Depaiwa, Nattawoot

Preferred name

Depaiwa, Nattawoot

Alternative Name

Depaiwa, N.

Main Affiliation

School of Engineering

nattawoot.de@kmitl.ac.th

Now showing 1 - 10 of 18

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Experimental investigation of the influence of ethanol and biodiesel on common rail direct injection diesel Engine's combustion and emission characteristics
(2022-11-01)
Wai, Phyo
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Kanokkhanarat, Phobkrit
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Oh, Ban Seok
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Wongpattharaworakul, Veerayut
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Depaiwa, Nattawoot
This study aims to characterize the effect of oxygenated biofuels in diesel engine combustion, thermal efficiency, and emission by blending different percentages of ethanol and biodiesel with fossil fuel derived diesel. In this research, 5% and 10% by weight of bioethanol were added to commercial B10 (10% biodiesel and 90% diesel), B20 (20% biodiesel and 80% diesel) and B100 (100% biodiesel) and experimented on using a 3 L four-cylinder common rail diesel engine. The experiment was performed under three engine speeds of 1000 rpm, 1500 rpm, and 2000 rpm with three constant engine torques of 56 Nm, 84 Nm, and 140 Nm. The results show that ethanol-biodiesel-diesel ternary blended fuels are higher in premixed combustion pressure and net heat release rate (NHRR) peaks. The cumulative heat release of ethanol blended fuels is also higher for ethanol blended fuels. The fuel consumption increased with the ethanol and biodiesel percentage in the blended fuels due to the lower heating value while the brake thermal efficiency did not decrease. It was clearly observed that the particle emission could be reduced by more than 50% when ethanol and biodiesel percentage increased.
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Thermal enhancement in a solar air heater channel using rectangular winglet vortex generators
(2010-01-01)
Depaiwa, Nattawoot
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Chompookham, Teerapat
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Promvonge, Pongjet
The forced convection heat transfer and friction loss behaviors for turbulent airflow through a constant heat flux channel solar air heater with rectangular winglet vortex generator (WVG) are experimentally investigated in this work. The rectangular winglet pairs are considered with two different arrangements by pointing upstream (PU) and pointing downstream (PD) of the flow. Ten pairs of the WVGs with various attack angles (a) of 60°, 45° and 30° are mounted on the test duct entrance wall to create longitudinal vortex flows over the tested channel. Measurements are carried out for the rectangular channel air heater of aspect ratio, AR = 10 and height, H = 30 mm with the WVG height, b/H = 0.4 and a transverse pitch ratio, P/H = 1. The flow rate is in terms of Reynolds numbers based on the inlet hydraulic diameter of the channel ranging from 5000 to 23,000. The experimental results show that the solar air heater channel with rectangular WVG provides significantly higher heat transfer rate and friction loss than the smooth wall channel. The use of larger attack angle value leads to higher heat transfer rate and friction loss than that of lower one. The PD-WVGs performs higher heat transfer rate and friction loss than the PU one for similar operating conditions. In comparison, the largest attack angle (α= 60°) of the PDWVGs yields the highest increase in Nusselt number and friction factor while the lowest attack angle (α = 30°) of the PU-WVGs shows the best thermal performance.
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Thermal performance in a tubular heat exchanger with deltawinglets
(2018-08-14)
Tongyote, Pattarapan
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Promvonge, Pongjet
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Depaiwa, Nattawoot
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Jedsadaratanachai, Withada
The paper presents an experimental heat transfer enhancement study in a tubular heat exchanger fitted with delta-winglets. The experimental work was conducted by varying the airflow rate in the test tube having a constant wall heat-flux for turbulent regime, Reynolds number (Re) from 5200 to 23,000. Effects of three pitch ratios (PR=P/D=1.5, 2.0 and 3.0) and two attack angles, α = 45° and 60°, of the winglets at a single blockage ratio (BR=b/D = 0.15) on thermal characteristics are examined. The experimental results show that the winglet-inserted tube yields, respectively, the heat transfer, friction factor and thermal performance in the form of TEF around 1.99-4.08, 4.9-14.3 times higher than the plain tube and 0.85-1.85, depending on the operating condition.
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Flow stress determination of steel tube for hydroformability evaluation
(2013-08-01)
Boonpuek, P.
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Jirathearanat, S.
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Depaiwa, N.
This study aims to determine flow stress of a steel tube by using hydraulic bulge test. A new proposed analytical model for analyzing bulge shapes of hydroformed tubes is postulated. Bulge test apparatus designed using FEA simulation of hydroforming and STKM 11A steel tubes are used in the hydraulic bulge test. Bulge heights and internal pressures are measured during bulge testing. Tube thicknesses at vertex of a bulge shape are measured by a dial caliper gauge. Bulge curvatures and contact points are measured by taking digital photos of bulge shapes combined with measurement methods in CAD software. Effective stress-strain relationships are obtained from the newly developed analytical model using those measured values. Flow stress curves obtained from the effective stress-strain relationships are compared with those by other researchers and tensile test. Finite element analysis methods are used to conduct simulation of tube hydroforming using the flow stress curves. Predicted internal pressures versus bulge heights and tube thicknesses are compared with experimental results. Verification of the developed analytical model is presented. The flow stress at neck point of the formed tube is determined. © 2013 American Scientific Publishers All rights reserved.
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Adaptive PID for controlling a quadrotor in a virtual outdoor scenario: Simulation study
(2013-11-25)
Moonumca, Pisan
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Yamamoto, Yoshio
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Depaiwa, Nattawoot
The main purpose of this paper is to develop a robust control methodology for unmanned aerial vehicles such as a quadrotor. A conventional proportional-integral-derivative (PID) controller is augmented with adaptive K<inf>P</inf> or non-adaptive K<inf>P</inf> in a throttle input and the both cases are compared and analyzed. Adaptive K<inf>P</inf> is suitable for a system which is subjected to parameter uncertainty, such as variation in payload or wind speed, as the algorithm is able to adjust the K<inf>P</inf> gain of the PID controller so that they maintain robustness and performance. The performance results of the two controllers when applied to a quadrotor are demonstrated using numerical simulation. © 2013 IEEE.
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Investigation of the Impact Bioethanol Blends into Biodiesel on Combustion Characteristics, Engine Performance, and Emissions of Diesel Engine
(2022-01-01)
Kanokkhanarat, Phobkrit
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Depaiwa, Nattawoot
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Karin, Preechar
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Wongpattharaworakul, Veerayut
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Srisurangkul, Chadchai
Emissions from a diesel engine are dangerous to the environment and human health. Substitutable fuels from a renewable source are one of the alternatives to reduce emissions. Neat biodiesel from based palm oil (B100) can reduce emissions from higher oxygen content to be more complete combustion. The disadvantage of neat biodiesel is lower thermal efficiency from an advancement ignition. To improve this problem, adding bioethanol produced from agriculture products into neat biodiesel by weight ratio as B100E5 (95% B100 with 5% bioethanol) and B100E10 (90% B100 with 10% bioethanol). Hence, the focus of this research is to examine the combustion and emission characteristics, including engine performance, of bioethanol blends into neat biodiesel fuels (B100E5 and B100E10) compared with neat biodiesel (B100). All samples were tested at an engine load of 140 NM with constant engine speeds of 1000, 1500, and 2000 RPM on a diesel engine. The results of bioethanol blends into biodiesel fuels indicate that the pressure in the combustion cylinder and rate of heat release increase with increasing percentages of bioethanol. B100E10 shows the highest brake thermal efficiency. The smoke intensity of bioethanol blends into biodiesel fuels is reduced by more than 50% when compared to neat biodiesel fuel, and higher NOx emission from higher oxygen content in the fuels.
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The force tracking control of electro-hydraulic system based on particle swarm optimization
(2016-01-01)
Moonumca, Pisan
;
Depaiwa, Nattawoot
This paper presents the optimal gains of backstepping controller by using the particle swam optimization technique. The mathematical model is developed by Newton’s second law, compressible fluid flow and flow rates of valve. The control law is formulated by employing a Control Lyapunov Function. The core feature of this paper is the combination of the backstepping and particle swam optimization for optimal performance of controller. The controller gains are determined in automatic selection gains by minimizing the integral of time multiplied by absolute error function on step input. The fitness value can be guaranteed to the convergence of controller gains. The implementations are separated into two cases which are the real and estimated state feedbacks. The experiment has illustrated to find optimal controller gains. The results are also compared with the tracking response of real and estimated state measures in step and square signal. The results show a better tracking performance by using the strong particle swarm optimization (PSO) algorithm.
1
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Tuning PID controller using genetic algorithms for electro-hydraulic system with tracking force control
(2014-01-01)
Moonumca, Pisan
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Depaiwa, Nattawoot
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Yamamoto, Yoshio
The aim of this paper is design a controller for force control of an Electro-Hydraulic System and selection of a PID gains are using genetic algorithm. The mathematical model is considered as the Newton second law and compressible fluid flow theory. This paper compares two kinds of tuning methods for PID controller. One is the controller design by the genetic algorithm, second is the controller design by the Ziegler and Nichols method. Each PID gains are tested with step input function, square signal, half-sine signal and half-saw signal. And results show performance index with rise time, settling time and Maximum %OS. It was found that the proposed PID gains tuning by the genetic algorithm is better than the Ziegler & Nichols' method. © (2014) Trans Tech Publications, Switzerland.
1
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A Directional Control Auxiliary Thrust System to Increase the Forward Speed of a Quadcopter UAV
(2024-01-01)
Srijun, Chanapan
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Depaiwa, Nattawoot
This research introduces a method to increase the horizontal speed of a quadcopter UAV using an auxiliary thrust system that can be adjusted in direction. The researcher used thrust vectoring control to align the thrust direction with the unmanned aircraft's longitudinal axis. A method for controlling a device mechanism using a proportional-integral-derivative (PID) control system. Based on the test results, it has been concluded that the Ziegler–Nichols Method in P controller, the Ziegler–Nichols Method in PD controller, and the Trial-and-Error method in PID controller are the most effective methods for maintaining system stability and achieving the setpoint. It took 0.693, 1.441, and 0.563 seconds respectively to reach the desired value. The researcher used computational fluid dynamics and equations of motion to simulate a UAV's speed. The simulation results of using 25% additional thrust while moving at a 2-degree angle showed that the unmanned aerial vehicle's speed increased by 35.3% compared to the unmanned aerial vehicle without the auxiliary thrust system. When the pitch angle was increased to 5 degrees, the speed of the UAV increased by 15.9%. At higher pitch angles of 10 degrees, the UAV's speed increased by 6.86%. Finally, at pitch angles of 15 degrees, the speed of the UAV increased by 4.97%.
2
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Tool path planning technique for robot plasma spray coating on duct component
(2010-12-01)
Aroonchote, Nattapon
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Naksuk, Nirut
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Depaiwa, Nattawoot
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Yamaura, Hiroshi
The internal plasma spray coating process for multisection shapes tubular, which has been applied by multi-axis robot station, is difficult to generate collision-free tool path manually. Robotic software is very helpful to create a tool path. At this point, a plasma flame should be perpendicular to the coating surface and there should be adequate spraying distance, from 3D CAD model. However, the constraints of both shape and size of spray gun and the tubular cause the collision to occur in certain positions on the motion path. The collision between the tubular with robotic parts or any part of the system is strictly prohibited. Therefore, this thesis studies on collision protection system to detect spraying point on the tool path which is the cause of collision. Furthermore, the researchers find tool path adaptation algorithm in order to automatically modify the spraying point to flee from collision. Moreover, the application also retains a spraying condition to keep the coating surface good as well.
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Depaiwa, Nattawoot

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