Rotor Rpm Research Articles

Study of the Characteristics of Ship Propulsion Systems with the Addition of a Kort Nozzle using the CFD Method

The component of a ship that affects its speed the most is its propulsion system, which includes a propeller. The propeller produces thrust by converting the blades' rotating force. A well-functioning propulsion system increases the propeller's effectiveness, which enhances the ship's performance. The addition of a kort nozzle to the propeller is one of the numerous methods currently available for enhancing its performance. These justifications serve as the foundation for this investigation. The purpose of this study was to compare the propeller's operating efficiency with and without a koert nozzle addition. The result of the research it was detected that there was an increase in thrust force after using the cort nozzle under the influence of calm water and wavy water by 15 ~ 30%. There is an increase in efficiency under the influence of still water. But under the influence of waves the value is not great. The resulting efficiency value is approximately 3 ~ 5% for the same RPM rotation efficiency.

Perbandingan Tingkat Kebisingan Berbagai Bahan Peredam pada Knalpot Sepeda Motor Racing

The use of racing exhausts on motorised vehicles can cause uncomfortable and dangerous noise pollution if it exceeds the threshold set by the Minister of Environment. Based on the Decree of the Minister of Environment No 07/2009, the noise limit for motorbikes with engine capacity below 80 cc is 77 dB, 80-175 cc is 80 dB, and above 175 cc is 83 dB. This study aims to observe the comparison of noise levels of various silencer materials on racing motorbike exhausts in order to find the most effective material in reducing noise in accordance with these regulations. The noise measurement method follows the ISO 5130 standard, carried out when the engine is running idle and at engine speed range from 0 to 8000 RPM with a variety of different damping materials. The results show that at idle conditions, yellow Glasswool is the best damping material with the lowest noise level of 90.31 dBA, while Stainless wool shows the worst performance with an average noise level of 100.81 dBA. In contrast, in the 0-8000 RPM rotation condition, Stainless wool became the most superior silencer material with a noise level of 105.4 dBA, while grandma's hair Glasswool (fibreglass) became the worst with the highest noise level of 106.4 dBA. The conclusion of this study is that the optimal choice of silencer material can differ depending on the operating conditions of the racing exhaust, with yellow Glasswool being more effective at idle conditions and Stainless wool being more effective at maximum revs.

Achieving partial nitrification by sludge treatment using sulfide: Optimal conditions determination, long-term stability evaluation and microbial mechanism exploration

This study proposes an innovative strategy for achieving PN in synthetic domestic wastewater by side-stream sludge treatment using sulfide as the sole control factor. By conducting controllable batch experiments and response surface analysis, optimal sulfide treatment conditions were firstly determined as 90 mg/L of sulfide, 7.5 of pH, 100 rpm of rotation and 12 h of treatment time. After treatment, half of ammonia oxidizing bacteria (AOB) activity remained, but nitrite oxidizing bacteria (NOB) activity was barely detected. Nitrite accumulation rate of long-term running PN steadily reached 83.9 % with 99.1 % of ammonia removal efficiency. Sulfide treatment increased community diversity and facilitated stability of microbiota functioning with PN phenotype, which might be sustained by the positive correlation between ammonia oxidation gene (amoA) and sulfur oxidation gene (soxB). Correspondingly, the network analysis identified the keystone microbial taxa of persistent PN microbiota as Nitrosomonas, Thauera, Truepera, Defluviimonas and Sulitalea in the later stage of long-term reactor.

EFFECT OF IGNITION TIMING CHANGES ON EXHAUST EMISSIONS IN KEN AROK URBAN CAR FUELED BY ETHANOL E100

ABSTRACT The depletion of fossil fuel reserves, as well as the increasing air pollution that occurs in Indonesia, greatly affects the energy crisis. This study aims to test, analyze, and determine the right ignition timing and injection timing so as to reduce HC and CO exhaust emissions pollution with E100 ethanol fuel. The test method in this study uses ignition timing independent variables (10.5⁰, 12.5⁰, 14.5⁰, 16.5⁰) and is carried out at 1500, 2000, 3000, 4000 RPM engine speed. The results of this study can be seen that the ignition timing variable has an influence on HC and CO exhaust emissions. at 1500 RPM rotation, the lowest HC and CO exhaust emissions are obtained at 16.5⁰ ignition timing with a value of HC 260 ppm and CO 0.12%. Then for the highest exhaust gas results there is at 12.5⁰ ignition timing with a value of HC 310 ppm and CO 0.16%. Keywords: exhaust emissions, ethanol, ignition timing

Understanding Critical Aspects of Liposomal Synthesis for Designing the Next Generation Targeted Drug Delivery Vehicle

AbstractWe identified process parameters of the thin film hydration technique and intrinsic factors to synthesize liposomes for drug delivery. The thin film formation step impacted the nature of the lipid layer, and we optimized 240 RPM rotation speed, 700 mm of Hg vacuum pressure, and 2 ml of chloroform as the organic solvent. The hydration step controlled the particle specifications, and we optimized 270 RPM rotation speed, PBS as the hydrating medium, and 1 h hydration time. We obtained a comparatively smaller liposomal population with a lower size distribution just after hydrating the lipid layer that required milder downsizing steps −10 extrusion passes through a single polycarbonate membrane. The intrinsic factors including the concentrations and molar ratio of lipids affected the synthesis steps and the particle specifications. Characterization of liposomes by analytical techniques confirmed the synthesis of a monodisperse population with hydrodynamic diameter<150 nm, moderate stability, spherical morphology, and high thermal and storage stability. This comprehensive study defines the role of every parameter, provides a mechanistic insight into synthesis that is supported by experimental data, and helps tune specific parameters to synthesize liposomes for drug delivery or any application with desired specifications.

Experimental investigations and effect of parameters on friction welded AISI 304 and Invar alloys

ABSTRACT It is challenging to achieve sound weld quality between dissimilar materials such as AISI 304 and Invar alloys with the help of the fusion welding process due to various weld defects like slag inclusion and misalignment. In current work, Invar alloys and AISI 304 material is welded with 12 mm diameter and 70 mm length on a commercial friction welding machine. Taguchi L9 orthogonal design is utilised for experiments, and an optimised parameter combination is identified. Machining parameters such as friction rotation RPM − 1100,1300,1500 rpm, frictional pressure 33,43,53 MPa, and burn-off length 4,5,6 mm are selected for the experiments. Forge pressure is not applied in experimental tests, and the tensile strength of the weld joint is evaluated for comparison. The findings revealed that the lower friction pressure up to 43 MPa resulted in higher tensile strength up to 517 MPa and refined grains in the microstructure. The higher friction pressure resulted in lower tensile strength due to non-homogeneous temperature distribution at the weld interface. The burn-off length shows significant effects on tensile strength results beyond 5 mm. The findings demonstratedthat the process could join dissimilar materials with enhanced mechanical properties.

Design and Modeling of a Miniature Hydraulic Motor for Powering a Cutting Tool for Minimally Invasive Procedures.

Miniaturization of multifunctional instruments is key to evolving less invasive medical procedures. The current work outlines steps towards developing a miniature motor to power a cutting tool of a millimeter-scale robot/device (target outside diameter ~2 mm) for minimally invasive procedures. Multiple motor concepts were explored and ranked using a Pugh matrix. The single-rotor hydraulic design was deemed most viable for prototyping and scale-down to the target size. Prototypes were manufactured to be progressively smaller using additive manufacturing. The smallest prototype fabricated was 2:1 scale of the desired final size with a 2 mm outside diameter (OD) rotor and a device OD of 4 mm. The scaled prototypes with an 8 mm rotor were lab tested and achieved average speeds of 5000-6000 RPM at a flowrate of 15-18 mL/s and 45 PSI water pressure. Ansys CFX was used as a design tool to explore the parameter space and 3D transient simulations were implemented using the immersed solid method. The predicted rotor RPM from the modeling matched the experimental values within 3% error. The model was then used to develop performance curves for the miniature hydraulic motor. In summary, the single-rotor hydraulic design shows promise for miniaturization to the target 2 mm size.

Noise footprint assessment at a vertiport for different approach and departure procedures of a tilt-wing air-taxi

Community noise at vertiports is one of the most important questions related to upcoming urban air mobility (UAM) operations. While fixed-wing and/or fixed-rotor aircraft can mainly be treated by their changing operational parameters, such as rotor or propeller rpm, tilt-wing or tilt-engine configurations are more difficult to simulate because of their constantly changing noise emission and spatial radiation characteristics. The work presented in this paper is providing an overview of the noise situation at a virtual vertiport which is being approached and departed by a tilt-wing air-taxi in different ways. Several different departure procedures are simulated with the same generic air-taxi. For the noise emission semi-empiric methods were used. During the air-taxi's descent and climb, different tilt configurations are included, mainly defined by the time dependent engine's tilt-angle, but also related to different approach paths. Each approach or departure procedure is generating individually time dependent changing noise emission characteristics which are used for noise footprint mapping around the touch-down or lift-off point. Different noise metrics are computed, including some which are representative to indicate noise annoyance among the vertiport's neighborhood. It is expected that each procedure will generate its own specific community noise situation in the vicinity of the vertiport, and thus may provide an early recommenddation for later operations. The results are compared towards each other. Additionally, a simulated certification flyover according to ICAO Chapter 13 - which is about the noise certification of tilt-rotor aircraft - is set into relation to the vertiport's community noise.

Improved Gust Tolerance of a Cyclocopter UAV Using Onboard Flow Sensing

This paper describes the gust rejection study of a twin-cyclocopter micro air vehicle with two cyclorotors and an anti-torque nose rotor. A gust rejection controller relying on velocity feedback and onboard flow sensing was implemented in a closed-loop feedback system. Tethered experiments were conducted with the vehicle mounted on a 6-DOF stand in front of a synthetic gust generation device capable of providing up to 4 m/s step gust input. Planar gusts along the longitudinal and lateral axis of the cyclocopter and crosswinds were systematically studied. Both pitch control (varying nose rotor rpm) and thrust vectoring control strategies were evaluated to counteract perturbation along the longitudinal axis, while the cyclocopter used differential rotational speed of the cyclorotors for lateral gusts. Results showed that thrust vectoring was more effective than pitch control in reducing displacement from gust. Pitch control using the position feedback controller resulted in a maximum gust tolerance of 2.8 m/s with a duration of 3 s. while thrust vector control using the combined flow feedback and position feedback controller was able to withstand 4 m/s step gust input with 1 s duration with only 0.01 m displacement. In addition, flow feedback was more effective than position feedback in minimizing position error. The cyclocopter was also able to mitigate step gusts of 2.8 m/s in magnitude and 3 s duration with crosswind components at 30 deg from the longitudinal axis. The difference in performance can be attributed to the cyclocopter's unique thrust vectoring capability.

An Improved Metaheuristic Method-Based Neural Network for Predicting Wind Turbine Power

Wind power production has advanced rapidly in recent years as a supreme renewable energy source that is safe, reliable, pollution-free, and simple to integrate into the power grid. Furthermore, employing data acquisition and supervisory control to predict wind turbine power may not result in the best governing approach, as non-calibrated data may be generated due to sensor degradation. Hence, to solve the adverse impact, it’s planned to incorporate the wind turbine Supervisory Control and Data Acquisition (SCADA) data into the improved optimization based NN, resulting in the development of a highly accurate prediction model. Thus, SCADA data of the wind turbine such as active power, bearing shaft, gear box shearing, gear box oil temperature, generator rpm, generator windings 1 and 2, hub temperature, reactive power, rotor rpm and wind speed are fed as input features to the predictive model. In order to achieve better prediction, the NN will be trained by using a new Coefficient Factor Updated Coyote Optimization Algorithm (CFU-COA), which is the conceptual advancement of traditional Coyote Optimization Algorithm (COA). Finally, the supremacy of the presented approach is proved with respect to varied error measures.

An improved prediction of frictional pressure drop using an accurate shear rate equation for high-yield stress drilling fluids at the surface and downhole conditions

This paper evaluates a more accurate and relatively new shear rate equation based on the phenomenological model for the high yield stress drilling fluids to estimate frictional pressure drop in laminar and turbulent flow regimes under surface and downhole conditions. Fann viscometer readings are used to determine shear rates using the above phenomenological model that differ from the conventional shear rates, i.e., γ˙(s−1)=1.7N, where N = Fann viscometer rotor rpm. The new shear rates are used to predict model parameters of Bingham plastic (BP), power-law (PL), Herschel–Bulkley (HB), and Robertson-Stiff (RS) models, and corresponding frictional pressure drops. The efficacy of the above rheology models with improved model parameters is tested by validating the literature-reported experimental pressure drop data of low to high yield stress water-based drilling fluids. The validation results are consistent and accurately predict frictional pressure drops using HB and RS models with the lowest MSE-values. The above methodology is applied to predict frictional pressure drops in a pipe for ten test high-pressure, high-temperature (HPHT) drilling fluids of varying base fluids at the surface and HPHT conditions in laminar and turbulent flow regimes. For this, isothermal compressibility and thermal decomposition temperature of drilling fluids are measured to forecast the temperature- and pressure-dependent densities and shear viscosities. The proposed density model is experimentally validated and found to predict density at downhole conditions adequately with mean absolute- and standard-deviation, i.e., 1.67 and 1.36%, respectively. Temperature- and pressure-dependent viscosity and density have been used to predict pressure drop under downhole conditions using HB and RS models with improved model parameters from the phenomenological model. The HB model is found to be more accurate than the RS model for predicting pressure drop. The proposed frictional pressure drop estimation method in the present study is more general and accurate under the surface and downhole conditions than the conventional practice.

PENGARUH MODIFIKASI LUBANG BUANG TERHADAP DAYA DAN TORSI PADA SEPEDA MOTOR 2 TAK

Gasoline engine is one type of internal combustion engine that is widely used as a source of power for vehicles. Gasoline engines produce power from the combustion of fuel in the cylinders. In line with the development of science and technology, there are many improvements and developments of components to add power and torque. The purpose of this study was to determine the effect of modified exhaust cylinder block on power and torque on a 2 stroke Yamaha f1zr motorcycle with a modified exhaust hole height of 26 mm and a standard exhaust hole of 34 mm with a dynotest test to determine power and torque from 2500 RPM to RPM. 8000. The test results show that the maximum power at the modified exhaust hole is 12.5 HP at 7750 RPM while the standard exhaust port gets a maximum power of 11.5 HP at 7750 RPM. For the modified exhaust hole maximum torque is 11.36 Nm at 7750 RPM rotation while the standard exhaust hole obtains a maximum torque of 10.06 Nm at 7750 RPM rotation.Keywords: Power, torque, exhaust hole

Data-driven analysis and new findings on the loss of tail rotor effectiveness in helicopter accidents

Loss of tail rotor effectiveness (LTE) is an unstable dynamic phenomenon that affects single-rotor helicopters and frequently leads to accidents. LTE accidents recur with troubling regularity and show no sign of abatement. This work uncovers new data-driven findings pertaining to LTE and risk factors. First, a scorecard is developed covering a broad range of results to better understand LTE accidents. Second, the risk of LTE is derived for current helicopters. Third, a Deep Learning model is developed that captures the dependence between LTE risk and helicopter features. A danger zone is discovered in the design space for short tail rotor arm and high tail rotor RPM. The results challenge the prevailing narrative of LTE accidents as mere pilot errors and demonstrate an intrinsic propensity to these accidents is embedded in part in the helicopter design. The findings open the door to new, more effective safety interventions for LTE accident prevention.

Analysis of Flow Characteristics and Paracetamol Tablet Hardness Using 2D Double Mixer of Design Drum Type with Rotation and Mixing Time Variations

One of the tablet manufacturing processes using the wet granulation method is the process of mixing the active ingredient granules, fillers, binders and pelicans. The parameters of the mixing process are important to study because they will affect the physical properties of the tablet. This study studied the effect of the variable duration and the size of the mixing cycle on the physical properties of paracetamol tablets using a 2D double mixer. The results of the analysis and testing showed that the variation of mixing time and the size of the rotation had a significant effect on the flow properties of the granules and the hardness of the tablets. In addition, the optimal parameter results to obtain optimal tablet hardness occurred at 15 minutes of mixing process and 50 rpm of rotation.

Experimental study of air velocity effect of heat transfer in distillation condenser

A cooling tower is a heat exchanger equipment that uses water splashing media to lower the temperature by extracting heat from the water and emitting it into the atmosphere. Wind speed or velocity of wind waves is a fundamental atmospheric quantity caused by moving air from high pressure to low pressure while wind is moving air. Air velocity has an effect on the value of heat transfer coefficient, the faster the air, the better the value so that the heat transfer that occurs is also better. Research was also carried out on the human body to see forced convection due to the movement of these parts of the body, resulting in that the faster the body moves, the better the heat transfer coefficient value, this is related to the air flow that occurs on the body surface. The test shows that the more blower rotation make faster the heat transfer that occurs. At 2500 RPM rotation shows higher heat transfer by producing an average of 29.210 watts, the displacement decreases when the rotation is lowered to 1700 RPM to produce an average of 20.677 watts. The effectiveness of the tool by increasing the rotation from 1700 to 2500 by 32%.

The Effect of Additional Ethanol Steam Temperature Variations on Pertalite Fuel Use on Performance and Efficiency of 4 Stroke Motorcycles

The means of transportation that are widely used in Indonesia are vehicles in the form of motorbikes and cars, as well as the increasing dependence on the consumption of fuel oil (BBM). The impact is that the need for fuel oil is also high. As a result of dependence on fossil energy this one increases. Based on the problems that have been raised, a concept has emerged to make alternative fuels that can be used as a fuel mixture or as an alternative to these fuels. One of the renewable energy sources that can be utilized is ethanol which comes from corn, wheat, and others. ethanol vapor as a fuel mixture, where the ethanol used is not mixed directly into the fuel. And by utilizing ethanol vapor, it is also expected to increase the performance and efficiency of motorbikes. In this study we used a reference concept which was then used as a concept, how to influence additional ethanol vapor temperature variations on the use of pertalite fuel on the performance and efficiency of 4-stroke motorbikes using temperature variations of 400C, 500C, and 600C and variations of valve openings on the ethanol vapor hose to the intake manifold. After conducting the test, the results show that the best power is obtained from the addition of ethanol steam at a temperature of 450 full openings when it is at 7973 RPM rotation which shows a power of 31.2 HP and when it is at 5757 RPM rotation which shows a torque of 32.24 N.m. The best fuel efficiency is obtained from the addition of ethanol steam with a temperature of 450 full openings with a fuel consumption of 1 liter only reduced by 75 ml every 5 minutes of use at the same speed.

High performance of brain emotional intelligent controller for DTC-SVM based sensorless induction motor drive

This paper introduces the application of the induction motor (IM) drive brain emotional intelligent controller (BEIC). Intelligent regulation, modelled on the human brain, is capable of generating impulses and is used as a controller. A Model Reference Adaptive System is developed using stator current and stator voltages, which are further developed with BEIC to approximate the rotor rpm. This paper proposes that speed estimation using BEIC for direct torque control (DTC) of IM drive. The experimental work is conducted on a hardware-in-loop mechanism using a real-time digital simulator (Op-RTDS-OP5600). The simulation and test results are discussed. The proposed method is compared to the DTC-SVM-based IM drive speed control with the existing controllers.

Rotating acoustic source localization: A power propagation forward model and its high-resolution inverse methods

The rotating-acoustic source localization has played an important role in rotary machine fault diagnosis, engine noise reduction and propeller recognition etc. To achieve high-resolution localization of fast rotating sources, this paper proposes an improved power propagation forward model of rotating acoustic source based on the equivalent source hypothesis. Then the ill-posed inverse problem derived from the forward power model is solved robustly by proposed two sparsity-based methods: the Least Absolute Shrinkage and Select Operator for Rotating-acoustic Sources (LASSO-RS) and Least Angle Regression for Rotating-acoustic Sources (LAR-RS). The contributions of this paper are that, at one hand, the improved forward model is indeed time-invariant for the fast-rotating source owing to the time-domain de-Doppler technique; at the other hand, high-resolution acoustic maps can be obtained by proposed LASSO-RS and LAR-RS thanks to the sparsity-based regularization, even under very low signal-to-noise ratio (SNR). Moreover, the proposed LAR-RS is the data-driven method, rather than the parameter-dependent method such as the LASSO-RS with careful selection of regularization parameter. In simulations and experiments, the proposed methods can robustly localize rotating monopoles in the condition of 3000 RPM rotation speed (50 Hz), −5 dB SNR, and 2500 Hz working frequency.

Blade Structural Load/Airload Correlation on a Slowed Mach-Scaled Rotor at High Advance Ratios

To expand the cruise speed of a compound helicopter, alleviating the compressibility effects on the advancing side with reduced rotor RPM is proved to be an effective design feature, which results in high advance ratio flight regime. To investigate the aerodynamic phenomena at high advance ratios and provide data for the validation of analytical tools, a series of wind tunnel tests were conducted progressively in the Glenn L. Martin Wind Tunnel with a 33.5-inch radius fourbladed articulated rotor. In a recent wind tunnel test, the rotor blades were instrumented with pressure sensors and strain gauges at 30% radius, and pressure data were acquired to calculate the sectional airloads by surface integration up to an advance ratio of 0.8. The experimental results of rotor performance, control angles, blade airloads, and structural loads were compared with the predictions of comprehensive analysis and computational fluid dynamics (CFD) analysis coupled with computational structural dynamics (CSD) structural model. The paper focuses on the data correlation between experimental pressure, airload, and structural load data and the CFD/CSD predicted results at various collective and shaft tilt angles. Overall, the data correlation was found satisfactory, and the study provided some insights into the aerodynamic mechanisms that affect the rotor airload and performance, in particular the mechanisms of backward shaft tilt, the effect of hub/shaft wake, and the formation of dynamic stall in the reverse flow region.

Kajian Produksi Ball Mill Dalam Menentukan Efektivitas Penggerusan Bijih Timah Primer Di CV Persada Tambang Intitama TK 4.218 Paku Kabupaten Bangka Selatan

CV Persada Tambang Intitama TK 4.218 Paku is a partner company of PT Timah Tbk, which conducts primary tin mining using the open pit method. Primary tin ore processing includes comminution, sizing, and concentration activities. Grinding using a Ball Mill is an advanced process that aims to reduce the grain size of the material in order to obtain finer grain sizes (fine material) and prepare the right grain size for the concentration process of 80 s.d - 200 mesh. In this study, the variables used are feed rate, number of Ball Mill revolutions (RPM), and water rate. The experiment was used 27 times by setting variables in combination to get effective scouring results. The material at the study site is divided into high grade and low grade materials with primary tin mineralization types in the form of stanniferous veins and gossan formed due to the oxidation process of polymetallic veins. Variable feed rate, number of Ball Mill revolutions (RPM), and water rate are very influential on the results of grinding. The higher the feed rate, the number of turns, and the rate of water the higher the Ball Mill scour, but if the variable is too high it causes overload capacity so that the output volume decreases. The effectiveness of the grinding results obtained in sample 24 with the highest production value reaching 93.9%. The effective value is obtained from setting the feed rate variable 5 to 6 Ton Per Hour (TPH), 80 rotation RPM, and water rate of 10.800 liters/hour (l/h). The result of the maximum feed rate that can be done is 9.86 TPH with LPT is 236.64 ton/day. Thus, the average LPT target of the company's 230-240 tons/day Ball Mill can be achieved