Performance analysis of PCM curtain for thermal comfort

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shubham Srivastava ◽  
Abhishek Srivastava ◽  
Sanya Jain ◽  
Nandan Kumar ◽  
Chandra Shekhar Malvi
Keyword(s):  
Thermal Comfort ◽  
Design Methodology ◽  
Phase Change Materials ◽  
Heat Exposure ◽  
Mean Square ◽  
Constant Heat ◽  
Content Type ◽  
One Dimensional ◽  
Simulation Results ◽  
Modelling Assumptions

Purpose This study aims to analyse the variations of thermal comfort inside a building space by using different curtains. Design/methodology/approach Phase change materials (PCMs) such as wax, sand and mixture of sand and wax were used with cotton curtain to compare the results of PCM curtains with the performance of normal cotton curtain against constant heat exposure. Heat exposure was provided with halogen to simulate the solar radiation. Further simulation was performed on ANSYS and experimental results were compared with the simulation results. In addition to this, the results were analysed for optimized performance by calculation root mean square error. Findings It was found that PCM used curtains that have better performance than normal curtain. Furthermore, sand curtain was proved as the best curtain and mixture of sand and wax curtain could replace the sand curtain where there is limitation of weight; also, there was less error between experimental and simulation was reported for sand curtain as compare to other curtains. Research limitations/implications Layers of different PCMs were used before cotton curtain and in modelling assumptions such as one-dimensional heat transfer, uniform thermal conductivity. Originality/value To the best of the authors’ knowledge, there is no such study that was performed earlier.

Evaluation of compression-recovery and thermal characteristics of multilayer bedding textiles

2020 ◽  
Vol 32 (5) ◽  
pp. 631-643
Author(s):  
Sedat Özer ◽  
Yaşar Erayman Yüksel ◽  
Yasemin Korkmaz
Keyword(s):  
Thermal Conductivity ◽  
Sleep Quality ◽  
Thermal Comfort ◽  
Sleep Duration ◽  
Human Body ◽  
Design Methodology ◽  
Thermal Characteristics ◽  
Air Permeability ◽  
Content Type ◽  
Thermal Comfort Properties

PurposeDesign of bedding textiles that contact the human body affects the sleep quality. Bedding textiles contribute to comfort sense during the sleep duration, in addition to ambient and bed microclimate. The purpose of this study is to evaluate the effects of different layer properties on the compression recovery and thermal characteristics of multilayer bedding textiles.Design/methodology/approachIn this study, woven and knitted multilayer bedding textiles were manufactured from fabric, fiber, sponge and interlining, respectively. Different sponge thickness, fiber and interlining weight were used in the layers of samples. Later, the pilling resistance, compression and recovery, air permeability and thermal conductivity of multilayer bedding textiles were investigated.FindingsThe results indicated that samples with the higher layer weight and thickness provide better compression recovery and lower air permeability properties. It was also found that knitted surfaces show the higher air permeability than the woven surfaces depending on the fabric porosity. Layer properties have insignificant effect on the thermal conductivity values.Originality/valueWhile researchers mostly focus on thermal comfort properties of garments, there are limited studies about comfort properties of bedding textiles in the literature. Furthermore, compression recovery properties of bedding textiles have also a great importance in terms of comfort. Originality of this study is that these properties were analyzed together.

Simple correlations for calculating NHTPB enthalpy of formation through molecular structures

2019 ◽  
Vol 15 (1) ◽  
pp. 258-264 ◽  
Author(s):  
Hamid Reza Ghaieni ◽  
Saeed Tavangar ◽  
Mohammad Moein Ebrahimzadeh Qhomi
Keyword(s):  
Enthalpy Of Formation ◽  
Design Methodology ◽  
Predictive Power ◽  
Cross Validation ◽  
Molecular Structures ◽  
Mean Square ◽  
Mean Square Deviation ◽  
Simple Correlation ◽  
Content Type ◽  
Regression Methods

Purpose The purpose of this paper is to present simple correlation for calculating nitrated hydroxyl-terminated polybutadiene (NHTPB) enthalpy of formation. Design/methodology/approach It uses multiple linear regression methods. Findings The proposed correlation has determination coefficient 0.96. The correlation has root mean square deviation and the average absolute deviations values 53.4 and 46.1 respectively. Originality/value The predictive power of correlation is checked by cross-validation method (R2=0.96, Q L O O 2 = 0.96 ).

Design and optimization of heating, cooling and lightening systems for a residential villa at Saman city, Iran

2019 ◽  
Vol 17 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Javad Riahi Zaniani ◽  
Shahab Taghipour Ghahfarokhi ◽  
Mehdi Jahangiri ◽  
Akbar Alidadi Shamsabadi
Keyword(s):  
Energy Consumption ◽  
Light Intensity ◽  
Design Methodology ◽  
Climatic Conditions ◽  
Content Type ◽  
Design And Optimization ◽  
Simulation Results ◽  
Annual Reduction ◽  
Reduction Of Energy Consumption ◽  
Heating Loads

Purpose This paper, using energy softwares, designed of Iran and optimized a residential villa in Saman city located in Chaharmahal and Bakhtiari Province. Design/methodology/approach Having used the ideas of Climate Consultant software, the basic designing was conducted by Design Builder Software, and the cooling and heating loads and lighting tools and equipment were calculated. Then, the amount of consuming of heating, cooling and lighting load of the building was optimized through insulation of walls and ceiling, using green roof, double glazing UPVC windows, light intensity sensor and variable refrigerant flow (VRF) system. Findings Simulation results for the stated scenarios showed an annual reduction in energy consumption of 21.1, 7.9, 26.41, 27.3 and 72.3 per cent, respectively. Also, by combining all the five scenarios, an optimal state was achieved which, from the results, brought about an annual reduction of 86.9 per cent in the energy consumption. Originality/value The authors hope that the results of the current paper could be helpful for designers and engineers in reduction of energy consumption for designing a building in similar climatic conditions.

Design and vibration analysis of a self-adaptive piston in a novel nanoimprint system

2017 ◽  
Vol 69 (4) ◽  
pp. 591-597
Author(s):  
Chaoran Liu ◽  
Yufeng Su ◽  
Jinzhao Yue ◽  
Junjie Wang ◽  
Weiwei Xia ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Vibration Analysis ◽  
Design Methodology ◽  
The Self ◽  
Ball Screw ◽  
Piston Rings ◽  
Content Type ◽  
Simulation Results ◽  
The One ◽  
Self Adaptive

Purpose A self-adaptive piston is designed for the compressional gas cushion press nanoimprint lithography system. It avoids the lube pollution and high wear of traditional piston. Design/methodology/approach The self-adaptive piston device consists of symmetrical piston bodies, piston rings and other parts. The two piston bodies are linked by a ball-screw. The locking nut adjusts the distance between two piston bodies to avoid the piston rings from being stuck. The piston rings are placed between two piston bodies. Findings The simulation results based on COMSOL indicate that cylinder vibration caused by self-adaptive piston is 15.9 times smaller than the one caused by a traditional piston. Originality/value The self-adaptive piston is superior to the traditional piston in decreasing cylinder vibration.

An improved circuit for modulator based on nanostructured memristor

Circuit World ◽  
2016 ◽  
Vol 42 (4) ◽  
pp. 178-182 ◽  
Author(s):  
Shao-Fu Wang ◽  
D.Z. Xu
Keyword(s):  
Amplitude Modulation ◽  
Design Methodology ◽  
Content Type ◽  
Amplitude Modulator ◽  
Simulation Results

Purpose This paper aims to propose the modeling of nanostructured memristor, and the circuit of amplitude modulator was designed and analyzed with memristor. The simulation results show that the nanostructured memristor can be utilized to implement the desired amplitude modulated signal. Design/methodology/approach The modeling of nanostructured memristor is proposed in this paper, and the circuit of amplitude modulator was designed and analyzed with memristor, amplifiers and BPF device. For measuring the modulated signal, the emulator circuit of memristor is designed. The simulation results show that the nanostructured memristor can be utilized to implement the desired amplitude modulated signal. Findings The innovations of this work are as follows: the AM modulator circuit using memristor has been proposed, analyzed and simulated. The emulator of memristor is given. Originality/value The innovations of this work are as follows: the AM modulator circuit using memristor has been proposed, analyzed and simulated. The emulator of memristor is given, and the results of this work demonstrate that the nonlinearity of the memristor can be used to generate the desired amplitude modulation free of harmonic sidebands, because of distortion of the modulating signal.

Surfaces with pores: hydrodynamic lubrication

2017 ◽  
Vol 69 (4) ◽  
pp. 471-483 ◽  
Author(s):  
Leonid Burstein
Keyword(s):  
Design Methodology ◽  
Hydrodynamic Lubrication ◽  
Dimensional Model ◽  
Hydrodynamic Behavior ◽  
Content Type ◽  
One Dimensional ◽  
Lubricating Film ◽  
Cell Dimensions ◽  
Practical Implications ◽  
Pore Cell

Purpose This paper aims to assess the hydrodynamic lubrication of two opposing surfaces with identical pores having a semicircular profile. The surfaces are treated with more than one pore that allows clarification of whether there exists interaction between the pores. Design/methodology/approach A transient, spatial, one-dimensional model of surfaces with regular pores was developed and applied in the context of fluid lubrication. MATLAB software has been used. Findings Calculations show that a lubricating film between two surfaces with pores provides better hydrodynamic conditions in comparison to that on one surface with pores. It was also shown that the pores of one surface act as separate objects and can take into account only the interaction between the pores of the opposite surfaces. In addition, it was found that there are optimum values of the pore radii, gap and pore cell dimensions at which the bearing capacity of the film is maximal. Practical implications The computer program used for the pore parameter calculations provided the optimal lubrication. Originality/value This is the first study of the lubricating film hydrodynamic behavior of two opposite surfaces with pores having a semicircular profile.

Evaluation of occupant's adaptive thermal comfort behaviour in naturally ventilated courtyard houses

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Peiman Pilechiha ◽  
Alireza Norouziasas ◽  
Hoorieh Ghorbani Naeini ◽  
Kasmir Jolma
Keyword(s):  
Thermal Comfort ◽  
Design Methodology ◽  
Construction Materials ◽  
Parametric Models ◽  
Content Type ◽  
Seasonal Movement ◽  
Indoor Thermal Comfort ◽  
Adaptive Thermal Comfort ◽  
Vernacular Buildings ◽  
Hourly Basis

PurposeIn vernacular buildings, many climatic and passive solutions have been used to create indoor thermal comfort. Seasonal occupant movement is an example of a traditional response to increasing thermal comfort. This article investigates the influence of these user behaviours on thermal comfort in courtyard houses.Design/methodology/approachParametric models of three different scenarios of courtyard houses are simulated. The courtyard houses are located in Shiraz, Iran, and share the same orientation and construction materials. To enhance the accuracy of the study, the indoor adaptive thermal comfort (ATC) analysis is performed with three different window-to-wall ratios (WWR) of 25, 50 and 75%. The ACT analysis is performed on an hourly basis for summer and winter scenarios.FindingsThe results demonstrate that the indoor ATC is 8.3% higher in winter than in the summer in the seasonal zones. During the summer, the amount of ATC is relatively sustained in all zones. Unlike common beliefs, seasonal movement can enhance the ATC, especially during winter, specifically in the northern part of the courtyard. In northern zones, the seasonal movement of occupants improves the indoor ATC from 10.1 to 23.7%, and in southern zones, the improvement is from 2.2 to 4.8%.Originality/valueThis research presents a new numerical investigation into occupants' seasonal movements in courtyard houses during summer and winter. It provides a precise pattern to show how much this seasonal movement can affect the habitant's ATC.

Induction motors broken rotor bars detection using RPVM and neural network

2019 ◽  
Vol 38 (2) ◽  
pp. 596-615 ◽  
Author(s):  
Saddam Bensaoucha ◽  
Sid Ahmed Bessedik ◽  
Aissa Ameur ◽  
Ali Teta
Keyword(s):  
Design Methodology ◽  
Induction Motors ◽  
Content Type ◽  
Broken Rotor Bars ◽  
Squirrel Cage ◽  
Detection And Identification ◽  
Squirrel Cage Induction Motor ◽  
Simulation Results ◽  
Cage Induction Motor ◽  
Diagnosis Technique

Purpose The purpose of this study aims to focus on the detection and identification of the broken rotor bars (BRBs) of a squirrel cage induction motor (SCIM). The presented diagnosis technique is based on artificial neural networks (NNs) that use as inputs the results of the spectral analysis using the fast Fourier transform (FFT) of the reduced Park’s vector modulus (RPVM), along with the load values in which the motor operates. Design/methodology/approach First, this paper presents a comparative study between FFT applied on Hilbert modulus, Park’s vector modulus and RPVM to extract feature frequencies of BRB faults. Moreover, the extracted features of FFT applied to RPVM and the load values were selected as NNs’ inputs for the detection of the number of BRBs. Findings The obtained simulation results using MATLAB (Matrix Laboratory) environment show the effectiveness and accuracy of the proposed NNs based approach. Originality/value The current paper presents a novel diagnostic method for BRBs’ fault detection in SCIM, based on the combination between the signal processing analysis (FFT of RPVM) and artificial intelligence (NNs).

Predicting formulae for effective length of counterpoise wires buried in ionized, dispersive and inhomogeneous soils

2020 ◽  
Vol 39 (6) ◽  
pp. 1375-1391
Author(s):  
Seyyed Sajjad Sajjadi ◽  
Saeed Reza Ostadzadeh
Keyword(s):  
Sensitivity Analysis ◽  
Transmission Line ◽  
Design Methodology ◽  
Effective Length ◽  
Transmission Line Model ◽  
Line Model ◽  
Content Type ◽  
Dispersion Effects ◽  
Simulation Results

Purpose The purpose of this paper is to investigate the ionization and dispersion effects in combination with the inhomogeneity of soil simultaneously on the effective lengths of counterpoise wires. Design/methodology/approach Improved multi-conductor transmission line model is used for computing effective length of counterpoise wires considering all aspects of soils. Findings The simulation results show that the ionization and dispersion effects simultaneously results in placing the effective length between situations where only one effect is considered. Also, predicting formulae for effective length of counterpoise wires considering all effects are proposed. Originality/value A sensitivity analysis on the effective lengths of counterpoise wires considering all aspects of soils is carried out.

Temperature distribution simulations during electron beam freeform fabrication process based on the fully threaded tree

2019 ◽  
Vol 25 (6) ◽  
pp. 989-997
Author(s):  
Yajun Yin ◽  
Wei Duan ◽  
Kai Wu ◽  
Yangdong Li ◽  
Jianxin Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Temperature Distribution ◽  
Design Methodology ◽  
Content Type ◽  
Freeform Fabrication ◽  
Simulation Based ◽  
Simulation Results

Purpose The purpose of this study is to simulate the temperature distribution during an electron beam freeform fabrication (EBF3) process based on a fully threaded tree (FTT) technique in various scales and to analyze the temperature variation with time in different regions of the part. Design/methodology/approach This study presented a revised model for the temperature simulation in the EBF3 process. The FTT technique was then adopted as an adaptive grid strategy in the simulation. Based on the simulation results, an analysis regarding the temperature distribution of a circular deposit and substrate was performed. Findings The FTT technique was successfully adopted in the simulation of the temperature field during the EBF3 process. The temperature bands and oscillating temperature curves appeared in the deposit and substrate. Originality/value The FTT technique was introduced into the numerical simulation of an additive manufacturing process. The efficiency of the process was improved, and the FTT technique was convenient for the 3D simulations and multi-pass deposits.

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