Optimum Air Flow Rate Research Articles

Thermo-Economic Analysis of Thermoelectric-Based Atmospheric Water Harvesters: Flow Configuration Impacts

In recent years, thermoelectric cooling has seen significant growth, driven by advancements in nanoscience and manufacturing. Concurrently, the increasing water crisis in various regions has led to a surge in research on Atmospheric Water Harvesters (AWHs) for decentralized water harvesting. This study presents a comprehensive thermodynamic and economic analysis of Thermoelectric-based Atmospheric Water Harvesters (TAWHs) with different Heat Exchanger (HX) configurations with different flow configurations. Our research identifies five types of HXs, each characterized by its own optimal geometrical and controlling parameters. These HXs are evaluated based on economy, eco-friendliness, productivity, air cooling efficiency, and compactness. We provide new insights into the hidden potential and performance of Thermoelectric Coolers (TECs) in desalination, particularly highlighting the effect of increasing the ratio of surfaces mounted with TECs to the total surface area of the channels. Our results indicate that among the HX configurations, the counter flow HX is the most economical option, capable of water harvesting at a cost of $0.230 USD per liter from an 80% humidity level. The parallel flow HX demonstrates higher efficiency according to the second law of thermodynamics and environmental friendliness, while the crossflow HX exhibits lower overall efficiency. We found that the optimum cold channel incoming air flow rate varies with humidity in a detailed analysis of a counter flow HX with 2 columns and 15 rows. Interestingly, we found that humidity and incoming air mass flow rate have a negligible effect on power consumption. This work can be used as a guideline for future engineering problems involving the design and optimization of TAWHs.

ANALYSIS OF MICRO GAS TURBINE PERFORMANCE USING MODELLING APPROACH

Micro-gas turbine (MGT) is compact and self-sufficient distributed power generation units that exhibit reliability and has the capability to mitigate carbon monoxide (CO) emissions while conserving energy together with biomass used as a fuel sources. It is expected that they will have a noteworthy impact on securing the provision of upcoming energy resources for isolated areas, disaster condition and off-grid zone regardless of their connection to the power grid. However, the MGT performance using the various fuel still questionable. Databases and procedure of the MGT performance analysis should be established well to understand the overall MGT performance. In this study, MGT performance is determined by utilising the computer aided design (CAD) and solver software such as SOLIDWORKS and ANSYS-FLUENT. CAD drawing is used to design the combustion chamber and simulation performance is visualised in specific inside the combustion chamber (CC) of the MGT. The solver software was employed for the purpose of conducting computational fluid dynamics (CFD) analyses. The optimal configuration contained a flame holder with a diameter of 50 millimetres, a chamber height of 60 centimetres, four holes with diameters of 6, 8, and 10 millimetres, and a dead zone separating the combustion and dilution zones. The air inlet boundary conditions were established by utilising the specifications and compressor maps of the Garrett GT25 turbocharger in the simulation. The simulation employed the standard k-ε model of viscous model and energy equation to establish an optimal maximum airflow rate of 0.15 kg/s at a pressure of 1.4 bar, resulting in a compressor efficiency of approximately 70%. Three different fuels, diesel-air, wood-volatiles-air, and coal-hv-volatile, were used to determine the MGT's optimal performance. Successful investigation of this study opts to significant contribution to understand the MGT performance thus, give the awareness to choose as one of the alternative power generations which can be used in the future.

Numerical simulation of the dust pollution characteristics and the optimal dustproof air volume in coal washing plant screening workshop

Dust pollution generated during the working process of a screening workshop in a coal washing plant seriously threatens the occupational health of workers. To improve the working environment for workers, we investigated the effects of various airflow parameters on the diffusion of dust particles and pollutants. We established a proportional model of the screening workshop and conducted spatiotemporal analysis of the evolution laws of airflow and particulate matter. We used numerical simulation and on-site measurements to obtain the optimal dust removal air flow rate in a coal washing plant workshop. When the air flow rate is between 360 and 1260 m³/min, the overall dust concentration in the workshop and the average dust mass concentration in the breathing zone decrease significantly as the air flow rate increases. However, if the air flow rate is too high, this can cause re-entrainment of dust, which will pollute the operation area again. The optimum dust removal airflow for the inlet air was 1260 m³/min. This air flow rate decreases the dust at the height of the breathing zone in the working area, and the dust concentration at the sidewalk in the working area decreases by 58.82%. This air flow rate can act as a reference value for workshop ventilation design to provide a clean and safe production environment for coal miners. Our methodology and results are of value the formulation and development of effective dust control and clean production technologies.

Thermal performance of a novel underground energy migration system for greenhouse

The progression of Chinese solar greenhouse is shifting from an integrated insulation and heat storage system to a separated configuration. Retaining a significant amount of surplus air thermal energy during the day, it can be stored and released at night to meet heating demands. To effectively utilize the surplus air thermal energy, an underground energy migration system is proposed for storing it. The thermal environment of the greenhouse is analyzed in experiments after applying the system, and the required thermal performance for the system’s heating is calculated using the greenhouse’s thermal balance. A computational fluid dynamics method is employed to optimize the system while also determining the system’s impairing effect on the greenhouse’s thermal environment. The findings suggest that the insulation of heat storage units must be externally maintained to prevent soil interference with the system’s thermal performance. The optimal airflow rate for heat storage was 2 ∼ 2.5 m/s, and 2.5 ∼ 3 m/s for heat release. The average air temperature of greenhouse decreases 1.80 °C in daytime and increases 2.14 °C in nighttime by the underground energy migration system. Meanwhile, the heating coefficient of performance reaches 5.14. The system provides new ideas and methods for the recycling of clean energy in greenhouses.

Kinetic model of grating-like DBD fed with flowing humid air

This work proposes a coupled kinetic model to capture the spatiotemporal evolution behaviors of reactive species generated by a grating-like dielectric barrier discharge (DBD) operated in flowing humid air. The coupled model incorporates a zero-dimensional (0D) discharge model for the discharge filament and a 0D kinetic model or two-dimensional (2D) fluid model for the afterglow region. The model is experimentally validated by the ozone measurements under different airflow rates and power levels. With the pseudo-1D plug flow approximation, the spatial distribution of species obtained by the 0D afterglow model agrees well with the 2D fluid model. The kinetics of reactive oxygen and nitrogen species in the discharge and afterglow region and the underlying pathways are analyzed. It is predicted by the model that there exists an optimal discharge power or airflow rate to acquire a maximum density of short-lived species (OH, O2(a1Δ), HO2, etc) delivered to a given location in the afterglow region. The key factor influencing the plasma chemistry is discharge power, regardless of initial species density, and less concerned with pulse width. The proposed model provides hints for a better understanding of DBD-relevant plasma chemistry operated in ambient air.

Control of Aerodynamic Characteristics of Thick Airfoils at Low Reynolds Numbers Using Methods of Boundary Layer Control

The article explores flow behavior around thick airfoils at low Reynolds numbers and the potential application of energy methods to manipulate the flow field for increased lift and reduced drag. The study relies on a set of propulsion airfoils calculated using a combined approach of solving the inverse problem of aerodynamics and applying stochastic global optimization methods. The calculations consider the transition from laminar to turbulent flow regimes, which significantly affects lift and airfoil drag. The suitability of different turbulence models for airfoil modeling in low Reynolds numbers is discussed, and numerical simulation results determine the lift coefficient dependence on angle of attack and the optimal air flow rate taken from the airfoil surface for each angle of attack. The accuracy of different turbulence models is analyzed by comparing numerical simulation results to physical experiment data.

Evaluation of Phase Change Materials for Pre-Cooling of Supply Air into Air Conditioning Systems in Extremely Hot Climates

This research investigates the use of phase change materials (PCMs) in thermal energy storage (TES) unit-based cooling systems to increase the efficiency of air conditioners (ACs) by reducing the air inlet temperature. This study aims to evaluate different configurations of PCM enclosures, and different PCMs (paraffin and salt hydrate), by changing the speed of inlet air to achieve heat reduction of inlet air. The study includes experimental and simulation investigations. Every configuration simulates the hot-season atmospheric conditions of the UAE. A duct containing enclosures of paraffin RT-31 and salt hydrate (calcium chloride hexahydrate) was used for the simulation study using ANSYS/Fluent. A conjugate heat transfer model employing an enthalpy-based formulation is developed to predict the optimized PCM number of series and optimum airflow rate. Four designs of the AC duct were modelled and evaluated that contained one to four series of PCM containers subjected to different levels of supplied air velocities ranging from 1 m/s–4 m/s. The simulation study revealed that employing four series (Design 4) of PCM enclosures at a low air velocity of 1 m/s enhanced the pre-cooling performance and reduced the outlet air temperature to 33 °C, yielding a temperature drop up to 13 °C. The performance of salt hydrate (calcium chloride hexahydrate) was observed to be better than paraffin (RT-31) in terms of the cooling effect. Characterization of paraffin wax (RT-31) and salt hydrate was performed to establish the thermophysical properties. The experimental setup based on a duct with integrated PCM enclosures was studied. The experiment was repeated for three days as the repeatability test incorporating RT-31 as the PCM and a 3 °C maximum temperature drop was observed. The drop in the outlet air temperature of the duct system quantifies the cooling effect. Net heat reduction was around 16%.

Solar powered hybrid desalination system using a novel evaporative humidification tower: A numerical investigation

This research describes a hybrid solar desalination system that includes a humidification-dehumidification unit as well as a solar still unit. The current system is being studied numerically. A one-dimensional model of the important heat and mass exchanges, as well as the flow field, was built using the finite difference method. Freshwater productivity is calculated under various operating and weather conditions. The model has been modified to investigate the steady-state behavior of the system components. Four major parameters that have a significant impact on system water production are investigated: the feed flow rate of cooling water through the dehumidifier unit, the airflow rate, and the number and height of packing columns. According to the results, the proposed hybrid desalination system provides appropriate operational compatibility between HDH technology and solar energy. The system can provide a daily production of up to 35 liters per day. Increasing the number of packing columns results in a higher increase in fresh water productivity than increasing the height of the packing columns. The optimal air flow rate at a constant saline-water flow rate is obtained. For high airflow rates, the packing column height doesn't significantly affect the daily water production. System performance is investigated by four main parameters: gained output ratio (GOR), humidifier efficiency, exergy efficiency, and system efficiency. The system efficiency reached about 65% and the GOR reached 3.1. The humidifier’s efficiency varied between 50% and 75%. The maximum exergy efficiency reached about 5.2%.

Hydrogen Production Enhancement and Tar Reduction using New Three-Layer Annular Downdraft Air-Steam Biomass Gasifier

This study presents experimental analysis of biomass air-steam gasification for the enhancement of H2 production in producer gas (PG). Wood pellets which are widely available in Malaysia are used in this investigation. A pilot scale downdraft gasifier based on new three-layers annular reactor design was implemented to produce hydrogen enriched PG. The reactor is initially heated using hot flue gas from LPG combustion which is switched to PG when the reactor reaches stable operation. The effect of steam to biomass (S/B) ratio from 1.1 to 1.5 on PG quality in terms of gas composition, HHV and tar contamination is studied. Maximum H2 production of 27.7% was achieved at optimum air flow rate of 75 LPM and S/B ratio of 1.2. At the optimum air flow rate, HHV and tar contamination in PG where in the range of 5.06 - 6.08 MJ/Nm3 and 187 - 30mg/m3, respectively.

Increasing power output and isopropanol biodegradation by trickle-bed microbial fuel cells by optimizing air relative humidity and oxygen flux at cathode

The cathode air flow rate and relative humidity (RH) of a trickle-bed microbial fuel cell (TB-MFC) were optimized using the response surface methodology to obtain a high oxygen flux and a low electrical resistance at the cathode and thereby promote the oxygen reduction reaction. Under optimal air flow rate (2.20 L/min) and RH (20%) conditions, the TB-MFC system exhibited the highest oxygen flux (3.08%/cm2‧min) and the lowest resistance (5.33 Ω); its regression model had an R2 > 0.95 and the desirability coefficient was 0.78. These results demonstrate that the optimized air flow rate and RH support high oxygen flux and low resistance at the cathode. Using biochar combined with conductive carbon black (CCB) as the cathodic catalyst and optimal cathodic operating conditions, yielded a mineralization efficiency of isopropanol of 96.9% and a power density of 555 mW/m3 at an empty bed residence time and isopropanol influx concentration of 60 s and 300 ppmv, respectively. These results suggest that isopropanol can be effectively mineralized directly into CO2 and H2O by a TB-MFC, reducing the by-product accumulation, and thus increasing the power generation of the TB-MFC. Optimizing the air flow rate and RH of the biochar/CCB-based cathode in the TB-MFC increases the oxygen flux and reduces the electrical resistance of the cathode of TB-MFC, which can thus be used to treat exhaust gases that contain organics.

A critical experimental analysis of Humidification-Dehumidification desalination system with mass extraction

The present work reports an experimental investigation of a zero- and single-extraction humidification-dehumidification (HDH) desalination system. While rich thermodynamic modeling of mass extraction/injection-based HDH systems exists in the literature, studies providing design guidelines are lacking. This work aims to elucidate practical design aspects experimentally and report a simple tool for component and system sizing based on the understanding gained from experiments. The effect of the operating parameters such as airflow rates, water flow rates, extraction airflow ratio, top cycle temperature, and salinity on the energy efficiency and yield of the HDH desalination system with and without mass extraction/injection was experimentally examined. It was observed that there is an optimal airflow rate and water flow rate for a zero extraction HDH desalination system at a given top-and-bottom-cycle temperature. The design of mass extraction/injection in advanced HDH cycles involves identifying two key elements of design: (a) location of extraction and (b) amount of airflow extraction/injection. The effect of the airflow extraction location and ratio on the thermal energy efficiency of the single extraction HDH system is reported for different air flow rate conditions. The maximum gained-output ratio for zero- and single-extraction HDH systems was 1.74 and 1.86, respectively. A simple effectiveness-based mathematical model for a single-extraction HDH system is reported that enables component and system sizing.

Comprehensive experimental and theoretical investigations on the effect of microbubble two-phase flow on the performance of direct-contact membrane distillation

This study provides a comprehensive and systematic overview of the application of gas-liquid two-phase flow with microbubbles in the feed stream to improve heat and mass transfer in direct-contact membrane distillation (DCMD) processes for seawater desalination. A swirl-flow-type microbubble generator (MBG) was installed at the feed-side inlet of the DCMD module to investigate its effect on transmembrane flux. The maximum improvement in the MBG-assisted DCMD permeation flux was found to be approximately 18% at a lower feed temperature (40 °C) and optimal air flow rate (50 cc/min), and an optimal MBG geometry comprising a swirler, a nozzle tip of diameter 2 mm, and a diffuser at an angle of 30°. The results were observed to be related to the number density of microbubbles less than 100 µm in size, which plays an important role in improving heat and mass transfer in two-phase flow. In addition, the simulation results based on conventional heat transfer correlations of bubbly flow underestimated the experimental results. Therefore, this study also aims to propose and verify a new two-phase flow heat transfer correlation. The proposed correlation considers the effects of bubble size distribution to accurately predict the performance of MBG-assisted DCMD processes.

Cooling effect of air movement on heating performances of advanced air distribution

The cooling effect of air movement is widely recognized as an energy-efficient measure for thermal environment management under the cooling mode, but it is generally neglected under the heating mode. This study proposes that the cooling effect of air movement negatively impacts the energy efficiency of advanced air distribution and should be considered when modulating advanced air distribution under the heating mode. Advanced air distribution like stratum ventilation and wall attachment ventilation supplies warm and clean air into the occupied zone by employing supply air momentum to suppress thermal buoyancy. However, the supply air momentum elevates the air movement in the occupied zone and the cooling effect of air movement negatively impacts the energy efficiency of advanced air distribution under the heating mode. Based on numerical simulations validated by the experiments, the results show the cooling effect of air movement significantly impacts the optimal operation, particularly the optimal supply airflow rate of stratum ventilation and the optimal supply air temperature of wall attachment ventilation. Accounting for the cooling effect of air movement can improve the optimal overall performance of advanced air distribution, particularly when the preference for energy efficiency increases. Compared with the optimization ignoring the cooling effect of air movement, the optimization considering the cooling effect of air movement improves the overall performance by up to 38.7% for stratum ventilation and up to 67.6% for wall attachment ventilation. Therefore, the cooling effect of air movement should be considered for modulating advanced air distribution under the heating mode.

Characterization of Retronasal Airflow Patterns during Intraoral Fluid Discrimination Using a Low-Cost, Open-Source Biosensing Platform.

Nasal airflow plays a critical role in olfactory processes, and both retronasal and orthonasal olfaction involve sensorimotor processes that facilitate the delivery of volatiles to the olfactory epithelium during odor sampling. Although methods are readily available for monitoring nasal airflow characteristics in laboratory and clinical settings, our understanding of odor sampling behavior would be enhanced by the development of inexpensive wearable technologies. Thus, we developed a method of monitoring nasal air pressure using a lightweight, open-source brain–computer interface (BCI) system and used the system to characterize patterns of retronasal airflow in human participants performing an oral fluid discrimination task. Participants exhibited relatively sustained low-rate retronasal airflow during sampling punctuated by higher-rate pulses often associated with deglutition. Although characteristics of post-deglutitive pulses did not differ across fluid conditions, the cumulative duration, probability, and estimated volume of retronasal airflow were greater during discrimination of perceptually similar solutions. These findings demonstrate the utility of a consumer-grade BCI system in assessing human olfactory behavior. They suggest further that sensorimotor processes regulate retronasal airflow to optimize the delivery of volatiles to the olfactory epithelium and that discrimination of perceptually similar oral fluids may be accomplished by varying the duration of optimal airflow rate.

Quantifying 224Ra/228Th disequilibrium in sediments via a pulsed ionization chamber (PIC)

A new method for measuring 224Ra in sediments is established by use of a pulsed ionization chamber (PIC). Based on the difference in their half-lives, 220Rn can be distinguished from 222Rn so that one can easily measure 224Ra and its parent 228Th in sediment samples. Results show that the measurement efficiency is 0.22 ± 0.02 cpm/dpm, and is not readily affected by moisture. At an optimum airflow rate of 1.2 L/min, the precision of the 224Ra and 228Th measurements is estimated at ±8%. Based on controlled experimental field application and a field application, we show that the 224Ra/228Th disequilibrium in sediments can be assessed and both 224Ra deficits and ingrowth to equilibrium may be quantified. The PIC device is simple to use, inexpensive and portable, making it especially suitable for determinations of sediment samples in the field.

Optimizing the Growth Conditions of the Selected Plant-Growth-Promoting Rhizobacteria Paenibacillus sp. MVY-024 for Industrial Scale Production.

Simple SummaryNitrogen is one of the most important elements for plant growth and development. However, irrational fertilization causes many environmental problems: high rates of nitrogen fertilizers change the soil pH, encourage nitrate and nitrite accumulation in plants and the soil, leached nitrogen compounds cause water eutrophication and drinking water contamination, and gaseous losses of nitrogen contribute to global warming. The biological nitrogen fixation (BNF) process, in which atmospheric nitrogen is converted to ammonia by microorganisms, has a significant role in the global nitrogen cycle and agriculture. Nitrogen-fixing-bacteria inoculants could help to reduce the losses of consistently rising prices of mineral fertilizers and help to implement green revolution strategies. In this research, we found the bacteria strain Paenibacillus sp. MVY-024 that has a positive impact on nitrogen accumulation in spring wheat and was easily applied on an industrial scale.In this study, thirteen isolates, which were possibly expected to fix nitrogen, were isolated from soil and pea root nodules and identified by the gene analysis of 16S rDNA sequences. Two of these isolates that were able to form endospores and grow on nitrogen-free media were selected for spring wheat development research. The isolate Paenibacillus sp. S7 identified as Paenibacillus polymyxa was found to significantly increase the amount of ammonium and mineral N amounts in the soil. Furthermore, increased nitrogen accumulation in grains and a chlorophyll index were obtained after wheat treatment. Paenibacillus sp. S7 isolate was selected for further studies and the accession number MT900581 and strain name MVY-024 in NCBI nucleotide bank for this isolate were assigned. During the cultivation of Paenibacillus sp. MVY-024, sugarcane molasses and a yeast extract were determined as the most suitable carbon and nitrogen sources, whose optimal concentrations were 100 g L−1 and 10 g L−1, respectively. The optimal pH range for the cell culture was between 6.5 and 7.0, and the optimal air flow rate was 0.4 vvm. It was found that the air flow has an effect on biomass production and endospore formation. After Paenibacillus sp. MVY-024 biomass cultivation optimization, the cultured cell number was, on average, 2.2 × 109 cfu m L−1.

Energy Production of Solar DSF for Ceiling-Mounted Localized Air Distribution Systems in a Virtual Classroom

This paper presents an application of energy production in a solar Double Skin Facade (DSF) used in a Heating, Ventilation and Air-Conditioning (HVAC) system for a ceiling-mounted localized air distribution systems in a virtual classroom. In this numerical work, a virtual classroom, an inlet ceiling-mounted localized air distribution system, an exhaust ventilation system, and a DSF system are considered. The numerical simulations consider an integral building thermal response (BTR) and a coupling of an integral human thermal-physiology response (HTR) and differential computational fluid dynamics (CFD). The BTR numerical model calculates, among other parameters, the DSF indoor air temperature and energy production. The HTR numerical model calculates, among other parameters, the human thermal comfort. The CFD numerical model, among other parameters, calculates the indoor air quality. In this study which is performed for winter conditions, the energy produced in the DSF is used for driving the HVAC system. Six different airflow rates are used. The air temperature and energy production in the DSF are also evaluated. The influence of the airflow rate on the HVAC system performance is evaluated by the Air Distribution Index for mid-morning and mid-afternoon conditions. The results show that energy production reduces when the airflow increases and the operating point can be selected using the acceptable levels of thermal comfort and air quality levels or using the maximum Air Distribution Index value. In this study, the application of the thermal comfort and air quality levels criteria demonstrates that the HVAC system uses an optimum airflow rate.

Effect of ventilation mode and airflow rate on the flow field and particle mass concentration distribution of a high-speed rail carriage in the putty polishing workshop

Objectives. The putty polishing procedure usually produces a large number of micron-sized particles, which can lead to serious respiratory diseases as well as skin conditions. The diagonal ventilation system is widely used to decrease the particle concentration in different environments. However, it becomes less effective for a large empty factory workshop, such as the polishing workshop for high-speed rail carriages, in which the diagonal ventilation mode usually results in turbulence in the airflow. In this article we report that the situation can be improved by optimizing the number and locations of the air inlets and outlets in the carriage-polishing workshop. Three modified ventilation modes are proposed, whose efficiencies are evaluated by numerical simulations and compared to the diagonal mode. Results. The results show that the mode with two inlets close to the ceiling and two outlets close to the floor yields the best performance. Besides, the optimum airflow rate under this mode is further determined by both simulations and in-situ measurements. The results reported can serve as a reference for the design of the ventilation systems in the polishing workshops of similar sizes.

Experimental and simulation performance optimization of an exhaust air heat recovery heat pump unit

Abstract In order to optimize the performance of exhaust air heat recovery heat pump unit (EAHRHPU), Simulink system simulation and Simulink-M file optimization model were established in this paper to study the performance of the unit in variable outdoor air conditions by combining experiment. Finally, the optimal performance of coefficient and the corresponding optimal bypass fresh air flow rate of the unit in different outdoor temperature was obtained. The results showed that the change trend of the simulation value and the test value of the unit’s performance parameters is consistent, and the maximum deviation is controlled within ±7.00% in the standard cooling condition and variable bypass fresh air. The simulation model can correctly reflect the performance changes of the unit during the operation. The operation performance of the unit was affected by the temperature and air flow rate of the bypass fresh air in variable outdoor conditions. The Simulink-M file optimization model can obtain the specific value of the optimal bypass air flow rate in different outdoor temperatures. As the outdoor temperature increases, the optimal bypass fresh air flow rate increases first and then decreases. With the use of variable frequency fans, the unit can achieve better energy utility effect. The research could be considered as the useful reference for improving the operation performance of the EAHRHPU.

The effect of fan setting, air-conveyor orientation and nozzle configuration on airblast sprayer efficiency: Insights relevant to trellised vineyards

A step-by-step laboratory procedure was used to identify the optimal configuration of a tower-shaped trailed sprayer intended for application in vertical shoot trellised vineyards. Different fan settings, air-conveyor orientation, and nozzle configuration were tested for their effect on both airflow pattern and vertical spray distribution. The optimal airflow rate at the fan outlet and the airflow velocity pattern at crop target distance were identified for different fan settings obtained by the combination of two fan gear speeds and three Power Take Off speeds (450, 500 and 540 rev min−1). The difference in the airflow pattern between factory air deflector settings and the adjusted ones was tested. Once the optimal fan setting was selected, the use of 12 or 16 active nozzles and 4 nozzle types was also tested. The optimal vertical spray profiles were determined based on defined thresholds of i) coefficient of variation, ii) amount of spray liquid lost above the target height and iii) two symmetry indices. The low fan gear speed combined with PTO set at 450 rev min−1 result in the best option to reduce and obtain adequate air velocities. The adjustment of deflectors allowed to exactly match the spray to the canopy target height. Concurrently, the use of 12 nozzles drastically reduced the spray losses above the target height. Finally, 4 configurations out of 18, featured by the combination of a different nozzle type and number of active nozzles, met all the criteria set for optimal vertical spray profile.