Jet Mode Research Articles

An Adaptive Approach in Polymer-Drug Nanoparticle Engineering using Slanted Electrohydrodynamic Needles and Horizontal Spraying Planes.

The present study focuses on the adaptive development of a key peripheral component of conventional electrohydrodynamic atomisation (EHDA) systems, namely spraying needles (also referred to as nozzles or spinnerets). Needle geometry and planar alignment are often overlooked. To explore potential impact, curcumin-loaded polylactic-co-glycolic acid (PLGA) and methoxypolyethylene glycol amine (PEG)-based nanoparticles were fabricated. To elucidate these technological aspects, a horizontal electrospraying needle regime was adapted, and three formulations containing different polymeric ratios of PLGA: PEG (50:50, 75:25, and 25:75) were prepared and utilised. Furthermore, processing head tip geometries e.g.blunt (a flat needle exit) or slanted (a 45° inclination angle), were subjected to various flow rates (5 µL-100 µL). Successful engineering of curcumin-loaded polymeric nanoparticles (< 150nm) was observed. In-silico analysis demonstrated stable properties of curcumin, PEG and PLGA (molecular docking studies) and fluid flow direction towardsthe Taylor-Cone (also known as the stable jet mode), was shownby the assessment of fluid dynamics simulations in various needle outlets. Curcumin-loaded nanoparticles were characterised using an array of methods including Scanning electron microscopy, Differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, as well as their contact angles, encapsulation efficiencies and finally release patterns. The discrepancy when spraying with blunt and angled needles was evidenced by electron micrographs and deposition patterns. Spraying plumes utilising slanted needles enhanced particle collection efficiency and distribution of resultant atomised structures. In addition to needle design, fine-tuning the applied voltage and flow rate impacted the electrospraying process. The coefficient of variation was calculated as 30.5% and 25.6% for blunt and angled needle outlets, respectively, presenting improved particle uniformity with the employment of angled needle tips (8-G needle at 25 µL). The interplay of processing parameters with the utilisation of a slanted exit at a capillary optimised the spray pattern and formation of desired nanoparticulates. These demonstrate great applicability for controlled deposition and up-scaling processes in the pharmaceutical industry. These advances elaborate on EHDA processes, indicating a more cost-effective and scalable approach for industrial applications, facilitating the generation of a diverse range of particle systems in a controlled and more uniform fashion.

Upstream velocity fields induced by frontal jet injection in a square cylinder

The flow characteristics around the frontal face of a square cylinder with a frontal jet injection were experimentally studied in a closed-loop wind tunnel using the PIV technique. Four characteristic flow modes were identified based on the injection ratio: swinging jet, deflected oscillating jet, deflection jet, and penetrating jet. At low injection ratio, the flow mode denoted as the swinging jet is characterised by two recirculation regions and a four-way saddle point. At moderate injection ratio, the flow mode termed deflected oscillating jet is characterised by a recirculation region and a counterclockwise rotating vortex within the recirculation region. At moderately high injection ratio, the flow mode is denoted as deflection jet, where a clockwise rotating vortex appears in the flow field. At high injection ratio, the flow mode is termed as penetrating jet, with no vortex formation in the flow field. The strength of the turbulence intensities increases considerably with high injection ratios. The time histories of instantaneous velocity for non-injection case, swinging jet, and deflected oscillating jet modes show periodic oscillations, whereas those of deflection jet and penetrating jet modes do not show periodic oscillations. The study presents and discusses the time-averaged velocity vectors, and streamlines, vorticity contours, velocity properties, velocity time histories, and power spectral density function under different flow modes.

Baby’s first jets: a kinematic and hydrodynamic analysis of turning in cuttlefish hatchlings

AbstractTurning is an important aspect of life underwater, playing integral roles in predator avoidance, prey capture, and communication. While turning abilities have been explored in a diversity of adult nekton, little is currently known about turning in early ontogeny, especially for cephalopods. In this study, we investigated the turning abilities of hatchling common cuttlefish (Sepia officinalis, n = 49) and dwarf cuttlefish (Sepia bandensis, n = 30), using both kinematic and wake-based analyses. Using body tracking software and particle image velocimetry (PIV), we found that S. officinalis turned faster than S. bandensis, but both species completed equally tight turns. Orientation (arms-first or tail-first) did not have a significant effect on turning performance for either species. Cuttlefish hatchlings used multiple short jets for more controlled turning, with jet mode I (isolated vortex rings) being 3–4 times more common than jet mode II (elongated jets with leading ring structures) for both species. While both hatchlings turned more broadly than adult squid and cuttlefish, S. officinalis hatchlings turned faster than adult cuttlefish, and both hatchlings turned more tightly than other jet-propelled animals and some non-jet-propelled swimmers.

Evolution from a guided-streamer mode to a continuous-discharge mode in an atmospheric pressure argon plasma jet

Atmospheric pressure plasma jet (APPJ) has attracted much attention due to its versatile applications in various fields, which normally operates in either a guided-streamer mode or a continuous-discharge mode. In this paper, temporal evolution is observed from the guided-streamer mode to the continuous-discharge one in an argon APPJ excited by a sinusoidal voltage. Waveforms of voltage and current indicate that the voltage applied to the electrode is distorted severely from the ideal sine. For the guided-streamer mode, there is only one discharge pulse per half voltage cycle. For the mode transition or the continuous-discharge mode, there is only one discharge composed of a pulse and a hump per half voltage cycle. Fast photography implemented for the mode transition reveals that both the discharges in the positive and the negative voltage polarities evolve from the guided-streamer mode to the continuous-discharge one. In the guided-streamer mode of the mode transition, the discharge behaves as a positive streamer in the positive voltage polarity, while a negative streamer in the negative voltage polarity. In addition, the mode transition only occurs in a range of dissipated power and gap width. Based on optical emission spectroscopy, temporal evolutions of the mode transition are investigated for excited electron temperature, electron density, and field strength. Moreover, their spatial distributions along the argon stream are studied at different time instants. These results are of great importance for the discharge dynamics of APPJ.

On the origin of star formation quenching in massive galaxies at ≳ in the cosmological simulations IllustrisTNG

ABSTRACT Using the cosmological simulations IllustrisTNG, we perform a comprehensive analysis of quiescent, massive galaxies at $z \gtrsim 3$. The goal is to understand what suppresses their star formation so early in cosmic time, and how other similar mass galaxies remain highly star forming. As a first-order result, the simulations are able to produce massive, quiescent galaxies in this high-redshift regime. We find that active galactic nucleus (AGN) feedback is the primary cause of halting star formation in early, massive galaxies. Not only do the central, supermassive black holes (SMBHs) of the quenched galaxies have earlier seed times, but they also grow faster than in star-forming galaxies. As a result, the quenched galaxies are exposed to AGN feedback for longer, and experience the kinetic, jet mode of the AGN feedback earlier than the star-forming galaxies. The release of kinetic energy reduces inflows of gas while likely maintaining outflows, which keeps a low cold gas fraction and decreases the star formation of the galaxies down to a state of quiescence. In addition to AGN feedback, we also investigate the influence of the large-scale environment. While mergers do not play a significant role in the quenching process, the quenched galaxies tend to reside in more massive haloes and denser regions during their evolution. As this provides a greater initial amount of infalling gas to the galaxies, the large-scale environment can mildly affect the fate of the central SMBH growth and, via AGN feedback, contribute to star formation quenching.

Influence of electrode transparency on the plasma properties of a cylindrical IEC plasma source

This study investigates the influence of cathode and anode grid transparency on the plasma properties of a Cylindrical Inertial Electrostatic Confinement plasma source. The primary focus is to elucidate how variations in the transparency of the electrodes impact plasma characteristics and the operational performance of the source, particularly during spray jet mode. Employing optical emission spectroscopy (OES) and Langmuir probe diagnostics, the plasma behavior is analyzed comprehensively. The results demonstrate that cathode transparency has a pronounced effect on discharge current and plasma density within the cathode. Conversely, the transparency of the anode has only a little influence the ignition characteristics and operational stability of the plasma source. The findings highlight the importance of utilizing cathode transparency to adjust both the pressure and voltage operating ranges of the IEC source in spray jet mode, optimizing its performance for various applications.

Dynamics of the air bubble on the upper surface of a plate: Influences of the cavitation bubble

The interaction of laser-induced cavitation bubbles with air bubbles attached to the upper surface of a horizontal plate was studied with high-speed photography. On the cavitation bubble side, the dimensionless distance parameter, γ=4.5 for vertical jets from cavitation bubbles as proposed in previous research and the dimensionless parameter, γ=5.8 for oblique upward jets have been established. On the attached air bubble side, the relationship between the dimensionless distance parameter, γa and the four types of morphology (Omega, hemisphere, hemisphere to hat with split, and hemisphere to hat without split) of attached air bubbles, as well as the three modes of jets (initial, multiple, and delay), has been demonstrated. The split of the small bubble from the attached bubble is primarily due to the vertical velocity differences brought about by the multiple collapses of cavitation bubbles and the pulsation of attached bubbles. Subsequent studies on the detachment behavior of attached bubbles determined the ideal dimensionless distance, γa=3.4 for detachment. The surface ripples play a dominant role in promoting the detachment of attached bubbles at greater distances.

Unsteadiness in vacuum ejector and their sources

This study investigates unsteadiness in the secondary chambers of a vacuum ejector during its transient startup phase. Experiments reveal unsteadiness at various frequencies across different nozzle pressure ratios. These frequencies are categorized as symmetric (in-phase) or asymmetric (counter-phase) through cross-spectral phase analysis. Dynamic mode decomposition, using time-resolved schlieren images, elucidates the corresponding flow structures and acoustic fields. The mode shapes display alternating density gradients along both the longitudinal and lateral axes, which explain the oscillatory behavior of the jet. These oscillations arise from instabilities in the jet's shear layer and acoustic disturbances due to the jet being confined within a duct. Using empirical relations, spectrogram analysis, time-resolved schlieren imaging, and classical wave theory, the sources of unsteadiness in the secondary chamber are identified as jet screech, its harmonics, and modes due to duct acoustics (symmetric and asymmetric). Additionally, the screech feedback loop in the vacuum ejector is found to be distinct from that in open jets, and the effect of screech on duct-mode acoustics is also observed.

Coaxial air blast atomization of a particulate gel suspension jet

The objective of this study is to experimentally and theoretically explore the impact of particle volume fractions and nozzle thread structure on the coaxial air blast atomization of particulate gel suspension jets through the high-speed flow visualization technology. The four breakup modes of particulate gel suspension jets are confirmed, namely oscillation mode, membrane-type breakup, fiber-type breakup, and superpulsating submode. However, the fiber-type breakup of jets disappears as the particle concentration reaches 40%, primarily attributed to the numerous particles sharply promoting the instability on the free jet surface. The experimental statistical results demonstrate that an increase in particle concentration and the adoption of the threaded nozzle both result in an expansion of the jet spray angle. The breakup length exhibits a reduction trend with the increase of particle concentration. However, it remains nearly the same value as that in the case of volume fraction 20% when the particle concentration continues to increase, contributed by the surge of viscous dissipation counteracting the enhanced instability on the jet interface caused by a large number of particles. The breakup length of a pure gel jet is predicted through the linear instability analysis, which is further modified by the viscosity model of particle suspensions to derive the breakup lengths of particulate gel suspension jets with different concentrations. The theoretical predictions align well with the statistical results in the experiment. The research is poised to have potential implications for numerous industrial processes and engineering applications including gel propellants.

Correction of Aero-Optical Effect with Blow–Suction Control for Hypersonic Vehicles

High-speed turbulence induces significant aero-optical effects that severely disrupt the functionality of imaging systems of hypersonic vehicles. In this study, the aero-optical correction of various jet cooling modes is investigated using a Terminal High Altitude Area Defense (THAAD)-like seeker model and the imaging impact of high-speed flow field and flow control on the optical window is analyzed by the Delayed Detached Eddy Simulation (DDES) method. The findings reveal that a jet mode parallel to the window exhibits better cooling effectiveness compared to a perpendicular jet mode along the body axis; however, it introduces additional wavefront distortion, leading to degraded imaging quality. Although micro-vortex generators (MVGs) can reduce density fluctuations near the window from a refractive index perspective, they do not effectively mitigate wavefront distortion or improve window cooling efficiency. Finally, incorporating suction control, a comprehensive flow control solution, significantly improves the flow field structure near the window, resulting in a more uniform temperature distribution and reduced wavefront distortion. Applying this flow control method results in a 14.7% reduction in wavefront distortion at 3 Ma and an approximately 20% maximum value reduction at 5 Ma. This study proposes a novel and comprehensive flow control method to effectively mitigate the aero-optical effect in hypersonic flows, providing a new avenue for subsequent researchers in this field.

Flowfield and Noise Dynamics of Supersonic Rectangular Impinging Jets: Major versus Minor Axis Orientations

The current study explores the flowfield and noise characteristics of an ideally expanded supersonic (Mach 1.44) rectangular jet impinging on a flat surface. The existing literature is primarily concentrated on axisymmetric jets, known for their resonance dominance, pronounced unsteadiness, and acoustic signatures. In contrast, non-axisymmetric jets remain relatively less understood, particularly those impinging on a ground surface. By employing Schlieren imaging, high-frequency pressure measurements using high-bandwidth transducers, and particle image velocimetry (PIV), this research comprehensively examines the flow-acoustic phenomena. Schlieren imaging revealed distinct, coherent structures and strong acoustic waves, while pressure measurements at the impingement surface exhibited high-amplitude fluctuations, peaking at approximately 186 dB. Acoustic analysis identified multiple high-amplitude tones with unique directional characteristics, suggesting the potential for multiple simultaneous modes in rectangular jets. Furthermore, the PIV data elucidated differences in the jet shear layer and wall jet development attributed to the nozzle orientation. These findings contribute to a deeper understanding of non-axisymmetric jet behavior, offering insights relevant to fundamental flow physics and practical applications such as vertical takeoff and landing aircraft.

Stable generation of Core-Shell droplets in Coaxial Electrohydrodynamic Printing by Numerical Simulation and Jet Mode Recognition

Stable generation of Core-Shell droplets in Coaxial Electrohydrodynamic Printing by Numerical Simulation and Jet Mode Recognition

Unravelling jet quenching criteria across L* galaxies and massive cluster ellipticals

ABSTRACT In the absence of supplementary heat, the radiative cooling of halo gas around massive galaxies (Milky Way mass and above) leads to an excess of cold gas or stars beyond observed levels. Active galactic nucleus jet-induced heating is likely essential, but the specific properties of the jets remain unclear. Our previous work concludes from simulations of a halo with $10^{14} \,\mathrm{ M}_\odot$ that a successful jet model should have an energy flux comparable to the free-fall energy flux at the cooling radius and should inflate a sufficiently wide cocoon with a long enough cooling time. In this paper, we investigate three jet modes with constant fluxes satisfying the criteria, including high-temperature thermal jets, cosmic ray (CR)-dominant jets, and widely precessing kinetic jets in $10^{12}-10^{15}\, {\rm M}_{\odot }$ haloes using high-resolution, non-cosmological magnetohydrodynamic simulations with the FIRE-2 (Feedback In Realistic Environments) stellar feedback model, conduction, and viscosity. We find that scaling the jet energy according to the free-fall energy at the cooling radius can successfully suppress the cooling flows and quench galaxies without violating observational constraints. On the contrary, if we scale the energy flux based on the total cooling rate within the cooling radius, strong interstellar medium cooling dominates this scaling, resulting in a jet flux exceeding what is needed. Among the three jet types, the CR-dominant jet is most effective in suppressing cooling flows across all surveyed halo masses due to enhanced CR pressure support. We confirm that the criteria for a successful jet model work across a wider range, encompassing halo masses of $10^{12}-10^{15} {\rm M_\odot }$.

Pinch-off dynamics of an electrohydrodynamic tip streaming jet transforming into the microdroplet

The drop-on-demand electrohydrodynamic (EHD) printing is promising for manufacturing high-resolution dot arrays. Such dot fabrication is commonly achieved through two printing modes (jet/droplet mode), i.e., continuous jet directly flying to or broken jet induced droplet depositing in the substrate. The droplet mode commonly has a higher printing frequency than the jet mode, indicating the droplet mode's advantage in drop-on-demand EHD printing. However, most research on EHD printing focuses on the jet mode, which causes the mechanism of droplet production through jet pinch-off remains unclear. This study employs an arbitrary Lagrangian–Eulerian method capable of getting a sharp interface to reveal the pinch-off mechanism. First, the development of a tip streaming from a meniscus to the pinch-off is analyzed. It is found that the high pressure at the neck is the main reason for the pinch-off of the jet into the droplet. Second, the EHD phase diagram in the parameter space of We–Cae is plotted, where We is the Weber number and Cae is the electric capillary number. Finally, the important influences of the charge relaxation on the EHD tip streaming jet's breakup behavior and the generated droplets' properties are revealed. Evolutions of the droplet's properties, including radius, velocity, and charge, with varying charge relaxation parameters are offered. These properties of the droplet show their relationships with extreme values as a function of the charge relaxation parameter. This work can serve as the theoretical basis for tuning the EHD printing manufacturing performance.

The Role of Active Galactic Nucleus Winds in Galaxy Formation: Connecting AGN Outflows at Low Redshifts to the Formation/Evolution of Their Host Galaxies

Using Sloan Digital Sky Survey (SDSS) spectra, we applied an automatic method to search for outflows (OFs) in three large samples of narrow-line active galactic nuclei (AGN) at low redshifts (z < 0.4), separated into three spectral activity classes: radio-loud galaxies (RGs), 15,793; radio-quiet Seyfert 2 AGN (Sy2), 18,585; and LINERs, 25,656. In general, the probability of detecting an OF decreases along the sequence Sy1→Sy2→LINER/RG and independently of the AGN class, the wind velocity, traced by W80, increases with the AGN luminosity. Moreover W80 is systematically higher in RGs or any of the other AGN classes when detected in radio. These results support the idea that there are two main modes of production of OF, the radiative mode dominant in radio-quiet AGN and the jet mode dominant in RGs, although both modes could also happen simultaneously at different levels. From the spectra and SDSS photometry, the characteristics of the AGN host galaxies and their supermassive black holes (SMBHs) were also retrieved using the stellar population synthesis code STARLIGHT. This revealed that, independently of the AGN spectral class, (1) galaxy hosts with OFs have systematically later morphological types and higher star formation rates (SFRs) than their counterparts without OF, (2) the AGN occupy different positions in the specific diagnostic diagram (specific black hole accretion rate (sBHAR) versus specific SFR), which suggests they follow different evolutionary paths congruent with the morphology of their galaxy hosts, and (3) they show no evidence of AGN quenching or triggering of star formation. These results are consistent with a scenario explaining the different AGN classes as consequences of different formation processes of galaxies: early-type galaxies (LINERs and RGs) formed bigger bulges and more massive SMBHs, exhausting their reservoir of gas more rapidly than late-type galaxies (Sy2 and Sy1), and thereby quenching their star formation and starving their SMBHs.

Coordination of water jets and electron beams for dual-beam high-speed wastewater treatment

A new irradiator design for large-scale dual-beam wastewater treatment in jet mode is proposed and analyzed. A combination of technical solutions previously used separately in the design of the ELV-12 and Electron-10 accelerators is considered. Accelerating tubes are used to produce bifurcated beams. Each half-beam is bent by 90° and directed towards the half-beam produced from the adjacent accelerating tube. The water jet is irradiated from both sides in the gap between the beam windows at a speed above 1 m s−1. The electron beams are oriented at an angle of 45–60° to the direction of the water jet. The angle causes a decrease in the useful thickness of the jet, but an increase in the depth dose in the cross section of the jet. Options for simultaneous irradiation of two and four water jets are considered.

Effect of impinging jet on rapid cooling of a miniature Joule-Thomson cryocooler: Experimental study of operating conditions

A miniature open-cycle Joule-Thomson (J-T) cryocooler possesses excellent potential for rapid cooling from ambient temperature to about 100 K within seconds. In this rapid cooling process, the interplay of the heat transfer process between the cryogenic fluid and the cold plate plays a crucial role, in addition to the J-T effect and the energy recovery within the heat exchanger of the cryocooler. The phase state of the impinging jet is determined by the jet temperature and has different heat transfer mechanism. To investigate this impinging jet behavior separately, an experimental system for the rapid cooling J-T cryocooler was set up and the jet temperature was measured besides other important parameters. The operating conditions, including the cylinder pressure, cylinder volume, ambient temperature, and the refrigerant, were studied orthogonal. It was observed that argon, compared to nitrogen, can be more rapidly throttled into its two-phase region within a second. However, nitrogen will perform better than argon in terms of cool-down time. This is attributed to the temperature difference between the jet and the cold plate, which significantly influences the boiling mode of the two-phase jet, and in turn affects the cryocooler's cooling rate. Nevertheless, due to the smaller heat transfer intensity of single-phase jet, the cool-down time of nitrogen deteriorates quickly at high ambient temperatures. Experimental results also revealed that the cooling rate of the cryocooler still can be enhanced even if cylinder pressure beyond its saturation curve, caused by the dynamic cooling process and the pressure drop within the finned tube.

Numerical simulation of the liquid film thickness distribution of horizontal tubes under cross-airflow

During the working process of the falling film evaporator, the airflow generated by evaporation process affects the falling film flow process. A three-dimensional model consisting of two horizontal tubes was conducted, which only considered the flow of one liquid column unit. The effect of cross-airflow on the liquid film thickness distribution of tube 1 and tube 2 in the jet mode was studied. The gas is air, the liquid is pure water, and the flow of gas and liquid begins simultaneously. The fluctuation and thickness distribution of the liquid film were analyzed. The research results indicate that liquid film fluctuation occur at the moment when the fluid falls from the first tube to the second tube, and continue to exist thereafter. When the airflow is applied, at l*=0.5, for the tube 1, the liquid film thickness from θ=45° to 90° areas is relatively flat; At l*=1, for the tube 2, the smallest liquid film thickness is located near θ=90° and 270°. The airflow has a certain inhibitory effect on the liquid film waviness on the windward side. The main reason why the liquid film thickness on the leeward side is greater than that on the windward side is due to the offset of the liquid column. The stability of the liquid column, which means that the liquid column does not offset, can ensure the stability of the falling film flow process.

Experimental investigation of the structure of plane turbulent wall jets. Part 1. Spectral analysis

Plane turbulent wall jets are traditionally considered to be composed of a turbulent boundary layer (TBL) topped by a half-free jet. However, certain peculiar features, such as counter-gradient momentum flux occurring below velocity maximum in experiments and numerical simulations, suggest a different structure of turbulence therein. Here, we hypothesize that turbulence in wall jets has two distinct structural modes, wall mode scaling on wall variables and free-jet mode scaling on jet variables. To investigate this hypothesis, experimental data from our wall jet facility are acquired using single hot-wire anemometry and two-dimensional particle image velocimetry at three nozzle Reynolds numbers 10 244, 15 742 and 21 228. Particle image velocimetry measurements with four side-by-side cameras capture the longest field of view studied so far in wall jets. Direct spatial spectra of these fields reveal modal spectral contributions to variances of velocity fluctuations, Reynolds shear stress, shear force, turbulence production, velocity fluctuation triple products and turbulent transport. The free-jet mode has wavelengths scaling on the jet length scale ${z_{T}}$ , and contains two dominant submodes with wavelengths $5{z_{T}}$ and $2.5{z_{T}}$ . The region of flow above the velocity maximum shows the presence of the outer jet mode whereas the region below it shows robust bimodal behaviour attributed to both wall and inner jet modes. Counter-gradient momentum flux is effected by the outer jet mode intruding into the region below velocity maximum. These findings support the hypothesis of wall and free-jet structural modes, and indicate that the region below velocity maximum could be much complex than a conventional TBL.

Diffusion characteristics of vertical oxygenic-thermal coupled jet and indoor oxygenic-thermal environment regulation in high-altitude areas

The Qinghai-Tibet Plateau has typical climatic phenomena such as low temperatures and oxygen deficiency, which have a great impact on the health of local residents. In order to improve the indoor oxygenic-thermal environment, this paper explored the flow characteristics of a vertical oxygenic-thermal coupled jet by CFD numerical simulation and experimental verification in high-altitude areas. The results found that the oxygenic-thermal diffusion range moved up by 0.17m–1.02 m in the vertical direction as the jet temperature increased by 3K–9K, and this process could enhance the synergistic effect of the oxygenic-thermal diffusion, while the oxygen flow supply reduced this effect, and the diffusion range shifted down by 0.87m–1.90 m as the jet oxygen concentration increased by 20%–60%. The indoor airflow uniformity with ΔT = 3K was more desirable than that with ΔT = 9K, and a high oxygen concentration was detrimental to temperature elevation, so a slight variation in temperature and concentration could be selected when meeting the demand for indoor heating and oxygen supply. The air inlet position has a more significant effect on the thermal environmental distribution than the oxygen environment, and the coupled airflow non-uniformity coefficient is minimized when the air inlet is located at the top center of the room. This study would provide some recommendations for regulating the indoor oxygenic-thermal environment in high-altitude areas under vertical jet mode.