Installation Height Research Articles

Motion Analysis and Modulation of Steel Particle Swarm in High-Pressure Tank for Particle Impact Drilling

Particle Impact Drilling (PID) is a new technology to effectively improve the rate of penetration (ROP) for oil and gas drilling in hard and strongly abrasive formations. In this paper, numerical simulation method is used to analyze the motion characteristics and the modulation method of particle swarm in high-pressure tank for the particle injection system based on differential pressure ejection in PID. The numerical simulation results show that: when there is no modulation elements, the motion of particle swarm in the high-pressure tank follows an asymmetric funnel flow with pulsating state, which could be divided into vertical flow domain, fast flow domain, slow flow domain and stagnation domain. The unstable dynamic arching effect of the funnel flow, the viscous effect of the liquid bridge force and the collapsing effect of the particle swarm could probably lead to the blockage of the discharge port of the high-pressure tank. When the semiapex angles of the high-pressure tank decreases, the volume flow rate of particles increases and the stagnation domain becomes smaller, but it becomes easier to form arching and blockage. The modelling results indicate that the pulsation of the funnel flow is minimum when the semiapex angle is 45° without the mutilation element, which means the funnel flow of the particle swarm is relatively stable. By introducing a conical modulating element above the discharge port, the unstable funnel flow of the particle swarm could be transformed to an overall uniform flow. The modelling results indicate that the installation height of the modulation element has the greatest influence on the pulsation degree. The optimized parameters for the conical modulation element based on numerical modelling tests are 70° for the vertex angle, 35mm for the length of the flank and 70mm for the installation height.

ЕКСПЕРИМЕНТАЛЬНІ ДОСЛІДЖЕННЯ ПЛУГА З ДИСКОВИМ ПОДРІБНЮВАЧЕМ

Studies were conducted on the operation of a plow with a disk disintegrator in a unit with an MTZ-82 tractor on black soil with a flat relief on soybean stubble with the amount of plant residues from 300 to 400 g/m2. During the research, the following parameters were changed: the disk approach angle, the disk section installation height, and the tractor speed. As a result of the study, it was found that at the speed of a plow with a disk disintegrator from 4 to 5 km/h, the depth of plant residues embedding is maximum and ranges from 15 to 19 cm, while fuel consumption becomes minimal in the range from 18 to 30 kg/ha.

Liquid vibrations in cylindrical tanks with flexible membranes

The objectives of this paper are in studying the liquid vibrations in rigid circular cylindrical shells with internal flexible membranes or covered by membranes. The liquid in the container is supposed to be an ideal and incompressible one, and the fluid motion is irrotational. In above formulated suppositions the velocity potential is introduced; it satisfies the Laplace equation. The boundary value problem is formulated for the velocity potential. To obtain boundary conditions on the liquid free surface, the membrane deflection is considered, and the equality of normal components of liquid and membrane velocities is satisfied. The incompressible and inviscid liquid is supposed to perform irrotational motion in the fluid domain divided into two sub-domains by internal flexible membrane that is installed at the given height. For solutions of the problems both numerical and analytical methods are in use. The analytical solutions of two boundary value problems are obtained for unknown velocity potential and membrane deflection as the Fourier–Bessel series with coefficients depending on unknown frequency. Satisfying boundary conditions, we obtain the system of homogeneous algebraic equations. The condition of a non-trivial solution of this system gives the non-linear equation for evaluating the frequencies. The coupled membrane and liquid vibrations in cylindrical tanks are studied also by FEM and BEM methods. The comparison of results obtained using analytical approach with ones received with boundary and finite element method is provided. The main results are as follows. As follows from numerical simulations, if the membrane is installed inside the cylinder, then the most important parameter affecting the result, is the height of the membrane installation. If the membrane is installed at a considerable distance from the free surface, then the sloshing frequency practically does not change, and more precisely, it slightly increases. The dependencies of frequencies via the filling level are identified. The novelty of proposed approach consists in possibility to study the influence of elastic baffles and roofs in the liquid-filled tanks.

Crosswind influence on heat and mass transfer performance for wet cooling tower equipped with an axial fan

To enhance the thermal performance and relieve the impact of crosswind on the super large-scale natural draft wet cooling towers (SLWCTs), based on our previous research, through the three-dimensional numerical simulation of the SLWCT equipped with an axial fan, the impact of the fan positions on the thermal performance was investigated at various crosswind velocities (1–9 m/s) when the fan power was fixed to 200 kW. It is obtained that the optimized fan diameter and the installation height are 20 m and 18 m. Additionally, the characteristics of the aerodynamic and temperature field inside the tower with different fan positions were discussed based on the above results, subsequently, the change rules of water temperature drop, evaporation loss, and heat transfer coefficient are analyzed. The results manifested that the optimization scheme efficiently relieves the adverse effects of the crosswind, and the air velocity near the fan is significantly increased. By comparison with the case of no fan, the heat transfer coefficient and water temperature drop increase by 4.79% and 0.226 °C, respectively, and the evaporation loss increases by 2.86% at the utmost.

A numerical study of strong-post double-faced W-beam and Thrie-beam guardrails under impacts of vehicles of multiple size classes

Median barrier systems are safety features between opposite travel lanes to redirect or prevent errant vehicles from intruding into oncoming traffic lanes. Different barriers systems have been developed and used for decades. In this study, finite element (FE) modeling and simulations were adopted to study the performance of double-faced W-beam and Thrie-beam guardrails at 29- and 31-inch installation heights. The in-service guardrail performance was evaluated under impacts of multiple sized vehicles at Test Level 4 and Test Level 5 conditions specified in Manual for Assessing Safety Hardware (MASH). The effectiveness of the guardrails was assessed using guardrail dynamic deflections, vehicle responses, and vehicle redirection characteristics. The MASH exit box criterion, MASH evaluation criterion F (roll and pitch angle limit), and MASH evaluation criterion N (vehicle trajectory) were adopted in the evaluations. Additionally, occupant safety and injury risk were determined using occupant impact velocities (OIVs), occupant ridedown accelerations (ORAs), and acceleration severity indices (ASIs). The crash simulation results showed that both W-beam and Thrie-beam guardrails could retain all test vehicles and prevent them from getting into oncoming travel lanes. All the guardrails were considered generally effective in terms of occupant risk factors and vehicle impact responses. It was also observed that in certain cases, the installation height and the type of guardrail blockout could affect the impact severity for small-sized vehicles.

Design of pulse cleaning device for single-filter cartridge dust collector by multi-factor orthogonal method based numerical simulation

To solve the problem of difficulty in dust removal from single-filter cartridge dust collector equipment in confined space, an orthogonal experimental design and numerical simulation methods were adopted to optimize the ash-cleaning device. The study found that the diameter of the cone base has a greater impact on the pulse cleaning performance of the dust collector than the angle of the cone, and the installation height L has the least impact. When the optimal parameters θ = 55°, D = 80 mm, L = 0 mm, compared with the traditional dust collector, the average dust concentration at the outlet of the equipment is reduced by 11.5%, the number of cleanings is reduced by 37.5%, and the pressure at the lower part of the filter cartridge is reduced. 34.7%, the upper part increased by about 53.9%. The problem of uneven cleaning of filter cartridges in confined spaces is solved, and equipment performance is improved.

CFD simulation of HC-290 leakage from a split type room air conditioner

HC-290 is one of the alternatives to HCFC22 in room air-conditioners. With the phase-down schedules in Kigali Amendment, it is imperative to use HC-290. However, there are concerns about its flammability in the event of a leak from the AC indoor unit (IDU). IEC 60335-2-40 has been revised to extend the capacity ranges for A2L refrigerants and is being further revised with a focus on A2 and A3 refrigerants. In real-life situations, furniture and occupants are present inside the room and these may positively or negatively influence the dispersion of any leaked HC-290. CFD simulation of dispersion of leaked HC-290 has been carried out for a variety of scenarios. The variables include leakage rates, IDU installation heights, IDU blower ON or OFF and types of furniture. Furniture, in general, appears to promote mixing, thereby reducing HC-290 stratification. The maximum concentration occurs on the side where the leak is directed by the momentum of the jet from IDU. There is no significant effect on the concentration distribution by the type and size of furniture with legs, although solid furniture has some marginal effect due to reduction of room free volume. The average concentration of HC-290 in the room is slightly more when the solid furniture like cupboards are placed some distance away from the IDU. The highest concentration at 30 cm above floor level, is 44% of LFL when the blower is ON, while it is 62% when the blower is OFF.

A morphology-based evaluation on block-scale solar potential for residential area in central China

Block-scale application of photovoltaic technology in city is becoming a viable solution for renewable energy utilization. Rapid urbanization process has made urban buildings have huge development potential for solar energy in China, especially in residential areas that occupy large parts of the city. However, the residential blocks in China show differences in the morphological layout and parameters, which means they have diverse potential for solar energy development. This paper studies the effect of quantified morphological parameters on solar potential for residential blocks in Wuhan, China. The distribution characteristics of solar potential in different block environments are discussed. Various strategies are evaluated in terms of the installation position and height of PV modules. The results showed that floor area ratio, building density, average building height and building interval have significant impact on solar potential for residential block, and their correlation can reach 75%, 71%, 78% and 72% respectively. The average PV installation ratio of roof, south facade and west facade can reach 96%, 32% and 39% respectively. The results of this paper not only provide a reference to the block-scale application of PV technology in urban environment, but also stimulate the implementation of photovoltaic policies on various residential blocks in China.

Effects of granulator structure and cooperating mode with slag tube on the centrifugal granulation characteristics of molten slag

Molten slag flows to the edge of the rotating cup and is rapidly broken into droplets under the centrifugal force provided by the high-speed rotating cup. The diameter of the droplets is closely related to subsequent waste heat recovery and resource utilization. To clarify the law of centrifugal granulation of molten slag, the effects of the structure parameters of the rotating cup, the way the slag tube and the rotating cup are matched, and the eccentricity on characteristics of molten slag are investigated in the paper. In the present work, an unsteady, three dimensional, and two-phase model is established to analyze the influence of the above factors on the particle size distribution, average particle size, and maximum and minimum particle size of the granulated slags. As a result, in the range of 0–45°, the increase of the inclination of the inner wall surface of the rotating cup can strengthen the granulation effect. To ensure the granulation effect, the ratio of the diameter of the slag tube to the rotating cup should not exceed 0.44, and the installation height of the slag tube should be as close as possible to the granulator. Moreover, to make the particle size uniform after granulation, the slag eccentricity is kept within 5%. Finally, the dimensionless correlation of the diameter of droplets was obtained to guide industrial practice to control the particle size of the granulated slag particles in the paper.

Wind-Induced Vibration Control of High-Rise Structures Using Compound Damping Cables

Based on the vibration reduction mechanism of compound damping cables, this study focuses on the wind-induced vibration control of high-rise structures with additional mass at the top. The differential equation of motion of the system under the action of the composite damping cable is established, and the analytical solution of the additional damping ratio of the structure is deduced, which is verified by model tests. The vibration response of the structure under the action of simple harmonic vortex excitation and randomly fluctuating wind loads is studied, and the effect of different viscous coefficients of the dampers in the composite damping cable and different installation heights of the damping cable on the vibration control is analyzed. The results show that a small vortex excitation force will cause large vibrations of low-dampened towering structures, and the structure will undergo buffeting under the action of wind load pulse force. The damping cable can greatly reduce the amplitude of structural vibration. The root means square of structural vibration displacement varies with damping. The viscosity coefficient of the device and the installation height of the main cable of the damping cable are greatly reduced.

The Influence of Antenna Height on the Measurement of Collective Variables Using an Ultra-Wide Band Based Local Positioning System in Team Sports.

Ultra-wide band (UWB) based local positioning systems (LPS) are based on devices and a portable antenna set. The optimal installation height of the antennae is crucial to ensure data accuracy. Collective variables are metrics that consider at least two pairs of coordinates, which may lead to lower precision than an individual one. Therefore, the aim of this study was to compare the influence of antenna height with collective metrics using a UWB (i.e., IMU; WIMU PRO™, RealTrack Systems, Almeria, Spain) based LPS. Data acquisition was carried out in a basketball court measuring 28 × 15 m. Five devices were used; one of which was carried by a healthy and well-trained athlete (age: 38 years, mass: 76.34 kg, height 1.70 m), while each of the remaining four was positioned on a tripod in one of the four corners of the court. Four kinds of variables were extracted: (1) static distances, (2) dynamic distances, (3) static areas and (4) dynamic areas in all antenna installation modes of 0.15, 1.30 and 2.00 m. The results showed that the antenna of 1.30 m provided better accuracy for all measures (% difference range from −0.94 to 1.17%) followed by the antenna of 2.00 m (% difference range from −2.50 to 2.15%), with the antenna of 0.15 m providing the worst accuracy level (% difference range from −1.05 to 3.28%). Overall, the measurements of distance metrics showed greater accuracy than area metrics (distance % difference range from −0.85 to 2.81% and area % difference range from −2.50 to 3.28). In conclusion, the height of the antennae in basketball courts should be similar to the height at which the devices are attached to a player’s upper back. However, as the precision is sensitive to the magnitude of the measure, further studies should assess the effects of the relative height of antennae in team sports with greater playing spaces.

Agrophotovoltaic Designs : Irradiation Analysis on and under PV Modules

To secure agricultural benefits and PV power generation from an agrophotovoltaic system, it is vital that the PV modules and the crop are both irradiated by light. The configuration and design of PV modules have a practical effect on the irradiation uniformity in an agrophotovoltaic system. Irradiation non-uniformity can cause crop growth delays and quality deterioration during different cultivation periods. This paper proposes the design considerations and parameters of an agrophotovoltaic system to optimize crop yield and power energy production. The design parameters are the PV module installation height, ground coverage ratio, tilt angle, azimuth angle, and PV module installation type. The PV module installation type is classified into dual-axis tracking, single-axis tracking, south fixed, and horizontal fixed. We configured a 3D modeling simulation platform to visualize and analyze irradiation under the PV module. Finally, we suggest three evaluation parameters: The overall mean under PV modules, the overall standard irradiation deviation under PV modules, and the transposition factor of the agrophotovoltaic designs.

A METHOD TO PREDICT FOULING ON MULTI-STOREY BUILDING MOUNTED SOLAR PHOTOVOLTAIC PANELS: A COMPUTATIONAL FLUID DYNAMICS APPROACH

The influence of installation and environmental parameters on dust particle deposition behavior on solar photovoltaic collectors were investigated using Computational Fluid Dynamics (CFD) simulation. Parameters including tilt, height of installation, dust particle size and wind speed were investigated. Modeling of wind flow on the building and the photovoltaic array was achieved using the Shear Stress Transport k-ω turbulence model. The discrete phase model was adopted for dust motion prediction and a model was developed to assess the impact of dust accumulation on the performance of the photovoltaic array. The study revealed that rooftop installations have less dust deposition unlike the ground-mounted installations. The wind flow characteristics on rooftop installations are greatly affected by the building while on ground mounted installations wind flow is only influenced by the tilt of the solar photovoltaic collector. Different tilt angles, wind speeds and particle sizes had different deposition characteristics. The lower impact velocities experienced on ground mounted Photovoltaic (PV) arrays resulted in more deposition for smaller sized (10µm) dust particles compared to the larger sized (50µm and 150µm) particles. On rooftop installations, dust particle size of 150µm had the most deposition at a velocity of 5m/s and hence it resulted in a 22.61% reduction in solar photovoltaic efficiency while the least reduction in efficiency of 1.32% was recorded at 15m/s and 10µm size dust particles. The tilt angles of 0o and 22.5o had large sized turbulent eddies compared to the tilt of 45o. The study revealed that ground mounted photovoltaic arrays had more dust deposition compared to rooftop mounted photovoltaics.

Traffic Flow Statistics Method and Practice Based on Roadside Video with YOLO_V3

Temporary traffic flow observation plays a pivotal role in transportation planning, consultation, and decision-making, and it supplements fixed long-term traffic observation data. Although substantial automated technology has been used for traffic observation, such technology is limited by the temporariness and uncertainty of observation points; moreover, these methods are difficult to use in temporary observations. In this study, the YOLO_V3 algorithm, which is based on deep learning, is used for vehicle detection based on roadside videos of temporary observations. Moreover, a secondary detection framework based on vehicle detection and traffic counting regions is proposed. Then, a traffic counting pattern with Kalman filter, Hungarian allocation, and perspective projection transformation is established. In addition, by collecting multiple sets of actual video data, the effectiveness of the method under different conditions is analyzed in terms of three indicators: camera intersection angle with the road, erection height, and road traffic density. Results show that at a camera height of 3 m and a roadside angle of 30°, the accuracy is approximately 95%. However, traffic flow accuracy drops to approximately 90% when vehicles are blocked by large buses and trucks during detection. In this study, the algorithm is tested for execution efficiency using 1080p video streams on a Windows 10 x 64 operating system, a 2080Ti graphics card, a 64 GB RAM, and an i7-7820X CPU. Results show that camera installation angle and height have no considerable effect on operation efficiency. Under low-density traffic, the frames per second (FPS) value is approximately 44; under high-density traffic, the FPS value drops to approximately 33, indicating that the method still has high execution efficiency and can be used for real-time video traffic counting.

Optimization of a motorcyclist protection system made of recycled rubber – impact simulation and test uncertainties

This paper describes the design and optimization of a safety barrier to protect motorcyclists in case of an accident, using, as a basis, rubber from used tires. The proposed motorcycle protection system (MPS) attempts increase motorcyclist protection in roads. But, at the same time, it offers a new alternative for the reuse of rubber from used tires, thus contributing to solving the environmental problem created by this type of waste. A first pre-design was proposed and tested according to UNE-135900 standard to evaluate the protection level against motorcyclist impact. Then, a finite element model of the new MPS and the dummy was used to reproduce the experimental impact tests. The model was validated and adjusted using data from material characterization tests and from a full-scale crash test carried out on a first prototype. The main design parameters influencing the deformation shape and the effort peaks obtained during impact were analyzed. Several modifications over the original barrier were made in order to meet the requirements of the standard. The new design of the barrier was tested, showing a lower severity than the initial prototype. In view of the results, the use of rubber appears to be technically feasible for the manufacture of these motorcyclist protection systems. However, some discordances were found between the injuries measured in the tests and the expected results obtained by simulation. High sensitivities to small variations in installation height and/or slight movements of the dummy’s head during the launch phase are pointed out as possible causes.

Energy simulation of p-PERC bifacial modules based on different installation environment

The bifacial-cell module can significantly increase the power output due to the back power generation gain, and is becoming research hot. In this paper energy simulation analysis is based on three types of systems in different regions, and the installation tilt, ground albedo and height above ground are compared respectively. The irradiation is dominating to produced energy. The modules located in Yinchuan under the situation of albedo 0.2, tilt 15° could generate 85.2 MWh/year, which is 6.1 MWh/year higher than the modules located in Beijing under the situation of albedo 0.8, tilt 30°. The modules generate more power under the situation that the installation tilt is close to latitude, the optimal tilt of Beijing, Yinchuan and Guangzhou is 30°, 30-35° and 15°. The higher the albedo of the ground, the greater the impact of tilt changes on produced energy. Meanwhile, the increasing height above ground promotes to the higher energy. And the produced energy is more sensitive to the variable value of ground albedo compared with height.

Application of coupled multi-body dynamics—discrete element method for optimization of particle damper for cable vibration attenuation

With the application of the particle damping technology to cable vibration attenuation, the rootless cable damper overcomes the limit in installation height of existing dampers. Damping is achieved through energy dissipation by collisions and friction. In this paper, a coupled multi-body dynamics—discrete element method is proposed to simulate the damping of the damper—cable system under a harmonic excitation. The analyses are done by combining the discrete element method in EDEM and multi-body dynamics in ADAMS. The simulation results demonstrate the damping efficiency of rootless particle damper under different excitations and reveal the influence of the design parameters on its performance, including the filling ratio, particle size, coefficient of restitution, and coefficient of friction.

Modeling the dispensing process for chopped stalk fodder

Optimization of the parameters of mechanized processes of dosed delivery of crushed stalk fodder is given, which required the development of programs for modeling these technological processes with a quantitative assessment of the functional indicator of the quality of their implementation. This made it possible to substantiate the solutions of technological processes that ensure their implementation within the specified requirements. The use of a KTU-10A fodder dispenser and a stalk fodder dispenser for dispensing stalk fodder in production lines allows reducing the unevenness of the dispensed fodder flow by 3.6 times compared to using the KTU-10A fodder dispenser. It is advisable to accept the following kinematic parameters of the working bodies of the batcher: rotation frequency of the conveyor drive drum n = 120 min-1; the circumferential speed of movement of the ends of the fingers of the scraping drum is 1.8 m/s with a drum diameter D = 0.68 m; the maximum installation height of the stripping drum above the conveyor belt h = 0.3 m; conveyor belt width b = 0.6 m; power for the batcher drive is 1.5 kW, which ensures uneven delivery of ±5%. The dispenser provides a stable dosing of roughage (with a minimum mass flow rate of 0.2 kg/animal) in accordance with zootechnical requirements.

Improving Energy Efficiency of Irrigation Wells by Using an IoT-Based Platform

The irrigation sector has undergone a remarkable transformation in recent decades due to the application of pressurized water distribution technologies, improving the management of limited water resources. As a result of this transformation, irrigation has become, together with agricultural machinery, the primary consumer of energy within the agri-food sector. Furthermore, the energy cost of operating pumping equipment during a farming season represents 30–40% of the crop’s total cost. For this reason, one of the most interesting challenges in this scope is that of improving energy efficiency and reducing economic costs so that productive work become more and more competitive. Energy audit makes possible to determine the efficiency of installations, and enables to determine energy saving protocols (requirements), for this reason the aim of this article is to carry out these by using IoT-based systems. The proposed system improves decision-making on agricultural pumping management by classifying wells’ efficiency and integrating the data sets that determine their efficiency into a single information model. The system monitors energy efficiency according to different parameters such as: infrastructure, energy consumption, electric rates, manometric height or type of installation, making it possible to enhance each pumping operation’s decisions. This solution has been deployed in an irrigation community in southeast Spain whose results have warned about the lack of efficiency in two of its wells: in one of them it is proposed that they be replaced, due to the high cost of pumping water, and in the other, hydraulic mechanisms are implemented to improve the water-energy binomial.

Reservoir bank slope stability prediction model based on BP neural network

Safety monitoring and stability analysis of high slopes are essential for construction of concrete dam in precipitous gorges or mountainous areas. The estimate of slope stability is a difficult engineering shortcoming with a number of variables. Thereafter, a hybrid model of Support Vector Regression (SVR) and Teaching–learning-based optimization technique (TLBO) is proposed to develop the predicting function. TLBO was used in obtaining the best SRV factors to improve the prediction accuracy. Few essential factors, such as the installation height of instruments, classification of rock masses, modulus of elasticity, the complete measuring time cycle, the excavation height of slope, the start measuring time, and the actual excavation height after measurement are considered as the input parameter, but the slope displacement is regarded as output. The outcomes showed SRV-TLBO a reliable hybrid accurate prediction of slope stability, then it was effectively used to the left abutment slope of Jinping I hydropower station located in Yalongjiang concrete dam reservoir as a novel method for this purpose.