected as an example. Simulation and field tests based on Current Distribution, Electromagnetic Fields, Grounding and Soil Structure Analysis (CDEGS) software verified that the proposed construction scheme can achieve safe operation of multi-in-one substations. This construction idea can also serve as a reference for the future construction of multi-in-one substations.

Fault tolerant control of uav with wing layout based on control allocation

As the flying wing layout unmanned aerial vehicle (uav) extensive research and task environment increasingly complex, Yu Feiyi layout unmanned aerial vehicle (uav) for fault tolerant control gradually become the main technical means of the flight control, using the established mathematical model of the flying wing uav longitudinal layout setting the actuator failure effect, is in the nature of adaptive control allocation fault-tolerant algorithm is given, and MATLAB/simulink simulation is carried out for uav longitudinal motion, realize the rapid and stable, the control command and response to complete the nonlinear fault-tolerant control of flying wing uavs.

Numerical analysis on heat-flow-coupled temperature field for orthogonal face gears with oil–jet lubrication

Lubrication and cooling performances of face gears with oil–jet lubrication are closely related to the nozzle layouts. To investigate the influence of the nozzle layouts on the lubrication performance of the face gears, a numerical analysis method based on heat-flow coupling is adopted in this study for predicting the transient temperature characteristics. First, a mathematical model of impingement depth integrating the nozzle spatial layouts, injection parameters, and geometric parameters of the given face gear is presented for determining the nozzle. Then, after accessing the friction heat, the heat-flow-coupled finite element model is built to resemble the oil–jet lubrication process and obtain the temperature field on the tooth surface. Finally, under the same nozzle layouts, the temperature distributions are compared with the oil pressure and oil volume fraction reported in previous studies. The results reveal that the nozzle layouts significantly affect lubrication performance. Specifically, the lubrication performance of the lateral layout parameter near the middle point of the tooth width is better, and there is a certain range for the longitudinal layout parameter and jet elevation angle. This study can provide a reference for further optimizing the nozzle layouts and prolonging the service life of the orthogonal face gear.

Design and construction of post-tensioned concrete box-girder viaducts for high-speed rail

This paper explains the design criteria used for nine box-girder continuous high-speed rail viaducts constructed in Spain. It describes the longitudinal layout and an innovative construction process using movable scaffolding. A comparison between different post-tensioning and reinforcing steel ratios is provided. Recommendations for fatigue design and concrete stress criteria in the serviceability limit state are given. In addition, the paper provides the quantities of concrete, post-tensioning and reinforcing steel used in the construction of the viaducts.

Abstract 763: Understanding of cancer clinical trial data and statistical opportunities

Abstract Purpose: The study aims to discuss various types of cancer clinical trial data with potential statistical solutions. Background: Cancer clinical trial allows researchers discovering new strategies to prevent, detect, diagnose, or treat cancer. Each trial collects many types of patient data to evaluate various treatment characteristics, such as tumor response data, adverse event (AE) data, demographic data, and follow-up data. Each data type is often stored in a multi-dimensional and irregularly longitudinal layout with potential hierarchical structure, therefore generating ‘big data' phenomena. Such complexities often scare away researchers and lead to use naïve descriptive statistics for analysis. As a result, it loses valuable information and becomes a major hurdle to advance cancer precision medicine. Here we share our thoughts for two primary data types: tumor response data and safety data. Tumor Response Data: Tumor response data is a key component to evaluate treatment efficacy in clinical trial for solid tumor. Response Evaluation Criteria for Solid Tumors (RECIST) has been a standard tool to assess treatment effect. RECIST measures three types of lesion to determine treatment efficacy: target lesion, non-target lesion, and new lesion. Target lesion is the primary lesion to determine response (tumor shrinkage), progression (tumor outgrowth), or stable disease. However, studies have raised issues regarding RECIST being applied for incorrect determination of response, which resulted in premature termination of therapy and imprecise efficacy. One key limitation of RECIST is the use of sum of all target lesion sizes for clinical decision-making. While this approach is straightforward for calculation, it fails to address lesion variability of tumor growth in an individual patient. Statistical mixed effect model could be a powerful tool to fully utilize all lesion data to provide overall assessment of treatment effect and individual lesion variability. Safety Data: Safety data is a critical component of clinical trial to protect patients from unnecessary risk and to develop safety profile of the drug for benefit-risk assessment. The safety data contains many types of AE to monitoring drug toxicity. Evaluation metrics include grade, duration, and likelihood of the treatment attribution; therefore it forms a giant complicated structure. However, safety report in clinical trials is often presented in summary descriptive statistics, such as yes/no of occurrence or frequency of occurrence for each AE. This type of report has been challenged due to inadequate information or lack of details. Statistical opportunities include integration of various safety metrics to generate more useful toxicity variables, such as AE duration adjusted with different grade. Conclusion: Clinical trial collects valuable big data and statistical methods have potential to transform the rich but complicated data into informative evidence. Citation Format: Dung-Tsa Chen, Ben Creelan, Trevor Rose, Wenyaw Chan. Understanding of cancer clinical trial data and statistical opportunities [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 763.

Development and laboratory evaluation of a self-monitoring polymer geobelts

Due to the rise of smart city construction in recent years, there is a growing demand for materials that can both improve the mechanical properties of structures and carry out health monitoring and risk warning. In this paper, a self-monitoring polymer geobelt manufactured by 3D printing technology is proposed, which can embed conductive ABS material directly into non-conductive PLA material as conductive wire. This integrated resistance geobelt solves the problem of sensor contact to the outside of the grid and water which is easy to fall off and the test results are inaccurate. In this study, a series of tests were performed to study the development and laboratory evaluation of a tensoresistivity geobelts and conclusions were drawn as follows: The self-monitoring polymer geobelt made with PLA and conductive ABS showed good self-perception characteristics and recoverability, and the more the number of longitudinal layout of internal conductive wires, the more accurate the results showed. The relationship between resistance and tensile stress after normalized at ends of the geobelt can be fitted by parabola f = A + Br + Cr2, and the strain of smart geobelt ranges from 2.1 to 10%.

Алгоритмы работы и схема построения гироинклинометра с продольной компоновкой для вертикальных участков стволов

Алгоритмы работы и схема построения гироинклинометра с продольной компоновкой для вертикальных участков стволов

A Note on Baffle Orientation in Long Ponds

This paper assesses the general idea of implementing transversal baffles to improve hydraulic efficiency of rectangular ponds used in water and wastewater treatment processes. The paper concentrates on long ponds with the length-to-width ratio of 4:1. Three different scenarios of plain (baffle-less) pond and ponds with four transversal and two longitudinal baffles were considered. A two dimensional Computational Fluid Dynamics (CFD) conservative tracer study was performed. Results showed that the longitudinal layout of the baffles yielded to a hydraulic regime closer to the plug-flow condition, while application of limited number of transverse baffles in long ponds showed an adverse effect on the overall hydraulic performance. Such baffles layout yielded to increased dispersion, as well as comparable dead zones in comparison with the plain pond. A three dimensional analysis was also conducted to evaluate the effect of volumetric dispersion, which yielded to the same results. Possible reasons for this phenomenon were discussed. Results suggest that application of limited number of transverse baffles in long ponds needs extra consideration.

The longitudinal layout alternate version of cogeneration steam turbines with the generator placed on the side of the high-pressure cylinder

The schematic design of a cogeneration steam turbine with the generator placed on the side of the high-pressure cylinder is proposed. It is shown that the use of this solution is most promising for turbines with a longitudinal layout (like a T-175/210-12.8 turbine).

Design and construction experiences of multi-stage flash evaporator module train for 4500 m3/day MSF plant coupled to nuclear power plant at Kalpakkam

The fl ash evaporator modules are the core installations of any MSF Desalination plant. These are normally rectangular modules consisting of brine fl ash chambers and vapour condensers generally mounted at high elevations based on NPSH considerations of brine re-circulation pumps. BARC has recently constructed a 4500 m3/day MSF Desalination plant coupled to 235 MWe nuclear reactor at Kalpakkam in the southern region of India. The plant consists of 39 nos of fl ash evaporation stages distributed among 10 nos of large fl ash evaporator modules of different sizes, arranged in a longitudinal layout (long tube design). The smallest of these modules has internal dimensions 2.20 m width, 2.95 m height and 11.30 m length and the largest module is 3.10 m wide, 3.50 m high and 16.30 m long. Major materials of construction include carbon steel, stainless steel, cupro-nickel and inconel. The rectangular geometry, massive size, number of internal compartments, built in condenser, the corrosive seawater environment, etc. make the design and construction of these modules different from conventional process equipments. In this paper, mechanical design and construction experiences of these modules are described covering design and construction features of the modules, construction methodologies adopted, its qualifi cations, problems faced during construction, etc.

High-order bending of piecewise uniform sandwich beams with a tapered transition zone and a transversely flexible core

High-order bending of a piecewise uniform sandwich beam with a tapered transition zone and a transversely flexible core is presented. The behavior is described through the solutions of a uniform and a tapered sandwich beam in the various regions, interconnected while fulfilling the boundary and the continuity conditions between the regions. The longitudinal and the shear forces in the inclined skin of the tapered region yield concentrated forces at the point where the skin longitudinal layout changes, thus leading to stress concentrations in the form of high peeling and shear stresss at the interface between the skin and core, and to high local bending moment in the skin. This stress concentration emerges whether the external loads are concentrated or distributed and is an inherent part of the structure. However, the level of stresses involved can be controlled through the appropriate design of the transition zone. The characteristic behavior in the transition zone and the design parameters that affect the behavior, are studied through a parametric analysis. The fields and the governing equations of a tapered beam are presented, and the results of the parametric study in terms of shear forces and bending moments in the lower skin and shear and peeling stresses at the lower skin-core interfaces, are presented and discussed.