steady state test
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Author(s):  
Rupert Karlo D. Aguila ◽  
Edwin N. Quiros ◽  
Jose Gabriel E. Mercado

Abstract For the past years, Different Philippine local regulations have been imposed to address oil importation and to address environment concerns. One requirement is reduced emission from diesel engines and at the same time reduce the use of fossil fuels for the. In accordance to the Clean Air Act and the Biofuels Act, The Philippine government is looking for possible alternatives to fossil fuels, One of the biodiesel the country is currently using is coconut methyl ester due to the abundance of coconut trees in the country. This research shows the performance and emission characteristics of diesel blended with coconut methyl ester in a CRDi Passenger van and will help the government justify the increase in blend percentage mandated in commercial fuels. This study is investigates 0%, 2%, 5% 10% and 20% Coconut Methyl Ester (CME)-diesel blends. The experiment consisted of Japanese 10-15 standard drive cycle test, steady state test at 40,60, & 80 kph was performed in the Vehicle Research and Testing Laboratory in the University of the Philippines Diliman equipped with chassis dynamometer, fuel flow meter and emissions analyzer. Performance parameters measured are Power, Specific Fuel Consumption and Mileage, while emission characteristics for CO, NOx, THC are measured. PM measurements were not measured for this experiment. In both Drive cycle and steady state test specific fuel consumption and mileage improved with addition of CME, however results showed they are independent of CME percentage. The best improvement was observed with 5%CME blended with neat diesel at 4.8% and 8.5% for drive cycle and steady state test respectively. Majority of the CME-diesel blends showed decrease in emission specifically in CO and THC emission which is consistent to published literature. For both steady state test and drive cycle test up to 29.5% decrease inn CO and up to 64% decrease in THC was observed. This can be attributed to the overall lean mixtures and in the increase of oxygenated fuel at higher CME blends. NOx emission however is consistent for all fuel blends in the drive cycle test while for the steady state test NOx emission is dependnt on the engine speed. Decreasing trend was obtained for 40 and 60 km/h while increasing trend was obtrained at 80 km/h, with respect to %CME. Average power produced for all the speeds was basically constant for all the blends as compared with neat diesel. Lastly, maximum power showed insignificant changes although majority of the blends showed a minimal power reduction as compared to neat diesel.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1138 ◽  
Author(s):  
Abdul Abdul Ali ◽  
Nurul Ahmad ◽  
Normiza Mohamad Nor ◽  
Muhd Reffin ◽  
Syarifah Amanina Syed Abdullah

In many publications, the characteristics of practical earthing systems were investigated under conditions involving fast-impulse currents of different magnitudes by field measurements. However, as generally known, in practice the transient current can normally reach several tens of kiloamperes. This paper therefore aimed to investigate the characteristics of a new electrode for grounding systems under high current magnitude conditions, and compare it with steady-state test results. The earth electrodes were installed in low resistivity test media, so that high impulse current magnitudes can be achieved. The effects of impulse polarity and earth electrode’s geometry of a new earth electrode were also quantified under high impulse conditions, at high currents (up to 16 kA).


Author(s):  
Paul T. Semones ◽  
H. Alex Roberts ◽  
David A. Renfroe

EI Consultants (formerly The Engineering Institute) has been studying solid rear axle tramp for well over a decade, and contributed several publications to the literature outlining recommended test methods and their results. Throughout the history of EI’s research, sustained tramp inputs have been achieved by use of a tire featuring affixed lumps of rubber to induce wheel hop at one end of the axle. The principal methodological guide for studying the vehicle response to this input has been the test methods and data analysis recommendations of test standard SAE J266: Steady-State Directional Control Characteristics for Passenger Cars and Light Trucks. More specifically, past testing has been patterned almost exclusively on the circle test (constant-radius/slowly-increasing-speed) method discussed in J266. Historically, the J266 recommendation for data analysis and presentation, i.e. understeer/oversteer gradients derived from a wheel angle versus lateral acceleration plot, were principally used. Recent research, along with fresh analysis of previous testing results, revealed limitations of the circle test and the J266 recommended manner of data analysis in the context of tramp resonance testing. During a constant-radius/slowly-increasing-speed test, a single control variable (speed) has the effect of changing both the lateral acceleration and the tramp input frequency simultaneously. This effect results in a non-steady-state test event where only a narrow portion of each test run expresses the resonant axle tramp phenomenon that is the intended object of the observation. To provide a wider view of vehicle response characteristics during sustained axle tramp, EI Consultants selected and evaluated expanded test methods in a recent testing project. These methods included performing circle tests at multiple radii, performing continuous tests modeled after the J266 constant-speed/variable-radius method, and performing path-following tests modeled after the slowly increasing steer method. Expanded data analysis and presentation methods were developed to quantify and understand the vehicle oversteer response in more effective ways than those recommended by J266. Due to the abrupt discontinuity in the vehicle’s response upon reaching the resonant tramp frequency, novel methods of data presentation were shown to be more useful in assessing vehicle characteristics during resonant tramp. Of particular value was examining the steering input delta in the vehicle speed and tramp input frequency domains during the phase of resonant axle response; and examining the difference between the actual yaw rate and the theoretical Ackerman yaw rate derived from the measured steer angle. This paper will detail the data analysis techniques that were developed to overcome the limitations of the J266 standard’s steer gradient methodology, and thus introduce a more useful approach to evaluating understeer/oversteer characteristics during non-steady-state test events. This paper is the first of two companion papers presenting theory and results from EI Consultants’ most recent axle tramp testing. This paper focuses on new understandings of test data analysis theory, while the second paper will summarize the results of numerous tests and their application to various suspension design strategies for improving solid rear axle tramp control, with a motivation for enhancing vehicle controllability and highway safety.


2014 ◽  
Vol 960-961 ◽  
pp. 1006-1012
Author(s):  
Bao Shun Zhang ◽  
Cheng Yong Zhao ◽  
Chun Yi Guo ◽  
Li Zhuan Zhou ◽  
Lin Li

Compared with Line-Commutated-Converter High Voltage Direct Current (LCC-HVDC), the primary and secondary systems of modular multilevel converter based HVDC (MMC-HVDC) are more complicated. And control and protection function of sub-module controller (SMC) have great influence on the operation of MMC-HVDC system. This paper investigates the design method of SMC and sub-module (SM) steady-state platform. First, the structure of the primary system and the electrical parameters of the 21-level MMC-HVDC are designed. Second, the architecture of the control system and SM fault protection strategy are proposed, and the control program is developed and debugged. Then SM steady-state test platform and the relevant control and protection are designed. Finally, the steady-state test and the system test of the physical MMC-HVDC simulation system are conducted. The test result shows that the sub-module is of good property and SMC can communicate with upper control layer efficiently, control and protect the SM efficiently.


Author(s):  
Takao Kondo ◽  
Kazuaki Kitou ◽  
Masao Chaki ◽  
Yukiharu Ohga ◽  
Takeshi Makigami

Japanese national project of next generation light water reactor (LWR) development started in 2008. Under this project, spectral shift rod (SSR) is being developed. SSR, which replaces conventional water rod (WR) of boiling water reactor (BWR) fuel bundle, was invented to enhance the BWR’s merit, spectral shift effect for uranium saving. In SSR, water boils by neutron and gamma-ray direct heating and water level is formed as a boundary of the upper steam region and the lower water region. This SSR water level can be controlled by core flow rate, which amplifies the change of average core void fraction, resulting in the amplified spectral shift effect. This paper presents the steady state test with varied SSR geometry parameters, the transient test, and the simulation analysis of these steady state and transient tests. The steady state test results showed that the basic functioning principle such as the controllability of SSR water level by flow rate was maintained in the possible range of geometry parameters. The transient test results showed that the change rate of SSR water level was slower than the initiating parameters. The simulation analysis of steady state and transient test showed that the analysis method can simulate the height of SSR water level and its change with a good agreement. As a result, it is shown that the SSR design concept and its analysis method are feasible in both steady state and transient conditions.


2011 ◽  
Vol 32 (11) ◽  
pp. 845-850 ◽  
Author(s):  
A. Legaz-Arrese ◽  
L. Carranza-García ◽  
E. Serrano-Ostáriz ◽  
J. González-Ravé ◽  
N. Terrados

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