The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Qiuwang Wang - One of the best experts on this subject based on the ideXlab platform.
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Effects of Sealing Strips on shell-side flow and heat transfer performance of a heat exchanger with helical baffles
Applied Thermal Engineering, 2013Co-Authors: Jian-feng Yang, Min Zeng, Qiuwang WangAbstract:In the present paper, numerical simulations are carried out to investigate the effects of number and width of the Sealing Strips on shell-side flow and heat transfer of a shell-and-tube heat exchanger (STHX) with helical baffles. Based on the periodic model, the STHX with discontinuous helical baffles (DCH-STHX) and the STHX with continuous helical baffles (CH-STHX) are investigated under the same helix angle 40° which is the optimal angle proved by the previous research studies. The 320# conductive oil is selected as the working fluid. The results show that under the same mass flow rate M and the width of the Sealing Strips W, with the increase of the number of Sealing Strip, the shell side Nusselt number is 9.3–41.7% higher than that without Sealing Strips while the resistance increases by 37.5–189.7%. Four uniformly distributed Sealing Strips is the optimal structure. Under the same mass flow rate M and the number of Sealing Strip, with the increase of the width of the Sealing Strips W, the Nusselt number increases by 1.6–34.5% while the resistance increases by 11.1–146.6%. The larger width of Sealing Strips, the better heat transfer performance. However, the comprehensive performance j/f decreases with increasing in width and the number of the Sealing Strips. The numerical simulation results also show that the Sealing Strips are more effective to improve the heat transfer performance of the CH-STHX than that of the DCH-STHX, especially in the cases of large mass flow rate.
Jian-feng Yang - One of the best experts on this subject based on the ideXlab platform.
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Effects of Sealing Strips on shell-side flow and heat transfer performance of a heat exchanger with helical baffles
Applied Thermal Engineering, 2013Co-Authors: Jian-feng Yang, Min Zeng, Qiuwang WangAbstract:In the present paper, numerical simulations are carried out to investigate the effects of number and width of the Sealing Strips on shell-side flow and heat transfer of a shell-and-tube heat exchanger (STHX) with helical baffles. Based on the periodic model, the STHX with discontinuous helical baffles (DCH-STHX) and the STHX with continuous helical baffles (CH-STHX) are investigated under the same helix angle 40° which is the optimal angle proved by the previous research studies. The 320# conductive oil is selected as the working fluid. The results show that under the same mass flow rate M and the width of the Sealing Strips W, with the increase of the number of Sealing Strip, the shell side Nusselt number is 9.3–41.7% higher than that without Sealing Strips while the resistance increases by 37.5–189.7%. Four uniformly distributed Sealing Strips is the optimal structure. Under the same mass flow rate M and the number of Sealing Strip, with the increase of the width of the Sealing Strips W, the Nusselt number increases by 1.6–34.5% while the resistance increases by 11.1–146.6%. The larger width of Sealing Strips, the better heat transfer performance. However, the comprehensive performance j/f decreases with increasing in width and the number of the Sealing Strips. The numerical simulation results also show that the Sealing Strips are more effective to improve the heat transfer performance of the CH-STHX than that of the DCH-STHX, especially in the cases of large mass flow rate.
Min Zeng - One of the best experts on this subject based on the ideXlab platform.
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Effects of Sealing Strips on shell-side flow and heat transfer performance of a heat exchanger with helical baffles
Applied Thermal Engineering, 2013Co-Authors: Jian-feng Yang, Min Zeng, Qiuwang WangAbstract:In the present paper, numerical simulations are carried out to investigate the effects of number and width of the Sealing Strips on shell-side flow and heat transfer of a shell-and-tube heat exchanger (STHX) with helical baffles. Based on the periodic model, the STHX with discontinuous helical baffles (DCH-STHX) and the STHX with continuous helical baffles (CH-STHX) are investigated under the same helix angle 40° which is the optimal angle proved by the previous research studies. The 320# conductive oil is selected as the working fluid. The results show that under the same mass flow rate M and the width of the Sealing Strips W, with the increase of the number of Sealing Strip, the shell side Nusselt number is 9.3–41.7% higher than that without Sealing Strips while the resistance increases by 37.5–189.7%. Four uniformly distributed Sealing Strips is the optimal structure. Under the same mass flow rate M and the number of Sealing Strip, with the increase of the width of the Sealing Strips W, the Nusselt number increases by 1.6–34.5% while the resistance increases by 11.1–146.6%. The larger width of Sealing Strips, the better heat transfer performance. However, the comprehensive performance j/f decreases with increasing in width and the number of the Sealing Strips. The numerical simulation results also show that the Sealing Strips are more effective to improve the heat transfer performance of the CH-STHX than that of the DCH-STHX, especially in the cases of large mass flow rate.
Marianne Thunéll - One of the best experts on this subject based on the ideXlab platform.
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A method for evaluating aerosol leakage through the interface between protective suits and full-face respirators.
Journal of occupational and environmental hygiene, 2016Co-Authors: Kristina Arnoldsson, Signar Danielsson, Marianne ThunéllAbstract:ABSTRACTMilitary personnel and first responders use a range of personal equipment including protective suits, gloves, boots, and respirators to prevent exposure of their skin and airways to hazardous chemical, biological, radiological, and/or nuclear substances. Although each individual item of personal protective equipment is well tested against existing standards, it is also necessary to consider the performance of the interfaces between items in terms of prevention from exposure, and the protection system as a whole. This article presents an aerosol challenge method for assessing the performance of the interface between a respirator and the hood of a protective suit. The interface is formed between the Sealing Strip of the hood and the surface of the respirator's outer Sealing area and is affected by how well the Sealing Strip can cover and adapt to the Sealing area. The method evaluates the leakage of particles of different sizes into the hood via the interface by particle counting at sampling points ...
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A method for evaluating aerosol leakage through the interface between protective suits and full-face respirators
2016Co-Authors: Kristina Arnoldsson, Signar Danielsson, Marianne ThunéllAbstract:Military personnel and first responders use a range of personal equipment including protective suits, gloves, boots, and respirators to prevent exposure of their skin and airways to hazardous chemical, biological, radiological, and/or nuclear substances. Although each individual item of personal protective equipment is well tested against existing standards, it is also necessary to consider the performance of the interfaces between items in terms of prevention from exposure, and the protection system as a whole. This article presents an aerosol challenge method for assessing the performance of the interface between a respirator and the hood of a protective suit. The interface is formed between the Sealing Strip of the hood and the surface of the respirator's outer Sealing area and is affected by how well the Sealing Strip can cover and adapt to the Sealing area. The method evaluates the leakage of particles of different sizes into the hood via the interface by particle counting at sampling points around the respirator's perimeter. Three different respirators were tested together with a single hood having a tight-fitting seal. The method variation between measurements was low but increased appreciably when the protective ensemble was re-dressed between measurements. This demonstrates the difficulty of achieving a reliable and reproducible seal between respirator and hood under normal conditions. Different leakage patterns were observed for the three respirators and were linked to some specific design features, namely the respirator's Sealing area at the chin and its width at cheek level. Induced leak experiments showed that to detect substantial particle leakage, channels at the hood-respirator interface must be quite large. The method outlined herein provides a straightforward way of evaluating hood-respirator interfaces and could be useful in the further development of personal protective equipment.
Fabien Moutarde - One of the best experts on this subject based on the ideXlab platform.
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Real-time recognition of human gestures for collaborative robots on assembly-line
2014Co-Authors: Eva Coupeté, Sotiris Manitsaris, Fabien MoutardeAbstract:We present a framework and preliminary experimental results for real-time recognition of human operator actions. The goal is, for a collaborative industrial robot operating on same assembly-line as workers, to allow adaptation of its behavior and speed for smooth human-robot cooperation. To this end, it is necessary for the robot to monitor and understand behavior of humans around it. The real-time motion capture is performed using a "MoCap suit" of 12 inertial sensors estimating joint angles of upper-half of human body (neck, wrists, elbows, shoulders, etc...). In our experiment, we consider one particular assembly operation on car doors, which we have further subdivided into 4 successive steps: removing the adhesive protection from the waterproofing sheet, positioning the waterproofing sheet on the door, pre-sticking the sheet on the door, and finally installing the window "Sealing Strip". The gesture recognition is achieved continuously in real-time, using a technique combining an automatic time-rescaling similar to Dynamic Time Warp (DTW), and Hidden Markov Model (HMM) for estimating respective probabilities of the 4 learnt actions. Preliminary evaluation, conducted in real-world on an experimental assembly cell of car manufacturer PSA, shows a very promising action correct recognition rate of 96% on several repetitions of the same assembly operation by a single operator. Ongoing work aims at evaluating our framework for same actions recognition but on more executions by a larger pool of different human operators, and also to estimate false recognition rates on unrelated gestures. Another interesting potential perspective is the use of workers' motion capture in order to estimate effort and stress, for helping prevention of physical causes of some musculoskeletal disorders.