A Numerical and Experimental Investigation of a Confluent Jets Ventilation Supply Device in a Conference Room

Abstract

In this study, confluent jets ventilation (CJV) supply devices with three different nozzle arrays (1 × 19, 2 × 19, 3 × 19) were investigated both numerically and experimentally at two different airflow and supply air temperature set-ups. The performance of the CJV supply devices was investigated concerning thermal comfort, indoor air quality (IAQ), and heat removal effectiveness in a conference room environment. A comparison between the experimental and numerical results showed that the ϑ2¯−f model had the best agreement out of the investigated turbulence models. The numerical results showed that the size of the array had a great impact both on near-field development and on the conditions in the occupied zone. A larger array with multiple rows and a lower momentum conserved the inlet temperature and the mean age of the air better than a single-row array with a higher momentum. A larger array with multiple rows had a higher IAQ and a greater heat removal effectiveness in the occupied zone because the larger array conserved the mean age of air better and the buoyancy driven flow was slightly better at removing the heat. Because of the lower inlet velocities, they also had lower velocities at ankle level, which decreased the risk of draft and thermal discomfort.

Eddy–Viscosity Reynolds-Averaged Navier–Stokes Modeling of Air Distribution in a Sidewall Jet Supplied into a Room

“…Selected representative studies conducted in this area in the last few years are presented in Table 2. LES is in better agreement with measurements than RANS and URANS Kang and van Hooff (2022) [33] Non-isothermal side-wall jet Two opposing plane wall jets in an empty airplane cabin In the studies presented in Table 2 and within several older papers, the air movement in the room was caused by air jets such as plane jets [41,46], plane wall jets [31,34,36,38,39,46], 3D circular quasi-free sidewall jets [32,33,42,44], impinging jets [37,40,43], slightly swirling free jets [45], and confluent jets [47]. In order to validate the CFD results in the jet zone, the air velocity measurements were performed using LDA [32,40,41,44,45], a hot-wire anemometer [40,42], a three-hot-wire anemometer [33], PIV anemometry [34,37,41], a low-velocity thermal anemometer (LVTA) [38], and an ultrasonic anemometer [40].…”

Sustainable Buildings: Heating, Ventilation, and Air-Conditioning

“…Here, we provide a brief review of the articles [7][8][9][10][11][12][13][14] published in the Special Issue. A graphical summary of the key areas covered in the Special Issue is shown in Figure 2.…”

“…In their recent study, Andersson et al ( 2022) [8] developed a numerical model to evaluate further the performance of ceiling-mounted confluent jet ventilation supply devices. The study investigated the impact of design and operation parameters on comfort, air quality, and heat removal efficiency.…”