Low Rpm Research Articles

Permanent magnet DC motor control by using arduino and motor drive module BTS7960

This study proposes a control system for permanent magnet DC (PMDC) motor. PMDC drive control system has two critical parameters: control and monitoring. Control system includes rotation speed control and direction of rotation of motor using motor drive module BTS7960. The PWM signal has a fixed frequency of waves with varying duty cycles (between 0% and 100%), so the motor rotation can be regulated gradually using a potentiometer already programmed on the Arduino Uno board. The motor rotation direction setting uses the H-bridge circuit method using a 3-way switch to set the direction of forward-reverse rotation of the motor. The monitoring system includes measurements of rotational speed, current, and voltage. Motor rotation speed can be adjusted from the armature voltage settings through the duty cycle PWM setting so that the motor speed can be increased or decreased by the desired duty cycle. From the unload PMDC motor test results it has also been shown that the torque of the motor is relatively constant when there is a change in speed from low rpm to high rpm or vice versa.

Numerical aeroacoustic analysis of propeller designs

ABSTRACTAs propeller-driven aircraft are the best choice for short/middle-haul flights but their acoustic emissions may require improvements to comply with future noise certification standards, this work aims to numerically evaluate the acoustics of different modern propeller designs. Overall sound pressure level and noise spectra of various blade geometries and hub configurations are compared on a surface representing the exterior fuselage of a typical large turboprop aircraft. Interior cabin noise is also evaluated using the transfer function of a Fokker 50 aircraft. A blade design operating at lower RPM and with the span-wise loading moved inboard is shown to be significantly quieter without severe performance penalties. The employed Computational Fluid Dynamics (CFD) method is able to reproduce the tonal content of all blades and its dependence on hub and blade design features.

Design of Vibrate Generator

Vibrate generator is an electric generator, which generate electric by a magnet vibration. This research inspired by the discovery of windbelt by Humdinger. The purpose of this research is to prove electric generator with magnetic vibration, to design low rpm vibrate generator. Electric generator in this vibration is simple, expected to be made society with local material. With an energy source from a ditch drainage or wind, this generator are supposed to generate electricity for one house. Major component generators are bar magnets, springs, wire coils, diode, capasitor and wood board. The principle of generator unit is a magnet attached to the spring and the end of the spring attached to the wooden board. If the spring is vibrated, magnetic vibrations produce a magnetic flux change that penetrates the wire coil who attach beside a magnet. A wire coil penetrated flux magnetic which change with time to produce electro motive force. Every unit generator produce AC and changed to DC by Diode Bridge. The experiment results were one unit cell generator produce 2.2 volt peak to peak, 21.47 Hz, and product duration 0.5second. The design of a low rpm vibrator generator is built from a vibration generator unit arranged and connected in parallel. Each unit vibration generator is vibrated sequentially, in order for a continuous power generation.

АВТОМАТИЗИРОВАННАЯ СИСТЕМА УПРАВЛЕНИЯ РАБОТОЙ БЕНЗИНОВОГО ВПРЫСКОВОГО ДВИГАТЕЛЯ В РЕЖИМЕ ХОЛОСТОГО ХОДА

The purpose of research is improving the petrol fuel injected (injector) motor vehicles in mode independent of idling by the fuel-air mixture composition control adjustment by an automated control system that provides reconfiguration (reprogramming) of standard motor controller for the air / fuel mixture corresponding to the specified high-speed idling. The article is devoted to solving problems related to the operation of the engine with injected fuel at low rpm model of independent mode is idle (at stops and Parking of motor vehicles with the engine running) that is due to poor mixture formation is characterized by impaired flow of operating the process of the cylinders. Developed a new way of working gasoline engine with fuel mode injection independent of idling and automated system for its implementation, allowing the air / fuel mixture adjusting through the regular reprogramming the engine control module on the air-fuel mixture corresponding to the specified high-speed idling. The advantage of this system is the compactness, wide availability of components and the ability to quickly connect to the circuit established to the engine controller. Studies show that the use of the automated system control the operation of a fuel injected engine in a mode independent of idling allows to reduce the minimum stable engine speed is up to 300-600 min-1, the operational fuel consumption by 15-20%, the content of harmful substances in exhaust gases by 30-60% compared to engine operation in normal configuration

Morphological Analysis of Foamed HDPE/LLDPE Blends by X-ray Micro-Tomography: Effect of Blending, Mixing Intensity and Foaming Temperature

Non-invasive x-ray micro-computed tomography was employed for thorough quantitative and qualitative analysis of the cellular structure of foams made of linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and their blends. Special emphasis was given to the differences between the results of 3D and 2D analyses, to evaluate the possible errors while studying the morphology using conventional 2D techniques (e.g. SEM). Blends with the weight compositions of 90%LLDPE/10%HDPE and 75%LLDPE/25%HDPE were produced at different rotor speeds of 10, 60 and 120 rpm and batch foaming was examined over a wide range of temperature. The void fraction values from 2D and 3D analysis were found to agree well with those obtained with the Archimedes method. Results showed more uniform cell size distribution for blends mixed at the lower spectrum of screw rotational speed. Among the blends with higher void fraction values and relatively uniform cellular structure, higher average cell size (3–30%) and cell population density (1.25–2.5 times) were noticed in 3D analysis compared with 2D data. The micro-CT images at different cross sections revealed anisotropic cell growth and more elongated cells along the thickness of the specimen. It was also observed that, with increase in foaming temperature, cell shrink prevailed over cell coalescence in the samples with lower viscosity (prepared at low rpm of 10), while for those with higher viscosity (prepared at an rpm of 60) cell coalescence was more dominant.

Gears Steer New Engine Designs

This article reviews the development of geared turbofan (GTF) engines. GTF engines have a hub-mounted epicyclic gearbox that drives the front-mounted fan at lower rotational speeds than the engine turbine section that powers the fan. The turbine driving the fan is most efficient at high-rotational speeds. The fan operates most efficiently and creates less noise at lower rpm. The operating gear reduction ratio also permits increasing the engine’s bypass ratio with larger fans. Gear trains are one of the oldest known machines, and none is more closely identified by the general public with the profession of mechanical engineering. Pratt & Whitney is in production of their first generation of GTF engines in the 18,000–30,000 lbt range, which power twin engine single-aisle, narrow body 70–200 passenger aircraft. The GTF combines existing jet engine technology with the well-established mechanical engineering technology of gears.

Design and Performance Test of Axial Halbach Brushless DC Motor with Power Density 1.5 Kw/Kg

Progress of technology on electric vehicle component sector is one reason the emergence of electric vehicles at the moment. Starting from battery which has a great current density up to the automatic control systems on electric vehicles. But there are still some shortcomings of this electric vehicle components, one of which is the low value of power density of existing electric motor in the market today. On vehicles such as electric cars when Race Car Contest, energy saving problems about power density of the driving motor is very vital. This is because the total weight of the vehicle has a huge influence on the vehicle efficiency is against it. The issue is one of the reasons of the research task. In this final task is done making the design, simulation, and architecture of the Axial Halbach Brushless DC Motor. Use of system configuration on the halbach magnet to avoid the use of iron as a material cantilever rotor. By changing the material of the cantilever rotor with lighter materials such as aluminum or even carbon fibre, the value of power density electric motors can be increased. Then using the litz wire on coil stator to reduce loss-power loss due to the barriers on the coil. Coreless stator on the system and to avoid the phenomenon of cogging at the time due to low rpm style attraction magnet with iron in the core material. While the creation process begins by determining the specifications of the Axial Halbach Brushless DC motors. Then go into the design phase of the mechanical and electrical design. Who then conducted simulations to help determine other parameters such as air gap, slot turn, and magnetic orientation. The process of making a component of stator and rotor after the simulation is completed. After all the components of the rotor and stator on assembly, mounting the hall sensor is carried out to the right to position obtained by reading the signals. After the motor can spin with good motor performance, testing can be done. This final task generates Axial Halbach Brushless DC Motor with construction of one rotor and a stator. Axial DC Brushless Halbach Motor consists of 10 pole halbach magnet system permanent and 30 slot on the stator. On the performance test of Axial Halbach Brushless DCMotor it obtained efficiency of 92.72%, power output of 807.34 Watts, torque of 2.24 Nm, moment rpm 3451. As well as the power density of 0.588 kW/kg at 50% throttle openings

Preparation and Characterization of Al6061 with Micro Silica MMC

In this investigation, the influence of micro silica (SiO2) particles dispersion in AA6061 matrix material prepared through stir casting route for different weight percentage of reinforcement. The fabricated composite have been examined under optical microscope for dispersion of reinforcement particles. Microstructure of the composites revealed that the reinforcement particles are uniformly distributed in stir casted composite with low rpm of stirrer. It was observed that the micro hardness increased with increased silica content in Al metal matrix composite. It is also observed that with increasing micro silica particles reinforcement in Al matrix forming Mesoporous structure.

Study of the Optimization of the SCR Catalyst Position in by Exhaust System of using Mixer

Background/Objectives: This research analyzes the influence of Urea SCR System's mixer and optimization of the Catalyst's position through post technologies in order to satisfy the Euro 6 regulations. Methods/Statistical Analysis: The simplified modeling was facilitated to interpret the current exhaust system. Considering the latter as the background, ANSYS was used for the Analysis. As for the method of Analysis, 5 flux variables were considered from exhaust flux of 1,000rpm~3,000 rpm in increments of 500 rpm. Findings: When the flux passes through the mixer, the speed dispersion increased and as the rpm increased, the results showed that 1,000 rpm compared to 3,000 rpm, the back pressure elevated over 500 Pa. By assessing the degree of uniformity, the uniformity expanded faster at high rpm and in low rpm, the flux itself is low so the uniformity gradually increased as it reached the latter part. Overall efficiency of over 95% was achieved at approximately 15~20 cm and in the points after that, the degree of uniformity gradually decreased in the graph. Therefore, it was determined that optimal position for the SCR catalyst should be 20~50 cm from the posterior of the mixer. Application/Improvements: This research was analyzed of the distribution uniformity effect in the exhaust system, the analysis result could be optimized of catalyst-position and improved uniformity index.

Estudio del proceso de combustión en un motor de alto swirl empleando mecánica de fluidos computacional

The numerical simulation of spark ignition engines has uncertainties that compromise the reliability of the results due to the interrelationship between chemical dynamics and flow kinematics within the combustion chamber. This work evaluated the effect of using different reaction mechanisms applied to a G-equation combustion model and its interaction with the velocity field inside the combustion chamber of a CFR engine, which has special technical characteristics (high swirl and low rpm) that allowed the study of this phenomenon. The research was carried out numerically by computational fluid dynamics (CFD) techniques: using a G-equation combustion model (with and without reaction kinetics) and a RANS -k−ϵ- RNG turbulence model. The numerical simulation was compared and validated against reported experimental pressure indicator diagram. The influence of reaction mechanisms and swirl in the development of the flame front and associated variables within the combustion chamber was studied. Finally slight discrepancies were found between reaction mechanisms used in this study that could be important in simulations of spark ignited engines that are different from the one studied. It was noted that an increase in the intensity swirl yields a flame development deviation from the theoretical models. The current codes and simulation techniques require tuning of various parameters, and thus, the validation against experimental data is needed before drawing conclusions from the numerical cases.

Development and friction estimation of the Half-Toroidal Continuously Variable Transmission: A wind generator application

This paper presents the modeling and the computer simulation of a continuously variable transmission (CVT), applicable to a (2kWatt power) wind turbine, as well as the evaluation of the suggested mechanism. Transmission in conventional wind turbines offers a constant ratio, as a result the rotational speed of the generator's shaft varies depending on the wind speed, so the generator usually operates at lower rpm than registered, leading to low power output. In contrast, wind turbines equipped with a CVT system offer a wider range of the power generator's shaft speed.The proposed mechanism is expected to provide a constant output shaft speed for any wind speed, maximizing the power produced. Furthermore, it is expected that the system will be able to collect more energy than conventional wind turbines and wind turbines equipped with CVT do, starting from a lower wind speed. This paper describes the operating principle of the proposed mechanism, followed by the mechanical designs of the individual components. Dynamical and Frictional Analysis of the proposed mechanism and its components are presented. The modeling of the CVT was performed using CATIA, and simulation carried out using the MSC Adams 2013 student edition.

Void Closure in a Large Cross Section Bars Hot Rolled from a Low Alloy Steel Ingot Casting

The void closure phenomenon of a large size rolled bar made from an as-cast low alloy steel ingot of grade AISI 4130 has been examined. The study involved FEM based simulation of hot rolling of a four metric ton ingot casting to a final product of 320 mm round corner square cross section with a reduction ratio of 4.3. The rolling process was varied at two process conditions. The process variables considered included initial cooling time of the ingot from soaking pit before rolling, rpm, reduction and pass schedule. The defects in the product at the two rolling conditions were experimentally evaluated using ultrasonic technique during hot rolling and compared with void fraction in the simulation. Higher initial time of cooling of the ingot before hot rolling, lower rpm, higher reduction and lesser number of tilts gave products with least core defect which justified simulation results. The study brought out at every stage the load and torque distribution, effective strain, stress triaxiality factor, void volume fraction and void healing hydrostatic integration parameter in the model which had enabled void closure.

Vibration control by propeller design

Propeller research has generally been focussed on improving the open water efficiency, and by considering the various energy losses associated with the marine screw propeller, it can be seen that for a design brief with given main engine power and RPM input, plus a thrust requirement defined by the specified ship speed, the most fruitful area for improvement in efficiency by propeller design is a reduction in energy losses. The simple way to increase the efficiency is reduction of blade area, increasing load near the tip and adopting a larger diameter with low RPM. However, vibration and noise will be the first issues when a designer tries to increase the efficiency of the propeller by these ways. This paper will present a simple prediction method of pressure fluctuations induced by thickness, propeller loading and unsteady cavitation taking not only propeller dimensions but also stern shape into account at the beginning of the propeller design.

Algorithm of actions to identify and reduce risks in the production of milk and plant products

Foods with a new generation of functional and improved consumer properties, corresponds to the modern concepts of nutrition science and consumer needs. functional food production is a major global trend in food science and the subject of innovation. One of the important trends is the use of plant complexes and plant food systems. Using the plant complexes (PC) and plant food systems (PFS) provides a number of benefits: improved consumer properties of the product, do not need to change the process, it is possible to control directional rheological properties and consistency of the finished products, reduced the number of risk points in the production cycle. This paper describes the development of an algorithm of action to identify and mitigate risks in the production of milk and plant products. Also conducted a risk analysis, identified and assessed the risks in the process of production, installed capacity of available resources to reduce the level of risk. Established and submitted to the critical control points in production processes, as well as the critical limits for each critical control points, and the procedure for corrective action in case of violations of the past. During the study, measured changes in the quantitative and qualitative composition of microflora of semi-finished and Quantity of Mesophilic Aerobic and Facultative Anaerobic Microorganisms (QMAFAnM). To determine QMAFAnM samples were taken: 1 – cheesecakes (control), 2 – cheesecakes with RPS. Microbiological studies analyzed frozen-conjugated semi-finished products was determined within 90 days. It is clear from the data that the cottage cheese with semi-finished products have a lower RPM 11.7%. Analyzing the data, it is possible to conclude that the physico-chemical, organoleptic and microbiological indicators of products was developed to set standards on cheese semi-finished products. multilevel structure that characterizes the quality indicators has been developed and is presented on the basis of the survey. The developed algorithm for monitoring critical control points on the complex and the individual indicators will improve the quality and safety evaluations of new food products.

시험과 전산해석을 이용한 고고도용 프로펠러 성능 분석

Wind tunnel experiment and computational analysis have been carried out to evaluate the performance of propeller for scale electric-powered HALE UAV, named EAV-2H+. Performance curves are measured for three propellers and their adequacy for EAV-2H+ installation is examined through consideration of operating conditions. Decline in performance coefficients is observed in low rpm region. Also, the effect of transition tape on propeller performance is measured and analyzed. The computational performance analyses are carried out by using commercial CFD program. The thrust and power coefficient from computations show good agreement with experimental results. Performance coefficients are compared and the influence of measurement device which contributes to discrepancy of the results is examined. Transition SST model is confirmed to yield the tendency of performance decline in low rpm range, similar to experimental observation. The decrease in aerodynamic performance of blade element due to low Reynolds number is identified to cause the decline in propeller performance. Analyses for high altitude conditions confirms degradation in propeller performance.

Feasibility of Pump Speed Modulation for Restoring Vascular Pulsatility with Rotary Blood Pumps.

Continuous flow (CF) left ventricular assist devices (LVAD) diminish vascular pressure pulsatility, which may be associated with clinically reported adverse events including gastrointestinal bleeding, aortic valve insufficiency, and hemorrhagic stroke. Three candidate CF LVAD pump speed modulation algorithms designed to augment aortic pulsatility were evaluated in mock flow loop and ischemic heart failure (IHF) bovine models by quantifying hemodynamic performance as a function of mean pump speed, modulation amplitude, and timing. Asynchronous and synchronous copulsation (high revolutions per minute [RPM] during systole, low RPM during diastole) and counterpulsation (low RPM during systole, high RPM during diastole) algorithms were tested for defined modulation amplitudes (±300, ±500, ±800, and ±1,100 RPM) and frequencies (18.75, 37.5, and 60 cycles/minute) at low (2,900 RPM) and high (3,200 RPM) mean LVAD speeds. In the mock flow loop model, asynchronous, synchronous copulsation, and synchronous counterpulsation algorithms each increased pulse pressure (ΔP = 931%, 210%, and 98% and reduced left ventricular external work (LVEW = 20%, 22%, 16%). Similar improvements in vascular pulsatility (1,142%) and LVEW (40%) were observed in the IHF bovine model. Asynchronous modulation produces the largest vascular pulsatility with the advantage of not requiring sensor(s) for timing pump speed modulation, facilitating potential clinical implementation.

1000cc급 가솔린 엔진의 내구성능 개발

In this paper, durability test of 1000cc level gasoline engine has been carried out. Durability test set total 300 hours and WOT condition. Engine torque, power, fuel consumption, blow-by gas flow rate, and oil pressure are measured to analyse performance variation by time. As a result, engine performance of high rpm range gradually reduced by time but for relatively low rpm range shows stable performance. Blow-by gas flow rate shows 0.4% of averaged induction air flow rate, which is excellent rate for 1000cc level gasoline engine. Engine torque and fuel consumption data show the break-in upto 100 hours and aging trend after that. After 300 hours, engine is disassembled and each part is checked for the damage or crack.

CHARACTERIZATION OF PERODUA MYVI K3-VE I4 ENGINE PERFORMANCE USING EXHAUST GAS RECIRCULATION (EGR)

Internal combustion engines are the main power source for automobile vehicles. As current emission regulations becomes more stringent, more fuel efficient and less polluting engines are becoming the focus of car manufacturers. This paper presents the study of improving the performance of K3-VE I4 internal combustion engine that is used in the Perodua Myvi for the Perodua Eco-Challenge 2013. The strategy was to use an EGR system to reduce Brake Specific Fuel Consumption (BSFC) while maintaining or increasing the engine power. The effects of different location of EGR on the engine performance were tested on a chassis dynamometer. The sensitivity of the engine performance and gas emission were studied since EGR implementation plays a major role in influencing NOx emission. The performance parameter such as engine power and BSFC were then analysed. The result shows that a significant increase of power can be achieved and a reduction of around 56% was obtained on the BSFC. While the best NOx reduction was around 93%. These improvements are obtained at low RPM that corresponds to Perodua Eco-Challenge’s objective.

The Study of Ducted Propeller in Propulsion Performance of a Malaysia Fishing Boat

Through the installation of ducted propeller,fishing vessels are able to operate with more towing power and will be more economic in terms of fuel usage. The application of the shroud or ring to the propeller made the propeller more practical for tugs, pushboat, supply ship and trawler. The study of this paper is focused on the propulsive performance by ducted propeller when operating at tow speed and low rpm. From the research on the ducted propeller, the design characteristics such as length-diameter ratio and thickness-length ratio are determine from the chart provided by previous researcher. The design selection of nozzle is done with the use of CFD program, Javafoil to analyze the flows of the profile and it’s characteristic. Model tests were conducted by using a 26m fishing boat model with and without nozzle.It is foundthat by using ducted propeller to a fishing vessel, thrust can be increase up to 23%.

Improving Energy Efficiency in New Trawlers Fishing Gear in Mediterranean Sea

The objective of this work is to show the benefits of a new eco-systemic fishing gear installed in three bottom trawlers after one year using it. The study has been based on fuel consumption reduction for the three vessels and the catch in two of them. The new system minimizes the impact of the fishing gear on the seabed, with a reduction on the tow resistance. This generates significant fuel savings that improves the economical result of the fishery, helping the ship owners in the return of investment first, then in the future viability of the operation. Apart of the evident savings due to the fuel consumption reduction, in the long term, the ship owner will notice also savings on maintenance, both because the winches are towing with less tension (longer life for warps, brakes and hydraulic system) and the engine is running at low rpm's (longer life of the engine and between breakdowns). The new fishing gear does not require any modification on the way that the fisherman is working, only replacing and/or modifying some parts or components of the fishing gear. The implementation is easy and the adjustments required could be done in a couple of days.