Exhaust Channel Research Articles

ANALYSIS OF THE CAUSES OF CYLINDER HEAD FAILURE OF INTERNAL COMBUSTION ENGINES

The problem of failure of the cylinder head of an internal combustion engine is considered. The factors influencing the reliability of the cylinder head over a given service life are analyzed. Among the areas that suffer the most are considered: partition between valves and between the valve and the nozzle, exhaust channels, attachment points, the plane of the surface that is in contact with the block. An analysis of existing works was carried out. Usually, the issue of reliability of a separate zone is solved, about which you can find many articles and patents. To date, there are no known works that comprehensively consider the problem of the reliability of all problem areas related to the cylinder head. This work describes the nature of the influence on the stressed state of the cylinder head from various factors: temperature loads, loads from the pressure of the working body in the cylinder, loads arising during fastening. Ways to solve problems with the reliability of individual elements exist and are being solved by many researchers, but the expediency of their implementation is ambiguous. Thus, improving heat removal from the hottest surfaces can lead to an increase in the share of influence from other factors. Solving the problem of reliability requires comprehensive consideration and a comprehensive approach. Thus, when modernizing or developing a new design, it becomes mandatory to carry out a calculation study taking into account the most complete range of factors affecting the system, which combines all the constituent elements included in this node. Modern engineering analysis systems allow such studies to be performed. It is also important to have sufficient knowledge about the properties of materials, which significantly affects the quality of the results of calculation studies. The change in heat dissipation parameters over time can be taken into account with the help of boundary conditions, which will allow us to study how the cylinder head will behave after some time of operation.

Determining infrared radiation intensity characteristics for the exhaust manifold of gas turbine engine ТВ3-117 in МІ-8МSB-B helicopter

The object of this study is the screen-exhaust device in the TV3-117 engine of the Mi-8MSB-B helicopter. To reduce visibility in the thermal range, a system of mixing hot engine exhaust gases with ambient air is used; this technique makes it possible to reduce the infrared radiation of engines. For this purpose, a new sample of screen-exhaust device was designed for testing. A thermal imaging survey of the helicopter was conducted. Three variants of thermal images were acquired: a helicopter without installation of a thermal visibility reduction system, a helicopter with standard exhaust shields installed, and a helicopter with newly developed shield exhaust devices installed. Based on the obtained experimental results, the characteristics of the intensity of infrared radiation were determined for three variants of research in the range of thermal waves of 3–5 μm. The study uses a comprehensive approach to solving the tasks, which includes a statistical analysis of known and promising ways to protect a helicopter from guided missiles with infrared homing heads based on reduced radiation forces and a theoretical method for calculating flow and temperature fields. The advantages of placing the section of the exhaust channel of the designed screen-exhaust device in the horizontal plane for complete shielding of infrared radiation in the lower hemisphere have been experimentally proven. The benefits of directing the flow of exhaust gases from the screen-exhaust device into the space above the helicopter propeller and dividing this flow into four separate flows were shown. The results of experimental research could be used to design new or improve existing screen-exhaust devices by the developers of military aviation

Improved aerodynamic performance of the exhaust hood with triple-faced flange

For a local exhaust ventilation system to trap contaminants effectively, it is highly important to minimize its energy consumption without forgoing efficiency. Energy savings can be achieved by reducing the aerodynamic drag of non-straight elements of local ventilation systems. Goal of the study is to minimize the drag of an exhaust with a triple-faced flange by varying shelves lengths and tilt angles by the method of coordinated descent. Study conducted numerically and experimentally. For the first time a pattern of changes in LDC value depending on the size of the shelves was revealed. The minimum value of LDC is reached when the length of the first shelf adjacent to the exhaust channel is 0.5l (l -half width of the slot or radius of round exhaust hood), the angle of its inclination is 30°; the length of the second shelf is 0.7l with an angle of inclination of 90°; the length of the third shelf is 0.2l with an angle of inclination of 120°. The found velocity distribution shows the effectiveness of the exhaust hood capture. The reduction of the LDC, when compared with the typical exhaust hood with the flange inclined on 90° was 76 %, and compared with a real industrial exhaust hood from the welding table – 65.7 %. The outline of vortex zones at the entrance to the exhaust hood was determined by different methods. The findings can be used for the design and development of energy-saving slotted and round exhaust hoods.

E-Nose for Piston Ring and Cylinder Block Condition Detection of Motorcycle Engine Based on MyRIO LabVIEW Programming

This study has created a system capable of identifying the condition of the piston ring and cylinder block of a 4-stroke motorcycle engine using petrol or similar through exhaust emissions. Multisensory gas, sensitive to changes in CO, CO2, NOx, and HC gas elements and compounds, is installed as an input to the exhaust channel and integrated using LabVIEW programming on the NI myRIO module. Multisensory data is processed using the FFT and the backpropagation method to classify whether the piston rings and engine cylinder block are in good or damaged condition. Tests have been carried out on motorbikes with piston rings and engine cylinder blocks that are in good, damaged, or unknown condition. During the test, the target error value for motorcycles with piston rings and engine cylinder blocks in good or damaged condition is less than 1%. The system can distinguish the condition of the piston ring and cylinder block of a motorcycle engine that is 100% optimal and 100% damaged with an error of 0% compared to the compression test method, and the maximum error is 20% Compared to the technician's manual method. Ten motorcycles were randomly tested in unknown conditions; 50% were in good condition, and 50% were damaged. For further development, an electronic nose system can detect engine combustion conditions and damage to cylinder rings and 4-stroke motorbike engine blocks based on exhaust emissions.

Pengaruh Dimensi Saluran Buang dan Sudut Kipas Generator Terhadap Kinerja Perangkat Oscillating Water Column

This research aims to investigate the potential for optimizing ocean wave energy conversion using an Oscillating Water Column (OWC) device by focusing on the influence of variations in exhaust duct diameter and generator fan angle. Electrical energy, as a major need in Indonesia, demands exploration of renewable energy sources as an alternative to fossil fuels. Experiments were carried out by varying the exhaust duct diameter (5.5 cm, 4.5 cm, 3.5 cm) and generator fan angle (20°, 25°, 30°). The research results show that there is a significant influence of these two variables on OWC performance. The results of wind speed measurements show that with an exhaust channel dimension of 5 cm, the wind speed at an angle of 45° reaches 2.24 m/s, while at angles of 35° and 40° it is 0 m/s. In the same dimensions, increasing the exhaust duct dimensions increases the wind speed, with a dimension of 15 cm providing optimal results at all fan angles. Measuring the fan RPM in the exhaust duct dimensions (5 cm, 10 cm, 15 cm) shows that in the dimensions 5 cm and 15 cm, the fan RPM is 0 at an angle of 35°. Increasing exhaust duct dimensions, especially the 10 cm and 15 cm dimensions, provides a significant increase in RPM at 40° and 45° angles. The 15 cm dimension provides the best performance, especially at 45° angles. Voltage measurements at three angles (35°, 40°, 45°) with varying exhaust channel dimensions show that at dimensions of 5 cm and 15 cm, the voltage is 0 V at an angle of 35°. Increasing the fan angle, especially in the 10 cm and 15 cm dimensions, provides increased voltage. Dimensions 10 cm, at an angle of 45°, reaches the highest voltage of 24.68 V.

Development of thermoelectric exhaust energy recovery system of a hydrogen internal combustion engine in a city bus using a Three-Dimensional multiphysics model

In this study, individual thermoelectric generator (TEG) module was developed and validated through comprehensive analyses and experiments. A model of the TEG module was constructed and subsequently verified through a coherent alignment with experimental results, ensuring its viability and accuracy within the application of interest. A thermoelectric exhaust energy recovery (TEER) system designed with a robust rectangular structure was also developed for an urban mass transit bus, which operates using a hydrogen internal combustion engine. By accommodating 40 TEG modules, each complemented with cooling fins, and placing cooling channels at the top and bottom of the exhaust channel, it was demonstrated that a proportionality between the power output and load resistance of the TEER system through a dimensionless analysis. The system’s three-dimensional multiphysics model constructed concurrently with the actual system facilitated both optimization and validation, predicting an energy recovery of 1.0–1.1% from the hydrogen engine exhaust and an optimal load resistance of 3.2 Ω under various operating conditions.

(Poster Award - 1st Place) Liquid Water Permeability in a Hydrophobic Microporous Layer for the Anode Interdigitated Flow Field of a Gas-Liquid Separating Polymer Electrolyte Membrane Water Electrolyzer

A novel interdigitated flow field for polymer electrolyte membrane (PEM) water electrolyzers (polymer electrolyte electrolysis cells) composed of oxygen exhaust channels apart from liquid water feed channels has been developed for ground and space applications 1, 2). This design can separate oxygen gas and liquid water between the flow channels without buoyancy, so that it dispenses with water circulators for bubble removal in electrolyzers and external separators by natural or centrifugal buoyancy.In this electrolyzer, pressurized liquid water is injected in the in-plane direction from the water channels to the catalyst layer through a hydrophobic microporous layer (MPL) applied to the anode porous transport layer (PTL) 2). Produced oxygen gas is discharged in the through-plane direction of the MPL to the oxygen channels, taking advantage of the capillary pressure in the hydrophobic MPL 2),3). Extreme leakage of the liquid water to the oxygen channels has not been found.This study conducted liquid water permeability tests for an MPL (SIGRACET 29BC, SGL Carbon Inc.) with pressurized liquid water by weighing liquid water penetrated through the MPL-coated PTL to the PTL surface under ambient air pressure. We find gradual permeability decreases with time for different liquid water pressures 4). This permeability is a useful parameter for optimal structure designs of this electrolyzer. Similar tendencies were also observed for a hydrophobic PTL without MPL (SIGRACET 29BA, SGL Carbon Inc., substrate of the MPL-coated PTL). The same test on the hydrophobic MPL dried after the test revealed that the permeability partially recovered. The liquid water networks inside the MPL and the PTL substrate possibly lead to decreases in the permeability. This phenomenon is a critical issue for this electrolytic cell as well as PEM fuel cells, and thus discussed further.References1) Y. SONE, O.S. HERNANDEZ-MENDOZA, A. SHIMA, M. SATO, H. NAKAJIMA, H. MATSUMOTO, Water Electrolysis by the Direct Water Supply to the Solid Polymer Electrolyte through the Interdigitated Structure of the Electrode, Electrochemistry. 89 (2021) 138–140. https://doi.org/10.5796/electrochemistry.20-00145.2) H. NAKAJIMA, V. VEDIYAPPAN, H. MATSUMOTO, M. SATO, O.S. MENDOZA-HERNANDEZ, A. SHIMA, Y. SONE, Water Transport Analysis in a Polymer Electrolyte Electrolysis Cell Comprised of Gas/Liquid Separating Interdigitated Flow Fields, Electrochemistry. 90 (2022) 017002. https://doi.org/10.5796/electrochemistry.21-00097.3) H. Nakajima, S. Iwasaki, T. Kitahara, Pore network modeling of a microporous layer for polymer electrolyte fuel cells under wet conditions, J. Power Sources. 560 (2023) 232677. https://doi.org/10.1016/j.jpowsour.2023.232677.4) S. KUBOTA, H. NAKAJIMA, M. SATO, A. SHIMA, M. SAKURAI, and Y. SONE, Liquid Water Permeability Test for a Microporous Layer Applied to a Gas-Liquid Separating Polymer Electrolyte Membrane Water Electrolyzer, the 42nd Symposium of the Hydrogen Energy Systems Society of Japan (2022) 12H06.AcknowledgmentsThis study is based on results obtained from a project, JPNP21014, commissioned by the New Energy and Industrial Technology Development (NEDO).

Water Transport Modeling in a Microporous Layer for a Polymer Electrolyte Membrane Water Electrolyzer Having a Gas-Liquid Separating Interdigitated Flow Field

A novel interdigitated flow field design for polymer electrolyte membrane electrolyzers (proton exchange membrane water electrolysis cells), which has oxygen exhaust channels separated from pressurized liquid water feeding channels, has been developed for ground and space applications 1), 2). This structure separates oxygen and liquid water inside the anode of the cell. Thereby it dispenses with water circulators for bubble removal from the cell and external separators by natural or centrifugal buoyancy. We thus aim to develop a numerical model for further optimization of the cell design.Finite element modeling (COMSOL Multiphysics) of water transport is three-dimensionally conducted for the anode porous transport layer coated with a hydrophobic microporous layer (MPL) (SIGRACET 29BC, SGL Carbon Inc.) assembled with the interdigitated flow field. The MPL works to separate evolved oxygen gas exhausted in the through-plane direction and pressurized liquid water injected in the in-plane direction owing to the capillary pressure 2), 3). Prominent leakage of the liquid water to the oxygen channels has not been detected.Electrochemical kinetic parameters for the model are determined by electrochemical impedance spectra. Current-voltage measurement of the cell is also performed to validate the numerical modeling.We model the current densities and the current ratio between the reactant liquid water and water vapor at the interface between the MPL and catalyst layer (CL). The model involves fractional bubble coverage of the CL with produced oxygen gas and liquid water saturation in the MPL. The vapor evaporating from the liquid water in the MPL is assumed to be mixed with the evolved oxygen for diffusive water transport. The volumetric evaporation rate is assumed as a function of the liquid water saturation in the MPL.References1) Y. SONE, O.S. HERNANDEZ-MENDOZA, A. SHIMA, M. SATO, H. NAKAJIMA, H. MATSUMOTO, Water Electrolysis by the Direct Water Supply to the Solid Polymer Electrolyte through the Interdigitated Structure of the Electrode, Electrochemistry. 89 (2021) 138–140. https://doi.org/10.5796/electrochemistry.20-00145.2) H. NAKAJIMA, V. VEDIYAPPAN, H. MATSUMOTO, M. SATO, O.S. MENDOZA-HERNANDEZ, A. SHIMA, Y. SONE, Water Transport Analysis in a Polymer Electrolyte Electrolysis Cell Comprised of Gas/Liquid Separating Interdigitated Flow Fields, Electrochemistry. 90 (2022) 017002. https://doi.org/10.5796/electrochemistry.21-00097.3) H. Nakajima, S. Iwasaki, T. Kitahara, Pore network modeling of a microporous layer for polymer electrolyte fuel cells under wet conditions, J. Power Sources. 560 (2023) 232677. https://doi.org/10.1016/j.jpowsour.2023.232677.AcknowledgmentsThis study is based on results obtained from a project, JPNP21014, commissioned by the New Energy and Industrial Technology Development (NEDO).

Definition and evaluation of the gas exchange process of a two-stroke engine with external and internal mixture formation

Problem. The transition from external to internal mixture formation requires adjusting the organization of gas exchange processes. The subject of the research is the gas exchange indicators of the 1D 8.2/8.7 engine with spark ignition with a carburetor and direct fuel injection (DFI) for the organization of stratified fuel-air charge (SFAC) and stratified weak fuel-air charge (SWFAC). Goal. The purpose of research is to determine ways to improve cylinder cleaning from combustion products and increasing its filling with fresh charge at DFI. Methodology: the following methods were used to conduct a study of the engine according to the load characteristic (n = 3000 min-1) and determine the gas exchange indicators by the coefficients: consumption μ of the purge and exhaust channels; purge air leakage υ; residual gases γ; excess purge air φо; filling ηv; purging φ; use of purge air ηв; k.k.d. purge ηs. Originality. The empirical dependences of changes in gas exchange indicators: μ, υ, γ, φ, ηv on the load were determined. Results. With a carburetor power system γ = 0.24-0.17, φo = 0.32-0.67 (bmep = 0.174-0.45 MPa). At the maximum load (bmep = 0.45 MPa) ηv = 0.5. The use of a hemispherical symmetric combustion chamber with an increase in volume and load creates conditions for reducing γ and increasing ηs to 0.86. With DFI and the organization of the SFAC γ = 0.15-0.13 (bmep = 0.21-0.45 MPa), SWFAC γ = 0.16-0.13 (bmep = 0.144-0.21 MPa), γ = 0.4 (bmep = 0.43 MPa). In the case of SFAC and SWFAC, the maximum values of φо = 0.7 and ηv = 0.52 (bmep = 0.42–0.44 MPa). As the load decreases, the values of φо and ηv from the SWFAC exceed the values from the SFAC by up to 9%. The largest values of ηs = 0.87-0.88 (bmep = 0.21-0.47 MPa) correspond to the SFAC and the hemispherical combustion chamber shifted to the exhaust window. The organization of SWFAC in a hemispherical symmetric combustion chamber of smaller volume contributes to the reduction of ηs from 0.875 to 0.71. Practical value. In order to reduce γ and increase ηv at SWFAC, it is necessary to direct the flow of purge air inside the combustion chamber by installing an additional purge channel opposite the exhaust window.

Liquid Water Permeability in a Hydrophobic Microporous Layer for the Anode Interdigitated Flow Field of a Gas-Liquid Separating Polymer Electrolyte Membrane Water Electrolyzer

A novel interdigitated flow field for polymer electrolyte membrane water electrolyzers composed of oxygen exhaust channels apart from liquid water feed channels has been developed for ground and space applications. This design can internally separate oxygen gas and liquid water between the flow channels, dispensing with water circulators for bubble removal and external separators with natural or centrifugal buoyancy. In this electrolyzer, pressurized liquid water is injected in the in-plane direction from the water channels to the catalyst layer through the hydrophobic microporous layer (MPL) of the anode porous transport layer. The produced oxygen gas is discharged in the through-plane direction of the MPL, taking advantage of the capillary pressure in the MPL. This study conducted liquid water permeability tests on the MPL with pressurized water. We find gradual permeability decreases with time for different liquid water pressures. The permeability will be a useful parameter for the optimal structural designs of this electrolyzer.

Experimental study on heat transfer characteristics of the phase change chambers for heat flux enhancement

One promising way to increase the output power and the thermoelectric conversion efficiency of an automotive exhaust thermoelectric generator (TEG) is to add a phase change chamber between the exhaust channel and the thermoelectric (TE) modules with the chamber surface contacting with the exhaust channel where boiling occurs being larger than that with the module surfaces where the condensation occurs. The power is increased because a phase change chamber significantly increases the heat flux through the modules; thus, increasing the temperature difference between the module hot and cold sides. Although there is a significant body of literature on phase change chambers, most prior research has focused on chambers with larger condensation areas than boiling areas since they act as heat spreaders, while little is on chambers with condensation areas smaller than boiling areas for heat flux enhancement. These chambers have great potential to improve TEG power generation by enhancing the heat flux, therefore, more studies are needed to understand the chamber heat transfer characteristics. This research experimentally investigated the heat transfer characteristics of three chambers with condensation to boiling area ratios of 1/5, 2/5, and 3/5 for boiling heat fluxes from 4.50 to 22.70 kW/m2 and deionized water filling ratios from 33 to 50%. The results show that the boiling heat transfer coefficient increases with increasing heat flux or decreasing area ratio and is weakly influenced by the filling ratio. The condensation heat transfer characteristics depend on the distribution of droplets which is strongly affected by both the heat flux and the area ratio. The influence of the filling ratio on the condensation heat transfer coefficient increases with increasing area ratio. The thermal resistance of the chamber decreases with increasing heat flux and the lowest thermal resistance is obtained at 1/5 area ratio at lower heat fluxes and at 2/5 or 3/5 area ratio at higher heat fluxes.

Numerical Simulation of the Effect of Flow Velocity and Inlet Position on the Pressure Drop in the Exhaust Manifold

The exhaust manifold, also known as the exhaust header, is an important channel in the combustion chamber of a car. The exhaust manifold's role is to collect exhaust gas from various exhaust channels and direct it to the catalyst and car exhaust muffler for filtering. This research was conducted to see the pressure loss in the exhaust manifold at different speed conditions and different inlet positions on an engine with 4 cylinders. The speed variations used were 0.4, 0.6 and 0.8 m/s while the inlet position variations used were 1 and 3 and 2 and 4. The method used was numerical simulation. Geometry is created in the CAD software, then proceed with creating a mesh and setting boundary conditions. The results obtained show that the greater the flow rate, the greater the pressure drop. Based on the inlet position, positions 2 and 4 tend to have a greater pressure drop than positions 1 and 3 at each of the same speed. The largest pressure drop is 1.5438 Pa at a speed of 0.8 m/s with inlet channels 2 and 4.

The The Effectiveness Of The Pedestrian Path And Ramp On Jl. Imam Bonjol Corridor Semarang

Pedestrian paths and ramps are public facilities that are used by pedestrians and people with disabilities in accessing a place, moving from one place to another, connecting to a destination or carrying out other activities in urban space. Provision of pedestrian paths and ramps must be accessible, effective, and keep activities in urban spaces running well. One of the pedestrian and ramp lanes in Jl. Imam Bonjol corridor Semarang is interesting to study in which the existence of pedestrian paths and ramps can be said is still limited to providing public facilities without regard to quality, continuity of function of facilities and respect for users, both pedestrians and people with disabilities. However, the condition of the pedestrian paths and ramps in Jl. Imam Bonjol corridor is good enough, but there are some significant things that can hinder the user's circulation. Several sections of pedestrian paths and ramps are used as parking lots for vehicles, rickshaws and cars. The guiding line for the blind is cut off in several places and sometimes even leads to an open exhaust channel. In some sections it turns out to be difficult for the disabled to use it. This fact is very unfortunate because pedestrians and people with disabilities have the same rights in the use of pedestrian paths and ramps. This study aims to provide design solutions to the problem of designing pedestrian paths and ramps on Imam Bonjol Semarang street corridor to connect urban activity centers so as to provide an ease and convenience access and improve the quality of urban space. A qualitative descriptive method is used in this research, namely by describing the problem to be studied in more depth in order to find solutions and develop the findings of previous studies.

Exhaust heat recovery performance analysis of a Bi-fuel engine utilizing a thermoelectric generation kit and fuel economy evaluation

The internal combustion engine (ICE) exhaust gas temperature depends on fuel energy and combustion characteristics. The exhaust gas temperature of compressed natural gas fuel (CNG) is more than gasoline fuel and consequently, affect the thermoelectric generation (TEG) performance. This study evaluates how CNG and gasoline fuels affect exhaust temperatures, TEG power output and the brake specific fuel consumption (BSFC). In test setup, the engine exhaust channel is modified to support a thirty thermoelectric unit (TEM) in upper and lower of exhaust muffler; the TEM is clamped between exhaust mufflers and the cooling system to control the cold surface temperature of the TEM. The maximum power output and open circuit voltage of the TEG are described as functions of temperature difference. The electrical power output of the TEG is evaluated in terms of changing engine speed and load for both fuels. The result indicates that the CNG fuel has better temperature distribution of TEG Kit hot surface which can generate a maximum peak power output. The TEG kit can reach 178.3 W, while the gasoline fuel was 164.4 W. The average saving BSFC for a bi-fuel engine was (2.71%:3.20%) with TEG kit for both fuels.

Exhaust channel optimization of the automobile thermoelectric generator to produce the highest net power

The automobile thermoelectric generator is a promising energy conversion technology to enhance fuel economy and decrease the fuel consumption of vehicles. In order to boost the performance of the automobile thermoelectric generator, the fin distance and thickness of the heat exchanger are fully optimized according to a hydraulic-thermoelectric multiphysics model. The net power model of the automobile thermoelectric generator is established by factoring in weight loss, backpressure loss, and pumping power loss. It is found that the optimization of the fin thickness is primarily aimed at minimizing power loss, particularly backpressure loss, while the key parameter for determining the output performance is the fin distance. Based on optimization results, the optimal fin distance and thickness are 2 mm and 0.5 mm, respectively, resulting in a maximum net power of 45.02 W and a maximum net efficiency of 1.5%. By optimizing the fins of the automobile thermoelectric generator, significant improvements are observed in its performance, with output power, conversion efficiency, net power, and net efficiency increasing by 26.85%, 42.22%, 9.52%, and 22.95%, respectively, compared to the generator without fin optimizations. The results of this study are helpful to guide the design of the internal fins of the heat exchanger.

Pengaruh Penggunaan Catalytic Converter Kuningan Terhadap Emisi Gas Buang Mobil Antasari Evo I

Vehicles are a means of transportation used by humans to support their daily activities. Its growth rate is getting higher, making this situation one of the causes of air pollution. One of the options in reducing dangerous motor exhaust emissions is to use a catalytic converter. Catalytic converter is a device that is installed in the exhaust channel of vehicles. The purpose of this study was to determine the effect of using a catalytic converter with a 2 mm thick brass plate material on the exhaust emissions of CO2, CO and HC in the Antasari Evo I. The test was carried out by comparing the exhaust emissions produced by the standard exhaust and the exhaust that was installed with a catalytic converter based on variations in engine idle speed, 2000 rpm, 2500 rpm and 3000 rpm. From the results of the study it was found that the effect of using a catalytic converter with brass plate material placed on the exhaust gas channel can reduce the maximum CO2 emission level by 42,85%, reduce the maximum CO2 emission level by 83%, and reduce the maximum HC emission level by 18,4 %.

Studi Pengaruh Debit dan Jenis Runner Terhadap Efisiensi Turbin Vorteks PLTPH

Increased interest in the use of vortex turbines as a renewable energy source. more advantages compared to axial turbines in general. The aim of this applied research is expected to be able to increase the power and efficiency of vortex turbines, achieving the target efficiency output of >30% from the previous research output of 37% on the performance of single and two-stage turbines with an angle of 630. The research method is experimental based, the study being carried out at this time with variations in discharge and runner type 630 one stage and Savonius with exhaust channels cut off by 2cm, this was done to determine the response to increasing the efficiency of the vortex turbine. Experimental operational approach with SNI 8277:2016, discharge variation 11-13 l/s. The results of the experimental recording of the application of the runner 630 on one level, obtained that the highest efficiency was a flow rate of 11 l/s with an efficiency of 29%. The treatment of cutting the drain channel had an impact on reducing efficiency.

Analysis of the vibration caused by porting on the intake and exhaust channels of a 150 cc Kawasaki Ninja driver

Motorcycle vehicles are very popular because they are easy to maneuver and fast, so they are the most popular in various aspects of transportation in urban areas. However, motorbike drivers get tired easily. Acute fatigue, fatigue, chronic sleepiness, sleep disturbances, and heavy workloads have been associated with reduced performance in psychomotor tests and driving simulators and increased rates of motor vehicle crashes, injuries and deaths in certain populations. One that must be considered is the spread of vibrations originating from the piston motor. This is due to vibrations occurring in the work environment and distributed to the body of the workforce or objects in the workplace or work environment throughout the body in the form of mechanical vibrations originating from machines or mechanical equipment. Therefore, the purpose of this study will be to determine the effect of port placement on the intake and exhaust channels on vibrations throughout the body (Whole Body Vibration). Tissue resonance throughout the human body causes health problems. The standard or threshold value for the whole body vibration level that applies at the international level refers to ISO 2631. The test results on the driver’s arm with a rotational speed of 9900 rpm at the standard obtained a frequency of 6 Hz and an amplitude of 0.911137 mm/s2, after porting, the frequency is 7 Hz and the amplitude is 0.771992 mm/s2. Meanwhile, on the driver’s feet with a rotational speed of 9900 rpm, the standard obtained a frequency of 3 Hz and an amplitude of 12.0214 mm/s2, after porting a frequency of 3 Hz and an amplitude of 18.6765 mm/s2 was obtained. The results of this study can be concluded that the use of ports on motorbikes will cause riders to experience fatigue more quickly than standard motorbikes. Because the average ported has a greater amplitude than the standard conditions

Pengaruh porting saluran intake dan exhaust terhadap kinerja kawasaki ninja 2 tak 150 cc

After COVID, activities for motor racing championship competitions have increased year after year. As a result, an engine change is necessary to compete in motor racing events because utilizing a factory standard engine will not produce the best results. It basically has to be modified on the machine because factory standard machines have standard speed and are not ideal for the event motor racing. The goal of this study was to determine how intake and exhaust channel porting affected the 150 cc Kawasaki Ninja's performance and how the results varied in these areas. The experimental procedure entailed reshaping the intake and exhaust holes in the cylinder block from the intake port, which measured 44 mm to 42.5 mm from the upper lip, and the exhaust, which measured 36 mm to 41.5 mm, and exhaust height, which measured 35 mm to 29.5 mm from the upper lip of the cylinder block, a Dynojet test kit on a 150 cc Kawasaki Ninja 2 stroke motorcycle was used to determine the horsepower and torque data obtained. The results of the standard cylinder block data after porting adjustments to the intake and exhaust holes show that the torque results on the standard cylinder block get data from 19.31 at 6,723 rpm to 21.85 at 8,018 rpm, and the HP results on the standard block get data from 23.49 HP at 6,915 rpm to 27.92 HP at 8,584 rpm. The results of this investigation suggest that power and torque can be increased by changing the intake and exhaust ports. Engine performance will be impacted by increased power and torque. The process of adding ports to the intake and exhaust is only getting started with this research. Therefore, more study is required. In order to achieve the best power and torque outputs for the demands of motor racing, research can be conducted by creating porting adjustments

Experimental study of coupling heat transfer characteristics of boiling and condensation in an asymmetric phase change chamber

The output power of an automobile exhaust thermoelectric generator can be greatly improved by adding a phase change chamber with the condensation area smaller than the boiling area between the hot side of the thermoelectric modules and the exhaust channel. By decreasing the condensation area, the heat flux through the modules increases, which increases the temperature difference between the hot side and the cold side of the modules. Hence, the output power increases. However, the heat transfer characteristics of such kind of chamber with the confined space, the unequal boiling and condensation areas and the coupling interaction between the boiling and the condensation have not been fully studied. In this paper, the boiling and condensation heat transfer characteristics of deionized water in a chamber with the boiling to condensation area ratio of 5:2 were experimentally studied at boiling heat fluxes from 4.50 kW/m2 to 22.70 kW/m2 and filling ratios from 20% to 70%. The results show that the chamber total thermal resistance decreases and the temperature uniformity increases with increasing heat flux. The filling ratio has little effect on the total thermal resistance. The heat transfer coefficients obtained from the experiments were compared with those predicted by the correlations. The results show that the Cooper correlation (the deviation range of −41.3% ∼ − 9.7% from the experimental results), has a higher accuracy than the Rohsenow correlation (the deviation range of −73.6% to +43.9% from the experimental results) for predicting the boiling heat transfer coefficient. Neither the Nusselt correlation nor the Gerstmann-Griffith correlation can accurately predict the condensation heat transfer coefficients. Besides, the behavior of bubbles and condensate was observed during the experiment, explaining the variations of the boiling and condensation heat transfer coefficients versus heat flux.