Bangkok, Thailand

Mahanakorn University of Technology is a university in Thailand. The university was established on February 27, 1990 at Nong Chok District, Bangkok. as Mahanakorn College by Prof. Dr. Sitthichai Pookaiyaudom, former Dean of King Mongkut’s Institute of Technology Ladkrabang. The objective was to train engineering students in response to the severe shortage of engineers as Thailand made rapid progress in technological development. Because of a serious commitment and success in both education and research, MUT was promoted in a short time to advance to full university status under the new name Mahanakorn University of Technology .It is the first and still the only university in the country that operates its own low-orbit microsatellite . Wikipedia.


Time filter

Source Type

Punchalard R.,Mahanakorn University of Technology
Signal Processing | Year: 2012

In this paper, theoretical analysis for deriving the estimation of mean square error (MSE) at steady-state of an adaptive IIR notch filter using unbiased modified plain gradient (UMPG) algorithm is presented in closed form. Moreover, the stability bound of the algorithm is also derived. To confirm the analytical results, the computer simulations are conducted to corroborate the effectiveness of the UMPG algorithm. Furthermore, the performances of the algorithm are also compared with the modified plain gradient (MPG) algorithm, unbiased plain gradient (UPG) algorithm and simplified lattice algorithm (SLA). © 2012 Elsevier B.V. All rights reserved.


Wongcharee K.,Mahanakorn University of Technology | Eiamsa-ard S.,Mahanakorn University of Technology
International Communications in Heat and Mass Transfer | Year: 2012

Heat transfer enhancement by using CuO/water nanofluid in corrugated tube equipped with twisted tape is presented. The investigated ranges are (1) three different CuO concentrations: 0.3, 0.5 and 0.7% by volume (2) three different twist ratios of twisted tape: y/w = 2.7, 3.6 and 5.3 (3) two different arrangements of twisted direction of twisted tape relative to spiral direction of corrugated tube: parallel and counter arrangements, and (4) Reynolds number from 6200 to 24000. The results achieved from the use of the nanofluid and twisted tape, are compared with those obtained from the uses of nanofluid alone and twisted tape alone. The experimental results reveal that at similar operating conditions, heat transfer rate, friction factor as well as thermal performance factor associated with the simultaneous application of CuO/water nanofluid and twisted tape are higher than those associated with the individual techniques. Evidently, heat transfer rate increases with increasing CuO/water nanofluid concentration and decreasing twist ratio. In addition, the twisted tape coupled with corrugated tube in counter pattern offer higher heat transfer performances than the ones in parallel pattern. Over the range studied, the maximum thermal performance factor 1.57 is found with the use of CuO/water nanofluid at concentration of 0.7% by volume in corrugated tube together with twisted tape at twist ratio (y/w) of 2.7 (in counter arrangement), for Reynolds number of 6200 where heat transfer rate and friction factor increase to 2.67 times and 5.76 times of those in the plain corrugated tube. © 2011 Elsevier Ltd.


Wattanasakulpong N.,Mahanakorn University of Technology | Ungbhakorn V.,Chulalongkorn University
Computational Materials Science | Year: 2013

The objective of the present paper is to investigate the bending, buckling and vibration behaviors of carbon nanotube-reinforced composite (CNTRC) beams. The beams resting on the Pasternak elastic foundation, including a shear layer and Winkler spring, are considered. The single-walled carbon nanotubes (SWCNTs) are aligned and distributed in polymeric matrix with different patterns of reinforcement. The material properties of the CNTRC beams are estimated by using the rule of mixture. Various shear deformation theories are employed to deal with the problems. The mathematical models provided in this paper are numerically validated by comparison with some available results. New results of bending, buckling and vibration analyses of CNTRC beams based on several higher-order shear deformation theories are presented and discussed in details. Several aspects of beam types, spring constant factors, carbon nanotube volume fraction, etc., are taken into investigation. © 2013 Elsevier B.V. All rights reserved.


Eiamsa-Ard S.,Mahanakorn University of Technology | Promvonge P.,King Mongkut's University of Technology Thonburi
Applied Thermal Engineering | Year: 2010

The article presents an investigation of the effect of twisted tape with serrated-edge insert on heat transfer and pressure loss behaviors in a constant heat-fluxed tube. In the experiments, the serrated twisted tape (STT) was inserted into the entire test tube with a constant twist ratio in order to generate a continuous swirling airflow. Two geometry parameters of the STT to be considered in the present work are the serration width ratio and the serration depth ratio. The measurements have been conducted for the airflow rate based on Reynolds numbers in the turbulent regime from 4000 to 20,000. The experimental results of the STT inserted tube are compared with those of the plain tube fitted with typical twisted tape (TT). The results show that the heat transfer rate in terms of Nusselt number, Nu increases with the rise in the depth ratio but decreases with raising the width ratio. The heat transfer rate is up to 72.2% and 27% relative to the plain tube and the TT inserted tube, respectively. The use of the STT leads to higher heat transfer rate and friction factor than that of the TT for all cases. The thermal performance factor of the STT tube under constant pumping power is evaluated and found to be above unity indicating that using the STT tube is advantageous over the TT tube or the plain tube. In addition, the empirical correlations developed by relating the serration width ratio, serration depth ratio and Reynolds number are determined. © 2010 Elsevier Ltd. All rights reserved.


Eiamsa-ard S.,Mahanakorn University of Technology
International Communications in Heat and Mass Transfer | Year: 2010

The energy/temperature separation phenomenon and cooling efficiency characteristics in a counter-flow Ranque-Hilsch vortex tube (RHVT) are experimentally studied. The ascertainment focuses on the effects of the multiple inlet snail entries (N=1 to 4 nozzles), cold orifice diameter ratios (d/D=0.3 to 0.7) and inlet pressures (Pi=2.0 and 3.0bar). The experiments using the conventional tangential nozzles (N=4), are also performed for comparison. The experimental results reveal that the RHVT with the snail entry provides greater cold air temperature reduction and cooling efficiency than those offered by the RHVT with the conventional tangential inlet nozzle under the same cold mass fraction and supply inlet pressure. The increase in the nozzle number and the supply pressure leads to the rise of the swirl/vortex intensity and thus the energy separation in the tube. © 2010 Elsevier Ltd.


Eiamsa-ard S.,Mahanakorn University of Technology
International Communications in Heat and Mass Transfer | Year: 2010

This research has been performed to study the influences of multiple twisted tape vortex generators (MT-VG) on the heat transfer and fluid friction characteristics in a rectangular channel. The experiments conducted using the twisted tapes with three different twist ratios (y/w=2.5, 3.0 and 3.5) for generating different swirl and turbulent intensities in the channel. The twisted tapes are assembled to obtained the MT-VG with three different free-spacing ratios, s/w=1.66 (5 tapes), s/w=1.25 (7 tapes) and s/w=1.0 (9 tapes). The results for the Reynolds number ranged from 2700 to 9000 at constant Prandtl number, Pr= 0.7, using air as the test fluid, are examined. In the studied range, the presence of channel with MT-VG leads to increase in heat transfer rate over the use of smooth channel around 10.3 to 169.5%. The channel with the smaller twist ratio (y/w) and free-spacing ratio (s/w) provides higher heat transfer rate and pressure loss than those with the larger of twist ratio and free-spacing ratio under similar operation conditions. In addition, correlations of Nusselt number (Nu) and friction factor (f) have been developed and the thermal enhancement index at constant pumping power is also determined. © 2010 Elsevier Ltd.


Eiamsa-ard S.,Mahanakorn University of Technology | Promvonge P.,King Mongkut's University of Technology Thonburi
International Journal of Heat and Mass Transfer | Year: 2010

The article presents an experimental study of turbulent heat transfer and flow friction characteristics in a circular tube equipped with two types of twisted tapes: (1) typical twisted tapes and (2) alternate clockwise and counterclockwise twisted tapes (C-CC twisted tapes). Nine different C-CC twisted tapes are tested in the current work; they included the tapes with three twist ratios, y/w = 3.0, 4.0 and 5.0, each with three twist angles, θ = 30o, 60o and 90o. The experiments have been performed over a Reynolds number range of 3000-27,000 under uniform heat flux conditions, using water as working fluid. The obtained results reveal that the C-CC twisted-tapes provide higher heat transfer rate, friction factor and heat transfer enhancement index than the typical twisted-tapes at similar operating conditions. The results also show that the heat transfer rate of the C-CC tapes increases with the decrease of twist ratio and the increase of twist angle values. Depending on Reynolds number, twist ratio and twist angle values, the mean Nusselt numbers in the tube fitted with the C-CC twisted tapes are higher than those with the typical ones and the plain tube around 12.8-41.9% and 27.3-90.5%, respectively. The maximum heat transfer enhancement indexes of the C-CC twisted tapes with θ = 90o for y/w = 3.0, 4.0 and 5.0, are 1.4, 1.34 and 1.3, respectively. In addition, correlations of the Nusselt number and the friction factor for using the C-CC twisted tapes are also determined. Both predicted Nusselt number and friction factor are within ±15% and ±15% deviation compared to the experimental data. © 2009 Elsevier Ltd. All rights reserved.


Punchalard R.,Mahanakorn University of Technology
Signal Processing | Year: 2014

An arctangent (AT) based adaptive algorithm for a first-order complex adaptive IIR notch filter (CANF) is proposed in this paper. The objective of this work is to overcome some drawbacks including slow convergence speed and high sensitivity to impulsive noise of the previous gradient and nongradient based adaptive algorithms. The proposed AT algorithm employs the ratio of output to regressor signal as an error criterion where the arctangent value of such a ratio is employed to adjust the filter parameter. It is found that the proposed algorithm provides not only high speed convergence but also high impulsive noise robustness. Moreover, very low bias of the frequency estimate is also obtained. In addition, difference equation for the convergence in the mean and coarse stability bound in mean sense are derived. Computer simulations are conducted to show the performance of the proposed AT algorithm. © 2013 Elsevier B.V. All rights reserved.


Wongcharee K.,Mahanakorn University of Technology | Eiamsa-ard S.,Mahanakorn University of Technology
International Communications in Heat and Mass Transfer | Year: 2011

Heat transfer, friction and thermal performance characteristics of CuO/water nanofluid have been experimentally investigated. The nanofluid was employed in a circular tube equipped with modified twisted tape with alternate axis (TA). The concentration of nanofluid was varied from 0.3 to 0.7% by volume while the twisted ratio (y/W) of TA was kept constant at 3. The experiments were performed in laminar regime (Reynolds number spanned 830 ≤ Re ≤ 1990). The uses of nanofluid together with typical twisted tape (TT), TA alone and TT alone were also examined. To evaluate heat transfer enhancement and the increase of friction factor, the Nusselt number and friction factor of the base fluid in the plain tube were employed as reference data. The obtained results reveal that Nusselt number increases with increasing Reynolds number and nanofluid concentration. By the individual uses of TA and TT, Nusselt numbers increase up to 12.8 and 7.2 times of the plain tube, respectively. The simultaneous use of nanofluid and TA improves Nusselt number up to 13.8 times of the plain tube. Over the range investigated, the maximum thermal performance factor of 5.53 is found with the simultaneous employment of the CuO/water nanofluid at 0.7% volume and the TA at Reynolds number of 1990. In addition, the empirical correlations for heat transfer coefficient, friction factor and thermal performance factor are also developed and reported. © 2011 Elsevier Ltd.


Wongcharee K.,Mahanakorn University of Technology | Eiamsa-ard S.,Mahanakorn University of Technology
International Communications in Heat and Mass Transfer | Year: 2011

The thermohydraulic characteristics of the circular tubes equipped with alternate clockwise and counter-clockwise twisted-tapes (TA) for the Reynolds number ranging from 830 to 1990, are reported. In the experiments, the twisted tapes with three different twist ratios (y/W = 3, 4 and 5) were inserted individually into the uniform wall heat flux tubes where water was utilized as the working fluid. The plain tube and the tube inserted with twisted tape (TT) were also tested, for comparison. The obtained results reveal that, Nusselt number, friction factor and thermal performance factor associated by TA are higher than those associated by TT. Among the tapes examined, the one with the smallest twist ratio of y/W = 3 is found to be the most efficient for heat transfer enhancement. For the range studied, the applications of both TT and TA for heat transfer enhancement are found to be promising since the thermal performance factors determined under the same pumping power are all above unity. In addition, the empirical correlations for Nusselt number, friction factor and thermal performance factor have also been developed. The consequential results obtained from the correlations are found to be in good agreement with the experimental results within ± 8% variation for Nusselt number (Nu), ± 8% for thermal performance factor (η) and ± 5% for friction factor (f). © 2010 Elsevier Ltd.

Loading Mahanakorn University of Technology collaborators
Loading Mahanakorn University of Technology collaborators