Bench Design Research Articles

Development of a Robust Test Rig for Tilting Pad Journal Bearing Validation

Several theoretical models for predicting the performance of tilting pad journal bearings (TPJB) have been developed by the scientific community over the years. However, reliable validation of the predictions based on the theoretical models, taking into account the complexity of TPJBs, demands robustness in the design and assembly of an improved test rig. Test bench designs for testing hydrodynamic bearings must carefully consider construction details as much as possible to observe the effect from the journal bearing and, consequently, improve the predictability of its dynamical behavior. In this context, there are still relatively few test rigs in the specific literature devoted to isolating the dynamic effects from hydrodynamic bearings for analysis purposes. Therefore, a novel test rig project is described in this work, also involving the design versatility characterized by measurement feasibility in rolling-element bearings and fixed-geometry, hydrodynamic journal bearings. This test rig aims to reproduce the most diverse operating conditions in order to measure the involved physical responses and validate the different models applied to the bearings. Therefore, the bearing performance can be properly evaluated, especially when operating under critical operating conditions, thus providing important contributions to the area of lubrication and rotor dynamics.

Experimental verification of predicted capability of a wind turbine drivetrain test bench to replicate dynamic loads onto multi-megawatt nacelles

A total of 27 test profiles from the IEC 61400-1 design load cases were tested using a 7.5-MW wind turbine drivetrain test bench and two multi-megawatt wind turbine drivetrains. Each test profile consisted of simultaneous vertical, lateral, and longitudinal forces, yawing and nodding bending moment, and rotational speed. These test-bench inputs were compared with the forces, bending moments, and speed that were applied to the wind turbine drivetrains to quantify the test-bench tracking error. This tracking error was quantified for a range of ramp-rate limits of the yawing and nodding bending moments. The experimental results were compared with predictions from an evaluation method for the capability of wind turbine drivetrain test benches to replicate dynamic loads. The method’s predictive capability was found to be sufficient for the goal of early screening and its formulation is applicable to any wind turbine drivetrain test bench and drivetrain design.

Justification of the parameters of rotary-vibration drilling of small-diameter boreholes in rocks based on a submersible cavitation hydrovibrator

The article presents the results of laboratory studies of the rotary-vibration drilling method of blast-holes and boreholes of small diameter based on a submersible cavitation hydro-vibrator. A generator that operates in the mode of intermittently stalled cavitation was used as a source of vibration load to the rock-breaking tool. The authors of this article developed and described the design of a submersible cavitation hydro-vibrator at the level of the patent of Ukraine for the invention. In addition, a bench design for laboratory studies of the parameters of a rotary-vibration drilling method was developed and described at the level of a patent of Ukraine for a utility model. It is established that the optimal mode of operation of the cavitation generator is ensured by its cavitation parameter in the range of 0.16-0.2. The geometrical parameters of the cavitation generator in the submersible cavitation hydro-vibrator are determined: the diameter of the critical section is 2.0 mm, the opening angle of the diffuser is 20º, and the outlet diameter is 10.0 mm, and the length of the post-diffuser channel is 200 mm. It is established that under the action of pressure pulses of the washing liquid, which is passed through the cavitation vibrator in the optimal mode, the additional deepening of the rock-breaking tool into the rock sample reaches up to 0.6 mm per rotation. Thus, the drilling speed of small-diameter blast-holes and boreholes (up to 55 mm) with the ЕБГП‑1М drilling rig of the Konotop Machine-Building Plant with the optimal mode of the rotation frequency of the rock-breaking tool, which equals 315 min-1 (5.25 s-1), can be increased by 3∙10-3 m/s, from 23∙10-3 m/s up to 26∙10-3 m/s, which is 13%. Keywords: the rotary-vibration drilling method, cavitation generator, submersible cavitation hydro-vibrator, mining rock.

Reduced-scale experimental bench design of high-pressure blowing system of submersible

Objectives To supply experimental platform for manufacturing of submersible high-pressure blowing system (HPBS), Methods based on isentropic blowing model of Laval spray and Bernoulli equations, mathematical modellings of high-pressure blowing and draining off had been accomplished. Method Based on similarity theory, a HPBS reduced-scale experimental bench of Strouhal and Euler similarity had been designed, including pressure vessel prototype of ballast tank and sea tank. Results Under different initial conditions, including back-pressures of 300, 200 and 100 m, flowing areas of 100%, 75%, 50%, and blowing-pressures of 25, 20, 15 MPa, the maximal pressure of the compressed air in the ballast tank had been beyond the vessel regulation pressure, and the expansion volume of the compressed air in the ballast had been above the vessel regulation cubage, Conclusions which had been proved that the experimental bench can satisfy with performance recurrences of the submersible high-pressure blowing system.

To Play and To Be Played: Exploring the Design of Urban Machines for Playful Placemaking

Within the paradigm of the smart and playable city, the urban landscape and street furniture have provided a fertile platform for pragmatic and hedonic goals of urban liveability through technology augmentation. Smart street furniture has grown from being a novelty to become a common sight in metropolitan cities, co-opted for improving the efficiency of services. However, as we consider technologies that are increasingly smarter, with human-like intelligence, we navigate towards uncharted waters when discussing the consequences of their integration with the urban landscape. The implications of a new genre of street furniture embedded with artificial intelligence, where the machine has autonomy and is an active player itself, are yet to be fully understood. In this article, we analyse the evolving design of public benches along the axes of smartness and disruption to understand their qualities as playful, urban machines in public spaces. We present a concept-driven speculative design case study, as an exploration of a smart, sensing, and disruptive urban machine for playful placemaking. With the emergence of artificial intelligence, we expand on the potential of urban machines to partake an increasingly active role as co-creators of play and playful placemaking in the cities of tomorrow.

Optimum Open Pit Design for Kenticha Tantalite Mine, Southern Ethiopia

The mining sector’s share in Ethiopia’s economy is gradually increasing. Among metallic mines, Legadembi for gold and Kenticha for tantalum are the main contributors. At Kenticha, the Ethiopian Mineral Development Share Company is producing tantalite concentrate of 40-60% grade by open pit mining. The mine area is comprised of the rocks of Neoproterozoic age, pegmatite, granite, serpentinite, and talc-chlorite schist. The ore-bearing pegmatite intruding the basement serpentinite, and talc schist rocks, is asymmetric, N-S trending, and locally affected by fractures and local faults. Mining, at present, is being done using conventional methods not by developing benches. An optimum open pit design is developed and its impact on the run of mine is evaluated based on the field data, technical mine report data, borehole data, tonnage data, grade data, and mine survey. The suggested design has taken into account the mine drainage, bench design, haul road design, and mine waste dump design. Also keeping in view the future mining and production requirements. The suggested open pit mine design can minimize the dilution and improve the ore recovery.

Modal analysis and analysis of motor support based on workbench test bench design of motor dynamic shock absorber

This article takes the test bench support (hereinafter referred to as the support) as the research object, analyzes its natural frequency, establishes a three-dimensional model of the support through creo, and uses ansys workbench for modal analysis. The motor is an adjustable-speed motor with a maximum speed of 20000r/s and is fixed on the bracket. The rotation excitation frequency of the motor and the natural frequency of the bracket will form resonance in the first 10 steps, so a damping shock absorber is designed to transfer the vibration on the motor to the vibration reduction device, so as to achieve the purpose of eliminating vibration.

Researching on mathematical computation and experimental bench design of high-pressure blowing system

Utilized in sinking and surfacing of Autonomous Underwater Vehicle(AUV), the high-pressure blowing system(HPBS)had played an important role in maneuvering pilot of AUV and must be investigated thoroughly, by which the reserve buoyancy can be controlled. Because of the costliness of experiment on the real ship, an experimental bench of HPBS had been proposed and designed. After mathematical computations of sinking and surfacing processes of AUV, the pressure vessel prototype and it critical physical parameters selection were accomplished, which were used as ballast tank and sea environmental tank of the HPBS experimental bench. Based on those, the blueprint of the total experimental bench had been drawn and the working course of HPBS had been demonstrated.

ИССЛЕДОВАНИЕ ВИБРОАКТИВНОСТИ ЭЛЕКТРОШПИНДЕЛЕЙ ШЛИФОВАЛЬНЫХ СТАНКОВ

The purpose of this work is to support dynamic properties of spindle units in grinding machines. For this there are problems under solution for the definition of the origin of the constituents in the spindle unit vibratory activity by means of the linear increase of electric spindle rotation frequency, obtaining and analyzing a vibratory acceleration signal for the possibility to determine a preload. The vibratory acceleration signal was investigated through a spectrum analysis method. A scientific novelty of investigation consists in the substantiation of possibility to determine a preload by means of the spectrum analysis of a vibration acceleration signal at the linear increase of spindle rotation frequency that is at starting. It gives, in its turn, a possibility for the automated estimate of the spindle unit state before cutting beginning. In the experimental way there are obtained temporal realizations of the vibratory acceleration signal at different efforts of the preload. A high-speed grinding motor-spindle is as a basic element of the bench, which was investigated through the methods of testing diagnostics in the operation. In the bench design there were made some alterations. The bench was supplemented with the systems essential to support motor-spindle full operation, in particular: with systems of lubrication, cooling and drive control. There was revealed a large number of harmonics multiple to 50 Hz, which tells of the connection with the frequency of power supply circuit. Their coincidence with the own frequencies of the spindle unit results in the considerable increase of their amplitudes. To increase dynamic quality one should avoid the cases of the coincidence of switching frequencies and circuit harmonics with own frequencies of the electric spindle. It is also necessary to bring a form of power voltage to a pure harmonic oscillation to decrease the impact of a drive electromagnetic field upon dynamic characteristics of the spindle unit.

Fast and efficient FPGA implementation of Polar Codes and SoC test bench

In this paper we describe a novel and efficient System on Chip Field Programmable Gate Array (SoC FPGA) implementation and test bench for short Polar Codes on an Intel DE10-Standard Development Kit. Encoder and decoder are synthesized on the FPGA fabric and the whole functionality of a complete test bench is developed with an embedded ARM-based hard processor system. A Very High Speed Integrated Circuit (VHSIC) Hardware Description Language (VHDL) parametric design allows synthesis for different code lengths and is suitable for rate-adaptive decoding schemes. We implement fully-unrolled encoder and decoder architectures to achieve high troughputs and lower energy requirements, and achieve an 11% higher throughput than a reference implementation, for short Polar Codes. A novel Merged Processing Element (MPE) is optimized to be used with Sign–Magnitude LLR (SM LLR) discrete representations and pre-computing results in the decoder to reduce latency and resource consumption in comparison to reference designs. A simplified version of this MPE is also implemented, trading higher latencies for lower resource requirements. The SoC test bench design allows single-board automated testing and is also suitable for other error-correcting schemes. Error-correcting performance is evaluated for different combinations of integer and decimal part bits in LLR quantified representations. Also a new simplified non-statistical LLR metric was tested with promising results.

Durability Test Bench Design for Electric Lock of Sliding Door

With the rapid development of automobile industry, electric door locks have widely used in various vehicle doors, especially for sliding doors. Among all performances, durability performance for electric locks is virtual for safety, so miniaturized durability test bench has been designed in the research according to the national standard of electric lock. Firstly, four-bar linkage mechanism has been adopted as the main actuator for the motion track achievement, the real motion track of sliding door can be guaranteed through the verification of ADAMS simulation. Secondly, the compression test has been carried out to calculate the reaction force of door sealing strips, thus the resistance device of test bench for simulating reliable locking process of electric lock has been designed. The miniaturized durability test bench can replace the existing durability test method which only performed by the whole vehicle testing, thus providing a low-cost and reliable test device for relevant manufacturers.

Development of test bench to determine the distribution of granular fertilizers in planting rows using spiral roller, two spiral rollers and fluted roller

The success of the application of granular fertilizers (GFs) in planting rows depends on the uniformity and performance of product dispensing systems, which are influenced by external factors. The objective of this study was to determine the outflow rates of two GF formulations (GF1 04-14-08 and GF2 04-30-10) using three types of fertilizer spreader-with one spiral roller (A), two spiral rollers (B), or a fluted roller (C)-and three operating speeds (1,11, 1.94, and 2.77 m s-1). The following parameters were determined in GFs: density, angle of repose, water content, and segregation (particle size). In the designed test bench, GFs were transferred from a reservoir to a spreader, and ultimately to a container, where they were weighed, and data were transmitted to the data acquisition system (DAS). A total of 7,560 outflow data points were collected (g s-1) and subjected to descriptive analysis of measures of central tendency, dispersion, asymmetry, and kurtosis, and Shewhart control charts were generated. Particle density and segregation were significantly different between the GFs, whereas the angle of repose and water content were not significantly different. The bench design and the DAS allowed measuring the outflow of GFs in different spreaders and demonstrated that this parameter was influenced by particle segregation. The segregation of GF1 was higher than that of GF2. The outflow variability at the speed of 1.11 m s-1 was lower, and the spreader with a fluted roller had the highest uniformity and was the most suitable for application with variable rates.

FP-TES: A Fluidisation-Based Particle Thermal Energy Storage, Part I: Numerical Investigations and Bulk Heat Conductivity

Renewables should become more continuously available, reliable and cost-efficient to manage the challenges caused by the energy transition. Thus, analytic and numerical investigations for the layout of a pilot plant of a concept called Fluidisation-Based Particle Thermal Energy Storage (FP-TES)—a highly flexible, short- to long-term fluidised bed regenerative heat storage utilising a pressure gradient for hot powder transport, and thus enabling minimal losses, high energy densities, compact construction and countercurrent heat exchange—are presented in this article. Such devices in decentralised set-up—being included in energy- and especially heat-intensive industries, storing latent or sensible heat or power-to-heat to minimise losses and compensate fluctuations—can help to achieve the above-stated goals. Part I of this article is focused on geometrical and fluidic design via numerical investigations utilising Computational Particle Fluid Dynamics (CPFD). In the process a controlled transient simulation method called co-simulation of FP-TES is developed forming the basis for test bench design and execution of further co-simulation. Within this process an advanced design of rotational symmetric hoppers with additional baffles in the heat exchanger (HEX) and internal pipes to stabilise the particle mass flow is developed. Moreover, a contribution bulk heat conductivity is presented to demonstrate low thermal losses and limited needs for thermal insulation by taking into account the thermal insulation of the outer layer of the hopper.

The optimal design of school desks depending on the height and weight of students

Background: The subject of this research is the creation of an optimal school bench design with the aim of determining the most favorable posture of students while sitting, taking into account the relevant ergonometric and biomechanical characteristics of the human body. For the proposed model of the school bench which allows adjusting the different slopes of its surface, the corresponding computer model of the student and the table was first created, and then biomechanical and RULA analysis was performed in order to determine the maximum load in the lumbar part. Next, for each test subject of given weight, it was necessary to determine the amount of maximum load in lumbar zone L3/L4 for different slope angles and to determine the critical angles at which the maximum permissible load of 3400 N is reached.
 Methods: The analysis is performed on a total of 5 subjects of the same height (180 cm) and various weights (60, 70, 80, 90, 100 kg). The task is to determine at which weight and at what angle of the workbench with standard height will not exceed the permissible loads of the spine, specifically referring to the L4/L5 vertebrae whose stresses should not exceed 3400 N. The CATIA software package (Dassault Systèmes, Vélizy-Villacoublay, France) is used for the analysis. By knowing the anthropometric and work environment data with ergonomic design and analysis, the following analyzes were made: biomechanical analysis, rapid upper limb assessment (RULA) and carry analysis (an option from CATIA software).
 Results: The proposed school bench design allows for flexible adjustments to its worktop, that is, changing its tilt. This allows students of different body masses to have an optimal position at work that does not compromise their maximum permissible load in the L4/L5 spinal column (3400N).
 Conclusions: The proposed ergonomic design of the desk will result in students being adequately positioned during their activities at school with the minimal risk of permanent deviations and other health problems.

Do you mind if I smoke here? Exploring the insights that public benches bring to public health research.

In this commentary, we illustrate how exploring the meanings and uses of everyday, seemingly mundane, public objects can advance our understanding of health-related practices and the social norms that shape them. We use the example of the public bench and smoking for this purpose. By observing the design of public benches, the places where they are found, the meanings people attribute to them, and the way people use them, we can learn what health-related practices (e.g., smoking) and who (e.g., people who smoke or who do not smoke) are included and excluded as part of local community life. We thus consider the idea that public benches can be instructive in helping us understand how our health-related practices may be shaped by what can be seen enacted on or from public benches. We ultimately demonstrate how this type of object-based experiential exploration, largely absent from public health research, can provide a novel and insightful perspective to public health research.

Comparative analysis of the possibility to reduce vibration transmission through a pipeline compensator by suppressing dynamic forces and pressure pulsations by active methods

The results of experimental studies of joint two-channel active suppression of pressure surges and vibrations of the working medium to reduce vibration transfer through pipeline compensators of power plants with liquid are considered. No data is available in academic periodicals on the use of active methods to solve this problem. The test bench design with excitation and active damping systems of vibrations and pressure surges is given. Efficiency of more than 15 dB from the use of broadband active systems for damping vibration forces transmitted through the compensator and pressure surges of the working medium inside it, both working separately and together in the frequency range from 10 to 275 Hz has been experimentally obtained. In the narrower frequency ranges from 10 to 350 Hz, active damping up to 25 dB has been obtained.

Optical design for an active standoff spectrometer with a broadband source

We describe an optical bench design that efficiently projects broadband infrared energy from a supercontinuum (SC) source onto an extended target and collects the backscattered return. The optical system enables standoff spectral measurements of surfaces at up to 15 m away with a continuous spectral range from 3.6 to 11 μm. The goal of the optical system is to maximize energy transmission and capture under various fundamental and practical constraints imposed by the SC fiber laser source (broad spectrum, high divergence exiting the fiber), spectrometer (light collimation), detectors (etendue limits), and the overall system (size, weight, and cost). The design effort led to an all-reflective, off-axis configuration for both the transmitter and receiver, using custom-designed enhanced gold surfaces. We are able to successfully capture >90 % of the source energy and transmit it with low loss to the remote target while maintaining a nearly diffraction-limited Gaussian beam. The receiver telescope matches the detector etendue while providing uniform (±2.5 % ) off-axis signal collection over the target area to enable scanning of the SC laser spot.

Time to Reconsider Foot and Leg Position During the Bench Press

ABSTRACT The “feet on the floor” guideline for the bench press is a historical byproduct of old bench designs. The “psoas-relaxed position,” where the hips and knees are flexed and the feet rest on adjustable plates at the end of the bench, should be considered to replace existing guidelines. The psoas-relaxed position accommodates lifters of all body heights, is more sport-specific than current bench press posture, and reduces lumbar lordosis and increases the cross-sectional area of the dural sac and spinal canal, making the exercise more viable for certain back pain patients. Steps to implementation include research on bench press postural preferences, development of adjustable foot plates, and formal revision to bench press guidelines.

Numerical analysis of the transmission loss of water muffler according to the two-load method

A numerical method for the transmission loss prediction of the water muffler has been provided according to the measuring process of the two-load method. The commonly used acoustic loads can be applied in the proposed method. The accuracy of the proposed method has been proved by comparing the calculated transmission loss with that from the traditional direct predicting method. And then the proposed method is used to discuss effects of test bench on transmission loss measurement. The predicted transmission loss curves are consistent reasonably based on different test models. The location of monitors relative to the muffler inlet and outlet has little influence on the result. But the distance between the two monitors upstream or downstream should be controlled within a certain range based on the concerning frequency band and the main pipe diameter. It is found that modes of the coupled system consisting of the test pipes and the water cause extra peaks on the transmission loss curve. The influence can be reduced by arranging appropriate fixed points. The proposed method can be used to to explain the reasonability and validity of the test bench design.

УСТРОЙСТВО ДЛЯ ИССЛЕДОВАНИЯ ВЛИЯНИЯ МАГНИТНОГО ПОЛЯ НА ХАРАКТЕРИСТИКИ ПАР ТРЕНИЯ «КОЛЕСО - РЕЛЬС»

The paper is dedicated to the circuit diagram substantiation of the specialized roller bench for researches of the magnetic field impact upon wheel adhesion with a rail. On the basis of the analysis of the experimental plants available at present for the study of the contact interaction of wheels with rails it is defined that two-roller benches are the most efficient for the investigation of different outer factors impact upon wheel adhesion with a rail. Taking into account mentioned above there is offered an original design of the two-roller bench equipped with the device for friction area magnetization. Two cylinders with parallel axes are theoretically a friction pair. Taking into account the presence of a non-concurrency arisen at roller manufacturing and mounting a point contact is realized in the bench. A bench formation is carried out according to a modular approach with the installation of rotary magnetic conductors. For the support of the largest magnetization of a friction area in longitudinal and transverse directions and for the decrease of stray flux in the bench there is realized a series connection of roller friction area with the sources of a magnetizing force. For the substantiation of rotary magnetic conductor position choice regarding a friction area of bench rollers there is carried out an analysis of magnetic field distribution in the friction area depending on the location of magnetic conductors. On the basis of the investigation results it is defined that a change of magnetic conductor position changes the orientation of a magnetic field vector, at that a roller friction area is magnetized in transverse and longitudinal directions. 
 In view of this the bench design offered allows investigating the impact of longitudinal and cross magnetic fields upon friction in the contact of a wheel with a rail. Furthermore, it is defined that at small values of an angle between the direction of a magnetic field vector and the plane of a roller friction area a possibility to exclude the effect of roller magnetic additional loading appears.