Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor | School of Fashion and Textiles | en_US |
| dc.contributor.advisor | Tao, Xiaoming (SFT) | en_US |
| dc.contributor.advisor | Chen, Qingyan (BEEE) | en_US |
| dc.creator | Tang, Shengyang | - |
| dc.identifier.uri | https://theses.lib.polyu.edu.hk/handle/200/13746 | - |
| dc.language | English | en_US |
| dc.publisher | Hong Kong Polytechnic University | en_US |
| dc.rights | All rights reserved | en_US |
| dc.title | Flow in large-area network-structured fluidic fabrics of personal thermal management | en_US |
| dcterms.abstract | With the advancement of human society, more activities under extreme external environments occurs such as firefighting, industrial operations, outdoor building construction, military drills, sports and space exploration. This prompts the development of personal wearable thermal management systems – an innovative multidisciplinary technology for managing body's microclimate. Fluid is a common medium used in wearable management systems. Air-conditioned clothing, water-cooled mattresses, cold/hot therapy machines, spacesuit are typical applications widely used for outdoor body temperature management. | en_US |
| dcterms.abstract | Large-area fluidic fabric heat transfer panels, light in weight, three-dimensionally deformable and good in conformability to curvilinear shapes, are used in wearable devices for thermal management, pain management, sports and injury recovery. However, conventional fabric heat transfer panels comprising single tubes or channels with limited branches have high energy loss, low heat transfer efficiency and high latency in low-high temperature cycles across large areas in a short time span. Inspired by nature, this thesis demonstrates novel structure fluidic fabrics that can self-adjust and homogenize the flow field through an engineered network structure and guide vanes to overcome these shortcomings. | en_US |
| dcterms.abstract | The body-mounted network-structured heat transfer panel can perform two temperatures switching in ~10 s with fast fluid velocity and uniform surface temperature mapping. This study redesigns guide vanes to make the fluid channel with only two major corners to reduce the head loss. Then reinforcement dots are added to form network structures with different parameters and allocate to four different function areas. The guide vanes and reinforcement dots together control the flow rate at different parts and facilitate the heat transfer panel more effective heat distribution with faster flow velocity and uniform temperature mapping. Heat transfer panels for lower limbs are successfully applied to the rapid contrast therapy with temperature switching from 5°C to 40°C for fast sports recovery of elite athletes. | en_US |
| dcterms.abstract | The fluid field in network structures of these fluidic fabrics is analysed by computational fluid dynamics simulations and flow visualization experiments. The simulation results, confirmed by flow visualization experiments, reveal three different flow regimes in network structures. They are pure laminar flow; transitional flow and turbulence dominate transitional flow. A 4-step mass transfer mechanism is proposed: (i) Velocity gradient and vorticity induced rotary mixing and elongation; (ii) Wake alternative vortex shedding induced mixing; (iii) High-pressure region splitting; (iv) Low-pressure region suction. It further explains the long-time flow field homogenization of network structure and the uniform temperature mapping of the wearable heat transfer panels. | en_US |
| dcterms.abstract | The power loss calculations of flow field guide the manipulation of local pressure drops due to inertial and viscous forces in the transitional flow field. The calculation results obtained by energy balance equation show PL4 dominates the total power loss in pure laminar regime while PL3 in transitional flow with more turbulent factors. The two power loss types show equivalent contribution when the flow regime is transitional flow. Also, the flow regime is together affected by the network structure parameters defined as "D", "R" and "r". This further affects the power loss and local pressure drop of different network structures. The calculation promotes the engineering design and optimization of network-structured fluidic fabric heat transfer panels. By allocating network structure appropriately in the four function areas of wearable heat transfer panels, it finally can perform two different temperatures switching in 10 s. | en_US |
| dcterms.extent | xxvi, 210 pages : color illustrations | en_US |
| dcterms.isPartOf | PolyU Electronic Theses | en_US |
| dcterms.issued | 2025 | en_US |
| dcterms.educationalLevel | Ph.D. | en_US |
| dcterms.educationalLevel | All Doctorate | en_US |
| dcterms.accessRights | open access | en_US |
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