scholarly journals Pengaruh perubahan sudut camshaft terhadap performa mesin sepeda motor sebagai upaya efisiensi energi

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Lukito Dwi Yuono ◽  
Eko Budiyanto
Keyword(s):  
Combustion Chamber ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Exhaust Valve ◽  
Compression Pressure ◽  
A Value ◽  
Valve Opening ◽  
Motorcycle Engine

The role of the camshaft (noken as) is very important, including determining the time to open the valve, regulating the length of the valve opening duration, determining the overlap inlet and exhaust valve duration, as well as being a major component of the engine's working system. Modification of the camshaft angle is expected to be able to increase the efficiency of the combustion of fuel entering the combustion chamber and increase compression pressure in the combustion chamber so that it can improve volume quality of fuel entering the combustion chamber and can provide greater power to the engine rotation when in use. The purpose of this study was to determine the effect of camshaft angle changes on motorcycle engine performance and determine the effect of the camshaft duration on fuel consumption. The method that will be used in this research is to provide variations in angular changes on the camshaft of 20, 40, 60.Then test the dyno test on each variable. The result, the highest torque is the camshaft 40 variation with a value of 8.25 Nm. The highest power is in variation 40 with the highest number of 8.76 PS. Acceleration with the fastest time is obtained in camshaft 40 variations with a time of 14.2 seconds at a speed of 100 km/h. As well as the most efficient fuel consumption is at variation 20 with 150 ml fuel consumption.Keywords: Angle, camshaft, and engine performance.

Diesel Engine Performance Improvement for Constant Speed Application Using CFD

2017 ◽  
Author(s):  
Balasaheb S. Dahifale ◽  
Anand S. Patil
Keyword(s):  
Combustion Chamber ◽  
Fuel Consumption ◽  
Performance Improvement ◽  
Test Data ◽  
Engine Performance ◽  
Exhaust Valve ◽  
Fine Tuning ◽  
Intake Valve ◽  
Valve Seat ◽  
Load Conditions

The detailed investigation of flow behavior inside the combustion chamber and performance of engine is most challenging problem due to constraints in Experimental Data collection during testing; However, Experimental testing is essential for establishment of correlation with CFD Predictions. Hence, the baseline engine was tested at different load conditions and validated with CFD results, before it was optimized for performance improvement. The objective of the CFD Prediction was not only to optimize performance (Fuel Efficiency, Power, Torque, etc.) & Emissions Reduction, but also to assess feasibility of Performance Upgrade Potential. In the present CFD study, surface mesh and domain was prepared for the flame face, intake valve, intake valve seat, exhaust valve, exhaust valve seat and liner for closed volume cycle, between IVC and EVO using CFD code VECTIS. Finally simulations for three different load conditions were conducted using VECTIS solver. Initially, in-cylinder pressure vis a vis crank angle prediction was carried out for 100%, 75% and 50% load conditions. Then the fine tuning of (P-ϴ) diagram for different load conditions was conducted by varying different combustion parameters. Further, the engine performance validation was carried out for rated and part load conditions in terms of, IMEP, BMEP, break specific fuel consumption and power output, while NOx mass fractions were used to convert the NOx to g/kWh for comparison of emission levels with the test data. Finally optimized re-entrant combustion chamber and modified valve timing with optimum fuel injection system simulation was carried out to achieve target performance with reduced fuel consumption. A 3D CFD result showed reduction in BSFC and was in close agreement with the test data.

scholarly journals Analysis of the Influence of Local Politics on Implementation SDGs 4 Policy for Quality Education

2021 ◽  
pp. 196-204
Author(s):  
Wilda Rasaili ◽  
Dafik Dafik ◽  
Rachmat Hidayat ◽  
Hadi Prayitno
Keyword(s):  
Policy Implementation ◽  
Local Politics ◽  
Local Level ◽  
Quality Education ◽  
Local Democracy ◽  
Public Meetings ◽  
A Value ◽  
Political Interests

SDGs-4, the quality education is one of the factors in achieving the goals of the SDGs. The problem is that the SDGs look ambitious in integrating local level policies that are responsive to political interests. The research used a mixed method of exploration, searching for interview data and questionnaires. The results showed that the implementation of the SDGs was strongly influenced by local democracy. The implementation of the promotion of SDGs requires strengthening local politics and democracy, including; the quality of the Pilkada, the role of the community, political parties, media control, and public meetings. The influence of local democracy on policy implementation is 51.5%. Policy implementation has a positive effect on the implementation of the SDGs with a value of 0.187. The influence of local democracy and policy implementation on the promotion of SDGs-4 is 64.2% and the remaining 35.8% is influenced by other factors.

scholarly journals Peran Kepala Sekolah Dalam Mengembangkan Mutu Budaya Organisasi

2018 ◽  
Vol 2 (2) ◽  
pp. 407
Author(s):  
ZM Abid Mohammady
Keyword(s):  
Organizational Culture ◽  
Field Research ◽  
Education Institution ◽  
Quality Of Education ◽  
A Value ◽  
Qualitative Descriptive ◽  
The Impact

Abstract: In the context of Indonesia, the quality of education seems to be something taboo to talk about, however, according to researchers the quality of education in Indonesia is very apprehensive. It is necessary for the role of headmaster and special efforts in developing a quality education institution through organizational culture as a value system that is understood, imbued, run jointly by members of the organization as a system of meaning or guidance for the organizers. This study aims to describe the three roles and impacts role of the headmaster role in developing the quality of organizational culture, they are: (1) the role of the headmaster as a manager; (2) the role of the headmaster as the educator; (3) the role of the headmaster as the supervisor; 4) The impact of the headmaster's role in developing the quality of organizational culture quality at SDMT Ponorogo. This research is categorized into a field research with qualitative descriptive approach and the research design was case study. The setting of study was at SDMT Ponorogo.  The findings showed that (1). The role of headmaster as manager encompasses conducting internal and external analysis, internalizing the Islamic value that is kemuhamadiyahan value. (2). The role of the headmaster as an educator includes involving educators in upgrading, workshops or training in order to provide opportunities for educators to improve their knowledge and skills by learning to the higher education, conducting cadre to members of organizational culture and creating jargon to motivate members of organizational culture. (3). The role of the headmaster as a supervisor comprises overseeing and Evaluating the performance and achievement of members of organizational culture, conducting weekly, monthly and semester meetings, monitoring achievements of educators and learners. (4) The impact of the school headmaster's role in developing the quality of organizational culture is organizational culture climate becomes harmonious and schools achieve more attainments.Abstrak: Dalam konteks Indonesia, mutu pendidikan seolah-olah menjadi barang yang tabu untuk diperbicangkan, dalam konteks tersebut kualitas pendidikan di Indonesia sangat memperihatinkan. Untuk itu diperlukan peran kepala sekolah dan Upaya khusus dalam mengembangkan sebuah mutu lembaga pendidikan melalui budaya organisasi sebagai sistem nilai yang dipahami, dijiwai, dijalankan secara bersama oleh anggota organisasi sebagai sistem makna atau pedoman bagi pelaku organisasi. Penelitian ini bertujuan untuk mendeskripsikan dan menjelaskan tiga peran serta dampak peran  kepala sekolah dalam mengembangkan mutu budaya organisasi, yaitu: (1) Peran kepala sekolah sebagai Manajer, (2) Peran kepala sekolah sebagai Educator, (3) Peran kepala sekolah sebagai supervisor, dan (4) Dampak peran kepala sekolah dalam mengembangkan mutu budaya organisasi di SDMT Ponorogo. Dengan menghasilkan temuan: (1).Peran kepala sekolah sebagai manajer diantaranya: melakukan analisis internal dan eksternal, menginternalisasi nilai keislaman yaitu nilai kemuhammadiahan. (2). Peran kepala sekolah sebagai educator diantaranya: mengikut sertakan pendidik dalam penataran, workshop atau pelatihan memberikan kesempatan kepada pendidik untuk meningkatkan pengetahuan dan keterampilannya dengan belajar ke jenjang pendidikan yang lebih tinggi, melakukan pengkaderan kepada anggota budaya organisasi. membuat jargon-jargon untuk memotivasi anggota budaya organisasi. (3). Peran kepala sekolah sebagai supervisor diantarnya: mengawasi dan mengevaluasi kinerja dan pencapaian anggota budaya organisasi, mengadakan rapat setiap, minggu, bulan dan semester, memantau prestasi pendidik dan peserta didik. (4) Dampak peran kepala sekolah dalam mengembangkan mutu budaya organisasi diantaranya: iklim budaya organisasi menjadi harmonis, sekolah menjadi lebih berprestasi.

Thermodynamics Cycle Analysis, Pressure Loss and Heat Transfer Assessment of a Recuperative System for Aero Engines

2014 ◽  
Author(s):  
A. Goulas ◽  
S. Donnerhack ◽  
M. Flouros ◽  
D. Misirlis ◽  
Z. Vlahostergios ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Fuel Consumption ◽  
Heat Exchangers ◽  
Engine Performance ◽  
Specific Fuel Consumption ◽  
Hot Gas ◽  
Research Activities ◽  
Aero Engine ◽  
Overall Efficiency ◽  
Aero Engines

Aiming in the direction of designing more efficient aero engines, various concepts have been developed in recent years, among which is the concept of an intercooled and recuperative aero engine. Particularly in the area of recuperation, MTU Aero Engines has been driving research activities in the last decade. This concept is based on the use of a system of heat exchangers mounted inside the hot-gas exhaust nozzle (recuperator). Through the operation of the system of heat exchangers, the heat from the exhaust gas, downstream the LP turbine of the jet engine is driven back to the combustion chamber. Thus, the preheated air enters the engine combustion chamber with increased enthalpy, providing improved combustion and by consequence, increased fuel economy and low-level emissions. If additionally an intercooler is placed between the compressor stages of the aero engine, the compressed air is then cooled by the intercooler thus, less compression work is required to reach the compressor target pressure. In this paper an overall assessment of the system is presented with particular focus on the recuperative system and the heat exchangers mounted into the aero engine’s exhaust nozzle. The herein presented results were based on the combined use of CFD computations, experimental measurements and thermodynamic cycle analysis. They focus on the effects of total pressure losses and heat exchanger efficiency on the aero engine performance especially the engine’s overall efficiency and the specific fuel consumption. More specifically, two different hot-gas exhaust nozzle configurations incorporating modifications in the system of heat exchangers are examined. The results show that significant improvements can be achieved in overall efficiency and specific fuel consumption hence contributing into the reduction of CO2 and NOx emissions. The design of a more sophisticated recuperation system can lead to further improvements in the aero engine efficiency in the reduction of fuel consumption. This work is part of the European funded research program LEMCOTEC (Low Emissions Core engine Technologies).

scholarly journals Camshaftless Technology on Internal Engines

2020 ◽  
Vol 5 (2) ◽  
pp. 118-123
Author(s):  
Van Viet Pham
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Control Valve ◽  
Internal Combustion ◽  
Exhaust Valve ◽  
Combustion Engines ◽  
Toothed Belt ◽  
Significant Performance ◽  
Exhaust Valves

Along with the development of internal combustion engines, camshafts have also been developed to optimize engine performance. In all types of internal combustion engines, the crankshaft is connected to the camshaft via a toothed belt, chain or pinion. When the crankshaft turns, the camshaft spins and opens and closes the intake and exhaust valve respectively. However, in this non-camshaft engine technology, each intake and exhaust valve will be integrated with an electronically controlled hydraulic pump unit. This system provides a unique ability to independently control intake and exhaust valves. For any engine load, load and discharge times can be programmed independently. The decision system is based on driving conditions, used to maximize performance or minimize fuel consumption and emissions. This allows a greater degree of control over the engine which in turn provides significant performance benefits. This article presents reviews of camshaftless technology developed by VALEO. It is a system that uses solenoid valves to open and close the valve. The solenoid valve will be mounted right on top of the valve inside the engine. The author can see that the technology using this electronic control valve will help reduce the fuel consumption of the engine.

scholarly journals PENGARUH INJEKSI AIR DAN PENGATURAN DERAJAT PENGAPIAN TERHADAP PENURUNAN KONSUMSI BAHAN BAKAR MESIN SEPEDA MOTOR

2017 ◽  
Vol 2 (1) ◽  
pp. 23
Author(s):  
Myson Myson
Keyword(s):  
Combustion Chamber ◽  
Water Injection ◽  
Combustion Pressure ◽  
Injection Process ◽  
Time Required ◽  
Motorcycle Engine

Water injection is a hydraulic technique of injecting water into the combustion chamber with the purpose to decrease the amount of fuel sipped by pistons during the expansion, and replaced it with water directly injected to combustion chamber. This water injection process also reduce temperature in combustion chamber . Besides degree of ignition is having a significant effect on quality of combustion earning. Angle of earlier ignition will cause increase of combustion pressure speed, which in turn makes pressure result of combustion in excelsior cylinder. But if degree of ignition in backs into,  hence time required by fuel for combustible become smaller and fuel can be combustible at outlet. Result from test conducted by moving forward degree of ignition and water injection done at honda mega- pro and honda supra fit showed that efficiency of engine can be improved. For motorbike Honda Mega- Pro result showed improved of specific fuel consumtion to torsion equal to 47,82% with treatment of water injection mixed with alcohol with ratio 60:40 at degree of ignition moved forward by 3 degree of at burden 1 KW (Kilo Watt). For Honda Supra Fit improved of specific fuel consumtion to torsion 25,14 % at treatment of water injection mixed with by alcohol at ratio 80:20 with degree of ignition is moved forward 5 degree of at burden 1 KW.Keyword : Water injection, degree of ignition, improved efficiency, motorcycle engine

scholarly journals Penggunaan Metode Kooperatif Picture And Picture Guna Meningkatkan Kualitas Pembelajaran

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Suryani Suryani
Keyword(s):  
Social Sciences ◽  
Learning Process ◽  
Teaching And Learning ◽  
Student Learning Outcomes ◽  
A Value ◽  
Level Of Activity ◽  
Quality Of Learning ◽  
Cooperative Methods

In the teaching and learning process of Social Sciences, many problems are carried out by the teacher. One of them is some students still rely on their teacher's activities in learning, so the role of students is still very lacking. Even thought, the teacher always involving students to play an active in learning process. In contrary, students assume that the subject of Social Sciences is very boring. So that this causes a low quality of learning in Social Sciences, especially in  SMP Negeri 21 Pontianak. This cases has tickled the writer to take the theme of research on picture and picture cooperative methods to improve the quality of learning and increase the interest and activity of students in teaching and learning activities in Social Sciences.As for the techniques used of data collection is through observation by teachers and collaborators. The research involved two cycles of 42 students. While the data analysis used description with percentage techniques. Furthermore the level of activity of students and teachers is expressed in the category of "very good", "good" or "moderate", while the success of using picture and picture cooperative methods is stated as "successful", "less successful", or "unsuccessful".The results of this reseacrh with picture and picture cooperative methods have been successful, which is showing indicated by an increase in student activity of learning because it has reached the specified criteria is 81% of students are actively involved, while teacher activities reach 86.53%, as well as student learning outcomes with a value of 78.57, where this shows that it is exceeding the KKM value of 72, with a percentage of completeness of 76%, which has exceeded the criteria of 75%.

scholarly journals Simulation research into the influence of the combustion chamber blowby on the efficiency of a diesel engine

2014 ◽  
Vol 158 (3) ◽  
pp. 73-79
Author(s):  
Grzegorz KOSZAŁKA ◽  
Michał GĘCA ◽  
Andrzej SUCHECKI
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Fuel Consumption ◽  
Engine Speed ◽  
Direct Injection ◽  
Engine Performance ◽  
Technical Condition ◽  
Maximum Torque ◽  
Simulation Research ◽  
Service Lead

Combustion chamber leakage, caused mainly by blowby, results in a reduced engine performance and higher fuel consumption. The blowby rate is, to some extent, determined by the design of the piston-ring-cylinder assembly (PRC) and the blowby rate varies throughout the life of an engine due to wear of the said assembly. The paper presents a quantitative evaluation of the influence of the combustion chamber blowby on the engine performance and fuel consumption on the example of two diesel engines: older generation naturally aspirated indirect injection diesel engine and a modern turbocharged direct injection engine. The assessment was made based on a simulation research using the AVL Boost software and the input data for the calculations were ascertained based on measurements performed on actual objects. The results have shown that a reduction of the blowby by half compared to the values occurring in engines of good technical condition would increase the maximum torque and power by approx. 0.5% for both investigated engines. The results of the simulation have also shown that increases in the blowby occurring in engines after long service lead to increased fuel consumption from 1% to 7% and the lower the engine speed and load the greater theses values.

46 HAS THE QUALITY OF VESSELS A VALUE IN THE TREATMENT OF GLIOBLASTOMA MULTIFORME? A STUDY ON THE ROLE OF GLUT1 IN NEOANGIOGENESIS

2012 ◽  
Vol 102 ◽  
pp. S15
Author(s):  
J.G. Eriksen ◽  
P. Borghetti ◽  
M. Horsman ◽  
H. Skovgaard-Poulsen ◽  
B. Hasselbalch
Keyword(s):  
Glioblastoma Multiforme ◽  
A Value

Exhaust valve profile modulation for improved diesel engine curb idle aftertreatment thermal management

2021 ◽  
pp. 146808742096910
Author(s):  
Mrunal C Joshi ◽  
Dheeraj Gosala ◽  
Gregory M Shaver ◽  
James McCarthy ◽  
Lisa Farrell
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Thermal Management ◽  
Exhaust Valve ◽  
Outlet Temperature ◽  
Exhaust Manifold ◽  
Warm Up ◽  
Valve Opening ◽  
Active Regeneration ◽  
Negative Valve Overlap

Rapid warm-up of a diesel engine aftertreatment system (ATS) is a challenge at low loads. Modulating exhaust manifold pressure (EMP) to increase engine pumping work, fuel consumption, and as a result, engine-outlet temperature, is a commonly used technique for ATS thermal management at low loads. This paper introduces exhaust valve profile modulation as a technique to increase engine-outlet temperature for ATS thermal management, without requiring modulation of exhaust manifold pressure. Experimental steady state results at 800 RPM/1.3 bar BMEP (curb idle) demonstrate that early exhaust valve opening with negative valve overlap (EEVO+NVO) can achieve engine-outlet temperature in excess of 255°C with 5.7% lower fuel consumption, 12% lower engine out NOx and 20% lower engine-out soot than the conventional thermal management strategy. Late exhaust valve opening with internal EGR via reinduction (LEVO+Reinduction) resulted in engine-outlet temperature in excess of 280°C, while meeting emission constraints at no fuel consumption penalty. This work also demonstrates that LEVO in conjunction with modulation of exhaust manifold pressure results in engine-outlet temperature in excess of 340°C while satisfying desired emission constraints. Aggressive use of LEVO can result in engine-outlet temperatures of 460°C, capable of active regeneration of DPF at curb idle, without the significant increase in engine-out soot emissions seen in previously studied strategies.

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