scholarly journals Influence of Multilayer Interlocked Fabrics Structure on their Thermal Performance

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ferran Parés ◽  
Heura Ventura ◽  
F. Xavier Capdevila ◽  
Mònica Ardanuy
Keyword(s):  
Thermal Performance ◽  
Radiative Heat ◽  
Desirability Function ◽  
Thermal Response ◽  
Woven Fabrics ◽  
Yarn Count ◽  
Fabric Structures ◽  
Protective Performance ◽  
Air Cells ◽  
Plot Design

Abstract This paper examines the influence of weaving variables such as yarn count, number of layers, warp and weft ratio, materials of the top layer, weft density and interlocking cell shape, and size on the thermal performance of multilayer interlocked woven fabrics. A split-plot design was used to construct a total of 64 fabric structures, which were assessed for thermal performance in terms of resistance to convective, conductive, and radiative heat. It was found that, for equal weft density and yarn number, protective performance improved with the number of fabric layers and with the presence of air cells between these layers, especially if air was not trapped within and could rather pass freely between the cells. An optimal combination of factors for the thermal response to the three types of heat was established via a Derringer–a much needed desirability function. The results of this paper are useful for identifying the interaction between configuration parameters and thermal performance, and hence for the design of improved heat protective clothing.

Effect of Corrugated Cover Directional Transmittance on the Thermal Performance of a Solar Collector

1981 ◽  
Vol 103 (2) ◽  
pp. 144-152
Author(s):  
T. F. Smith ◽  
S. Chaidar
Keyword(s):  
Solar Energy ◽  
Periodic Function ◽  
Thermal Performance ◽  
Solar Collector ◽  
Radiative Heat ◽  
Structural Strength ◽  
Heat Losses ◽  
Light Weight ◽  
Fiberglass Composite ◽  
Reduced Costs

The benefits of light weight, structural strength, and reduced costs without significant reduction of transmission of solar energy of a corrugated fiberglass composite cover promise wide utilization of this cover in solar collectors to suppress convective and radiative heat losses from the absorber panel. In order to evaluate the thermal performance of a collector with a corrugated cover, the directional transmittance of the cover must be available. A study was undertaken to develop a model for the directional transmittance of a corrugated cover as represented by a sinusoidal periodic function. As an application of this model, hourly and daily thermal efficiencies of a solar collector with a corrugated cover are presented.

scholarly journals Method of Predicting the Crimp of Jacquard-Woven Fabrics

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5157
Author(s):  
Eglė Kumpikaitė ◽  
Eglė Lapelytė ◽  
Stasė Petraitienė
Keyword(s):  
Woven Fabrics ◽  
Fabric Structures ◽  
Weaving Loom ◽  
Structural Solutions ◽  
Setting Parameters ◽  
Jacquard Weaving

The aim of this study was to investigate the distribution of crimp in new jacquard fabric structures (in which one-layer and two-layer weaves are combined) in the fabric width and to create a method of crimp prediction. It was established that crimp was around 18.80% and changed within the limits of errors, i.e., a range of only ~4%, in the fabric width. It can therefore be said that the warp crimp was constant in the fabric width. Because the warp crimp of jacquard fabric changed insignificantly (within the limits of errors), it can be stated that the fabric-setting parameters and structural solutions were chosen and matched correctly, and such fabric can be woven on any jacquard weaving loom.

scholarly journals Limitations of the CAD-CAM System in the Process of Weaving

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Stana Kovačević ◽  
Snježana Brnada ◽  
Irena Šabarić ◽  
Franka Karin
Keyword(s):  
Woven Fabrics ◽  
Virtual Simulation ◽  
Woven Fabric ◽  
Virtual Image ◽  
Computer Screen ◽  
Cad Cam ◽  
Fabric Structures

AbstractThe weaving process is constantly evolving in terms of productivity, quality, and possibilities of fabrication of different fabric structures and shapes. This article covers some issues that have still not been resolved and represents distracting factors in the woven fabrics production. In the development of woven fabric using the CAD technology, it is inevitably a deviation of the virtual image on the computer screen from the woven sample. According to comprehensive industry analyses, the findings of many authors who contributed to the resolution of these problems can be concluded that these problems are still present in the development and production of striped, checkered, and jacquard woven fabrics. In this article, jacquard, multicolor woven fabrics were investigated, with deviations in pattern sizes and shades of color in warp and weft systems compared to virtual simulation on the computer, as well as the tendency of the weft distortion arising from the weaving process leading to the pattern deformation.

Optimization of bending and shear rigidities of woven fabrics using desirability function

2019 ◽  
Vol 111 (9) ◽  
pp. 1318-1323 ◽  
Author(s):  
Md Samsu Alam ◽  
Anindya Ghosh ◽  
Abhijit Majumdar
Keyword(s):  
Desirability Function ◽  
Woven Fabrics

An Experimental Study on the Thermal Performance Evaluation of SCW Ground Heat Exchanger

2017 ◽  
Vol 25 (01) ◽  
pp. 1750006 ◽  
Author(s):  
Keun Sun Chang ◽  
Min Jun Kim ◽  
Young Jae Kim
Keyword(s):  
Thermal Conductivity ◽  
Performance Evaluation ◽  
Heat Exchanger ◽  
Effective Thermal Conductivity ◽  
Thermal Performance ◽  
Thermal Response ◽  
High Heat ◽  
Injection Rate ◽  
Operating Parameters ◽  
Ground Heat Exchanger

In recent years, application of the standing column well (SCW) ground heat exchanger (GHX) has been noticeably increased as a heat transfer mechanism of ground source heat pump (GSHP) systems with its high heat capacity and efficiency. Determination of the ground thermal properties is an important task for sizing and estimating cost of the GHX. In this study, an in situ thermal response test (TRT) is applied to the thermal performance evaluation of SCW. Two SCWs with different design configurations are installed in sequence to evaluate their effects on the thermal performance of SCW using a single borehole. A line source method is used to derive the effective thermal conductivity and borehole thermal resistance. Effects of operating parameters are also investigated including bleed, heat injection rate, flow rate and filler height. Results show that the effective thermal conductivity of top drawn SCW (Type A) is 11.7% higher than that of bottom drawn SCW (Type B) and of operating parameters tested bleed is the most significant one for the improvement of the thermal performance (40.4% enhanced in thermal conductivity with 10.9% bleed).

Effect of weave structure on the slicing cut resistance of woven fabrics

2019 ◽  
Vol 90 (13-14) ◽  
pp. 1477-1494
Author(s):  
Magdi El Messiry ◽  
Shaimaa El-Tarfawy
Keyword(s):  
High Performance ◽  
Normal Load ◽  
Cutting Speed ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Weft Yarn ◽  
Fabric Structure ◽  
Yarn Count ◽  
Highly Correlated ◽  
Cutting Processes

Cutting processes using blades have found applications in many industries; for example, in garments, fiber–polymer composites, and high-performance fabric forming. In recent decades, the process of cutting the material using a robotic-controlled blade has raised concern about the value of the pressure and the cut force required for a certain type of woven fabric and the estimation of its value before the pressing and cutting process. A simple theoretical relation was established based on the fabric structure and yarn shear stress. The model formulation and experimental results to describe the basic theory of blade cutting fracture for woven fabric of different designs was derived. In this work, the experimental investigation of the effect of the fabric specifications, normal load, and the cutting speed on the cutting force was carried out, which indicates that the value of the specific cutting resistance of the fabric was found to be highly correlated with the fabric structure, warp and weft yarn count, Young’s modulus of the fabric, and fractional cover factors ratio ζ.

scholarly journals Effects of Absorber Emissivity on Thermal Performance of a Solar Cavity Receiver

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jiabin Fang ◽  
Nan Tu ◽  
Jinjia Wei
Keyword(s):  
Heat Loss ◽  
Thermal Performance ◽  
Thermal Efficiency ◽  
Radiative Heat ◽  
Slight Effect ◽  
Radiative Heat Loss ◽  
Total Heat Loss ◽  
Convective Heat Loss ◽  
Performance Curves ◽  
Variation Tendency

Solar cavity receiver is a key component to realize the light-heat conversion in tower-type solar power system. It usually has an aperture for concentrated sunlight coming in, and the heat loss is unavoidable because of this aperture. Generally, in order to improve the thermal efficiency, a layer of coating having high absorptivity for sunlight would be covered on the surface of the absorber tubes inside the cavity receiver. As a result, it is necessary to investigate the effects of the emissivity of absorber tubes on the thermal performance of the receiver. In the present work, the thermal performances of the receiver with different absorber emissivity were numerically simulated. The results showed that the thermal efficiency increases and the total heat loss decreases with increasing emissivity of absorber tubes. However, the thermal efficiency increases by only 1.6% when the emissivity of tubes varies from 0.2 to 0.8. Therefore, the change of absorber emissivity has slight effect on the thermal performance of the receiver. The reason for variation tendency of performance curves was also carefully analyzed. It was found that the temperature reduction of the cavity walls causes the decrease of the radiative heat loss and the convective heat loss.

scholarly journals Ultraviolet Protection by Fabric Engineering

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mukesh Kumar Singh ◽  
Annika Singh
Keyword(s):  
Areal Density ◽  
Woven Fabrics ◽  
Uv Protection ◽  
Comfort Level ◽  
Protection Factor ◽  
Ultraviolet Protection Factor ◽  
Wear Comfort ◽  
Ultraviolet Protection ◽  
Multifilament Yarns ◽  
Fabric Structures

Background. The increasing emission of greenhouse gases has evoked the human being to save the ozone layer and minimize the risk of ultraviolet radiation (UVR). Various fabric structures have been explored to achieve desired ultraviolet protection factor (UPF) in various situations. Objective. In this study, the effect of various filament configurations like twisted, flat, intermingled, and textured in multifilament yarns on fabric in different combinations is assessed in order to engineer a fabric of better ultraviolet protection factor (UPF). Methods. In order to engineer a fabric having optimum UV protection with sufficient comfort level in multifilament woven fabrics, four different yarn configurations, intermingled, textured, twisted, and flat, were used to develop twelve different fabric samples. The most UV absorbing and most demanding fibre polyethylene terephthalate (PET) was considered in different filament configuration. Results. The combinations of intermingled warp with flat, intermingled, and textured weft provided excellent UVR protection comparatively at about 22.5 mg/cm2 fabric areal density. The presence of twisted yarn reduced the UV protection due to enhanced openness in fabric structure. Conclusion. The appropriate combination of warp and weft threads of different configuration should be selected judiciously in order to extract maximum UV protection and wear comfort attributes in multifilament woven PET fabrics.

Advances in Fabric and Structural Analyses of Pressure Inflated Structures

2003 ◽  
Author(s):  
Claudia J. Quigley ◽  
Paul V. Cavallaro ◽  
Arthur R. Johnson ◽  
Ali M. Sadegh
Keyword(s):  
Strain Energy ◽  
Structural Response ◽  
Beam Theory ◽  
Woven Fabrics ◽  
Material Behavior ◽  
One Dimension ◽  
Energy Potential ◽  
Energy Principle ◽  
Effective Material Properties ◽  
Fabric Structures

Novel methods for analyzing the response of air inflated fabric structures are presented. The first method determines the global structural response of air inflated beam and arch structures. It employs a previously developed specialized finite element. The element was derived by minimizing the strain energy potential for a cylindrical membrane deforming about its pressurized state. Through the use of displacement approximations defining the motion of the beam’s cross section, analogous to classical beam theory, the energy principle is reduced to one dimension. However, the effect of the pressure is included in the formulation. Numerical results compare favorably to experimental data for air beams constructed from Vectran®. The second method is based on the micromechanics of plain-woven fabrics. It employs nonlinear kinematics to predict the load-displacement response of a biaxially loaded fabric. Based on the fabric strip model, this method includes the effects of crimp in nonlinear kinematic material behavior and estimates values of effective material properties in tension and shear.

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