Mathematical and experimental analysis of the thermal effectiveness of an oscillating jet with side-to-side swing louvers in a cassette split type air conditioner

Fan, Yunqing

doi:10.1177/1420326x19855418

Cited by 5 publications

(5 citation statements)

References 37 publications

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“…A 360° even jet flow can be provided by a clockwise and/or anticlockwise movement of these four side-to-side swing louvres. 11,31…”

Section: Methodsmentioning

confidence: 99%

“…3 However, HVAC system could be responsible for over 40% of CO 2 emission in the building. 4 Previous research, including field measurements and CFD numerical simulation, have been conducted to develop possible solutions based on various kinds of air distributions such as mixing ventilation, 5,6 displacement ventilation, 7 personalized ventilation, 8 impinging jet ventilation, 9,10 oscillating jet ventilation, 11 stratum ventilation 12,13 and intermittent ventilation 14,15 to provide a better thermal comfort as well as to achieve energy efficiency.…”

Section: Introductionmentioning

confidence: 99%

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A TOPSIS optimization for the indoor thermal environment through oscillating airflow generated from a cassette split type air conditioner

Fan

2020

Indoor and Built Environment

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This study evaluates the feasibility of a control method, ‘the Technique for Order of Preference by Similarity to Ideal Solution’ (TOPSIS) for the optimization of the subzone thermal environment by optimizing the oscillating airflow generated from a cassette split type air conditioner. To address the quasi-dynamic thermal comfort problems, various operation swinging angles of the louvre in the supply opening of an air conditioner and swinging periods were investigated by computational fluid dynamics (CFD) simulation. The impact of air supply control strategies (louvres movement) on the indoor thermal environment was evaluated by multi-criteria operation under quasi-dynamic conditions. The operation parameters were shown to have significantly improved the deviation in thermal uniformity by 16.5% and thermal preference by 7.6%. A 40 s swing period and wider swing angles for the operation of the inner louvre would satisfy the thermal uniformity rather than other alternatives. A shorter swing period <20 s is insufficient to allow perfect airflow mixing at the vertical section. For individual target mode such as the room corner, the thermal performance is more sensitive to the swing angle than the swing period; by increasing the swing angle to ±60° to enhance thermal preference, a 24.1% increase in the overall thermal performance would be achieved.

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“…A 360° even jet flow can be provided by a clockwise and/or anticlockwise movement of these four side-to-side swing louvres. 11,31…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A TOPSIS optimization for the indoor thermal environment through oscillating airflow generated from a cassette split type air conditioner

Fan

2020

Indoor and Built Environment

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“…Wu et al 11 adopted the temperature non-uniformity coefficients of summer and winter to investigate a reasonable air supply and energy-saving method of high-bay depot based on CFD. Fan 12 analysed the impact of air supply control strategies (louvers movement) on indoor thermal environment and evaluated the temperature uniformity using the ADPI to determine the air diffusion performance of a room in heating mode. In a single office full-scale room in isothermal case, Both and Szantho 13 investigated the influence of air diffuser’s offset ratio on air velocity and turbulence intensity distribution by experimental methods.…”

Section: Introductionmentioning

confidence: 99%

Effect of the air supply angle of swirling diffusers on the air diffusion performance index in a vehicle assembly workshop

Wei

et al. 2022

Indoor and Built Environment

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Airflow improvement in a large industrial building is one of the most effective ways to improve the thermal comfort of workers. Air Diffusion Performance Indices (ADPI) of an industrial workshop area under different air supply angles (15°, 30°, 45°, 60°, 75° and 90° in summer and 90° in winter) of the ceiling-mounted swirling diffusers were evaluated by on-site measurements and computational fluid dynamics (CFD) modelling. The measurement data was used to verify the CFD numerical model. The temperature and velocity field of the working area were simulated and analysed under seven operating conditions of swirling diffusers. The findings showed that in summer, the increase of the swirling air supply angle would increase the air velocity. When the air supply angle was larger than 75°, a draughty wind speed (>0.3 m/s) in the local working area, was produced. When the air supply angle was 30°–75°, the indoor design comfortable temperature range (26°C–28°C) was produced. The ADPIs of the workshop were 100% with the air supply angles of 45° and 60° in summer and 90° in winter, respectively. The research findings should provide a reference for improving the airflow organization in the working area of a tall factory building.

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“…A marked characteristic of the beta distribution concerns the parameterization implemented by virtue of certain parameters that exert influence on controlling the shape of the distribution (see Johnson et al 29 for further details). The shape parameters embedded in the beta distribution generate vast multifarious shapes, which can facilitate real‐world usage in many different scenarios 27,31,32 . In particular, the beta distribution with distinct parameter settings can deliver a symmetric, right‐skewed, or left‐skewed distribution; moreover, the adjustment of shape parameters can yield distribution graphs with different heights for peaks and lengths for valleys 30,33 .…”

Section: Introductionmentioning

confidence: 99%

“…Beta distributions enable users or analysts to portray varied probability distributions in down‐to‐earth circumstances because they possess adjustable and variable shapes controlled by parameters. Accordingly, beta distributions can reflect real‐world events and empirical phenomena in practice and have a wide range of applications in various fields 30–32 . Therefore, this paper endeavors to exploit beta distributions to develop a new PF likelihood function for estimating the possibility degrees of outranking and outranked relationships between PF information.…”

Section: Introductionmentioning

confidence: 99%

Pythagorean fuzzy likelihood function based on beta distributions and its based dominance ordering model in an uncertain multiple criteria decision support framework

Tsao

Chen

2021

Int J Intell Syst

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The concept of Pythagorean fuzzy (PF) sets represents a superior tool to model complex uncertainties in an ambiguous and equivocal decision‐making framework. In consideration of the significant capacity for exhibiting the uncertainty of subjective appraisals and estimations under the aegis of the PF theory, this paper presents a simple‐to‐operate decision‐making approach that is grounded in some beneficial concepts of original likelihood functions and measurements of dominating and dominated characters. On the strength of beta distributions, this paper seeks to propound new notions of PF likelihood functions and likelihood‐oriented dominating/dominated characters and to launch an exploitable multiple criteria evaluation method by means of a dominance ordering model for treating decision analysis within PF environments. This paper initiates an efficient beta distribution‐based approach to the construction of novel PF likelihood functions that can quantify the possibility degrees of outranking and outranked relationships between Pythagorean membership grades. The applicable satisfaction and dissatisfaction estimations are established on the likelihood‐oriented dominating and dominated characters, respectively. Furthermore, this paper formulates a straightforward dominance ordering model to obtain the ultimate dominance ranking orders of candidate alternatives and accomplish multiple criteria decision‐making issues involving complicated uncertainty. A financing decision‐making problem concerning working capital requirements is investigated to validate the application results using the advanced methodology. The real‐world application is implemented to examine the reasonableness and efficacy of the established techniques. Moreover, comparative studies through the utility of a sensitivity analysis are performed to demonstrate the efficacy and merits of the dominance ordering model. The comparison results manifest that the initiated methodology is an advantageous and reliable decision‐making technique that can enhance the methodological development regarding the multiple criteria evaluation model under PF uncertainty. Finally, recommendations for future research directions are also presented in the conclusions.

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Mathematical and experimental analysis of the thermal effectiveness of an oscillating jet with side-to-side swing louvers in a cassette split type air conditioner

Cited by 5 publications

References 37 publications

A TOPSIS optimization for the indoor thermal environment through oscillating airflow generated from a cassette split type air conditioner

A TOPSIS optimization for the indoor thermal environment through oscillating airflow generated from a cassette split type air conditioner

Effect of the air supply angle of swirling diffusers on the air diffusion performance index in a vehicle assembly workshop

Pythagorean fuzzy likelihood function based on beta distributions and its based dominance ordering model in an uncertain multiple criteria decision support framework

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