Brenton S. Taft^a,*, Kevin W. Irick^b

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-7, 2019, DOI:10.5098/hmt.12.24

Abstract On September 7th, 2017 the U.S. Air Force Research Laboratory launched the second Advanced Structurally Embedded Thermal Spreader (ASETSII) flight experiment to space on Orbital Test Vehicle 5. The ASETS-II experiment is made of three low-mass, low-cost oscillating heat pipes (OHPs) and an electronics/experiment control box. The three primary science objectives of the experiment are to measure the initial on-orbit thermal performance, to measure long duration thermal performance, and to assess any lifetime degradation. The three OHPs on ASETS-II are of varying configuration (center heating with single- and double-sided cooling) and working fluids (butane and R-134a) in order to isolate… More >

Changming Ling^a,b,*, Yin Zhong^a,b

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-6, 2020, DOI:10.5098/hmt.14.25

Abstract Effects of serrated pulsating airflow on liquid film evaporation in a falling film channel was numerically studied based on a two-dimensional model. The mechanism of pulsating airflow evaporation was studied as the pulsating airflow swept across the vertical liquid film surface at the stagnant temperature. Effects of amplitude, frequency, and velocity of the serrated pulsating airflow at certain evaporation time on evaporation were analyzed. Compared with the uniform airflow, the highest relative evaporation of liquid film on vertical pipe inner surface was increased by about 0.3 %. When the airflow was pulsating, the cycle of vapor mass flow rate was… More >

Wakana Hiratsuka^a , Takashi Fukue^b,*, Hidemi Shirakawa^c, Katsuyuki Nakayama^d, Yasushi Koito^e

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-8, 2020, DOI:10.5098/hmt.15.16

Abstract This paper describes a possibility of heat transfer enhancement in a mm-scale flow channel by using a combination of some projections and pulsating flow. The objective of this research is to develop a novel heat exchanger for miniaturized productions such as high-density packaging electronic equipment by applying pulsating flow to enhance heat transfer while inhibiting an increase of pressure drop. In order to evaluate the possibility of applying pulsating flow to miniature water channels, a three-dimensional flow and heat transfer analysis was performed. Heat transfer performance of a combination of pulsating water flow and a projection was investigated. The mechanism… More >

Roshan Devidas Bhagat^a,*, Samir J. Deshmukh^b

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-16, 2021, DOI:10.5098/hmt.16.23

Abstract Numerical analysis of passive two phase fluid flow in a 3D Closed Loop Pulsating Heat Pipe (CLPHP) with turns in evaporator and condenser section is carried out. Water is used as working fluid. The volume of fluid model (VOF) is used to simulate passive two-phase fluid flow in a Closed Loop Pulsating Heat Pipe. Filling ratio (FR) of is kept in the range of 60 to 70%. The evaporator temperature is set in the range of 353 K. The condenser temperature is set in the range of 298 K. The contours of volume fraction water, wall temperature and contours of… More >

Felix Schily^a,∗, Wolfgang Polifke^a

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-15, 2021, DOI:10.5098/hmt.17.16

Abstract A simple open-loop pulsating heat pipe model is proposed, which allows to analytically determine the start-up behavior by a linear stability analysis. Two distinct types of instability can occur in such a pulsating heat pipe: oscillatory and non-oscillatory. This paper demonstrates that for bubbles consisting of non-condensible gas, large temperature gradients along the wall are required to achieve start-up, whereas start-up is fairly easy to achieve when there is only a single working medium that forms bubbles from its vapor. The study also finds that surface tension as such only influences start-up indirectly, while contact angle hysteresis dampens out any… More >

Shintaro Hayakawa^a , Takashi Fukue^a,*,† , Yasuhiro Sugimoto^a , Wakana Hiratsuka^b , Hidemi Shirakawa^c , Yasushi Koito^d

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-9, 2022, DOI:10.5098/hmt.18.29

Abstract This paper describes the effects of a combination of rib and pulsating flow on heat transfer enhancement in an mm-scale model that simulates the narrow flow passages in cooling devices of downsized electronic equipment. This research aims to develop a novel water cooling device that increases heat transfer performance while inhibiting pumping power. Our recent study has reported that a combination of pulsating flow and rib could enhance heat transfer performance relative to the simple duct. In the present study, to verify the optimal rib height for improving heat transfer by pulsating flow, we evaluated the relationship between heat transfer… More >

Mesfer Al Duhayyim^1,*, Jaber S. Alzahrani², Hanan Abdullah Mengash³, Mrim M. Alnfiai⁴, Radwa Marzouk³, Gouse Pasha Mohammed⁵, Mohammed Rizwanullah⁵, Amgad Atta Abdelmageed⁵

Computer Systems Science and Engineering, Vol.46, No.2, pp. 1471-1485, 2023, DOI:10.32604/csse.2023.034137

Abstract The Internet of Things (IoT) environment plays a crucial role in the design of smart environments. Security and privacy are the major challenging problems that exist in the design of IoT-enabled real-time environments. Security susceptibilities in IoT-based systems pose security threats which affect smart environment applications. Intrusion detection systems (IDS) can be used for IoT environments to mitigate IoT-related security attacks which use few security vulnerabilities. This paper introduces a modified garden balsan optimization-based machine learning model for intrusion detection (MGBO-MLID) in the IoT cloud environment. The presented MGBO-MLID technique focuses on the identification and classification of intrusions in the… More >

Rawia Abdulla Mohammed^1,*, Maisa’a Abid Ali Khodher¹, Ashwak Alabaichi²

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 2137-2153, 2023, DOI:10.32604/cmc.2023.036861

Abstract Encryption algorithms are one of the methods to protect data during its transmission through an unsafe transmission medium. But encryption methods need a lot of time during encryption and decryption, so it is necessary to find encryption algorithms that consume little time while preserving the security of the data. In this paper, more than one algorithm was combined to obtain high security with a short implementation time. A chaotic system, DNA computing, and Salsa20 were combined. A proposed 5D chaos system was used to generate more robust keys in a Salsa algorithm and DNA computing. Also, the confusion is performed… More >

Dan Zhao^1,*, Qiong Wu¹, Minyao Gan², Ke Li¹, Wenhong Ma¹, Qun Wu¹, Liqiang Dong¹, Shaogang Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.3, pp. 2041-2055, 2023, DOI:10.32604/cmes.2022.021026

Abstract To reduce the vibration and sound radiation of underwater cylindrical shells, a skin composed of micro floating raft arrays and a compliant wall is proposed in this paper. A vibroacoustic coupling model of a finite cylindrical shell covered with this skin for the case of turbulence excitation is established based on the shell theories of Donnell. The model is solved with the modal superposition method to investigate the effects of the structural parameters of micro floating raft elements on the performance of reducing vibration and sound radiation of the cylindrical shell of this skin. The results indicate that increasing the… More >

Reeya Agrawal^1,*, Anjan Kumar¹, Salman A. AlQahtani², Mashael Maashi³, Osamah Ibrahim Khalaf⁴, Theyazn H. H. Aldhyani⁵

CMC-Computers, Materials & Continua, Vol.73, No.2, pp. 2313-2331, 2022, DOI:10.32604/cmc.2022.029019

Abstract Most modern microprocessors have one or two levels of on-chip caches to make things run faster, but this is not always the case. Most of the time, these caches are made of static random access memory cells. They take up a lot of space on the chip and use a lot of electricity. A lot of the time, low power is more important than several aspects. This is true for phones and tablets. Cache memory design for single bit architecture consists of six transistors static random access memory cell, a circuit of write driver, and sense amplifiers (such as voltage… More >