Air Blower Research Articles

Use of Liquid Culture with the ElecTIS Bioreactor for Faster Recovery of Blackberry (Rubus fruticosus L.) Shoots from Conservation at 4 °C

ElecTIS is a new single container bioreactor which does not require forced air blowing, instead making the culture material mobile and the liquid medium stationary. The timed up-and-down movement of the basket containing the shoot culture ensures periodic contact with the liquid medium positioned at the base of the container. In this study we tested for the first time its use in the recovery of blackberry shoot cultures (Rubus fruticosus L., cvs Thornfree and Chester), coming from 5 months of slow growth storage (SGS), at 4 °C and in the dark. The shoot recovery at standard culture conditions was performed on two different types of ElecTIS, i.e., one with a smaller basket (ElecTISS, 234 cm2 of culture area), and one with a large basket (ElecTISL, 336 cm2), comparing the culture in TIS (cycle of 8 min every 6 h, equal to 32 min/day) with the traditional one in a gelled medium in glass jars (500 cc). After each one of the three 4-week subcultures, the shoot growth parameters and the relative growth rate highlighted a clear superiority of ElecTIS in promoting the recovery of shoot cultures coming from SGS. The analyses of chlorophyll content and stoma functionality confirmed the superior quality of shoots cultured in the ElecTIS bioreactor, and these shoots were afterwards easily rooted and acclimatized ex vitro.

Aerodynamic noise reduction of a blunt flat plate by trailing-edge blowing

This study investigates the influence of air blowing on the aerodynamic noise generated by a flat plate with a blunt trailing edge. The uniform blowing was applied through evenly spaced holes along the span at the base of the flat plate. Acoustic pressure measurements were conducted in an anechoic wind tunnel using a free-field microphone at Reynolds numbers ranging from 2.8×105 to 6.5×105. Particle image velocimetry measurements were performed to obtain time-resolved evolution and statistics of the flow velocity field, providing a detailed understanding of the noise reduction mechanisms. The results demonstrated that air blowing effectively reduces both the amplitude and bandwidth of tonal and broadband noise within a limited frequency range. This phenomenon was attributed to the stabilization of separated shear layers over a longer distance by air blowing and a decrease in turbulent kinetic energy in the near-wake region. It was shown that air blowing suppresses the tonal peak of vertical velocity fluctuations and narrows the wake width, which accounts for the increase of vortex shedding frequency and a potential drag reduction. Generally, the effects of air blowing on vortex shedding at the blunt trailing edge are analogous to those of a splitter plate. The unaffected convective velocity of the large-scale vortex structures and the enhanced spanwise coherence in the vortex formation region provide further evidence to this analogy.

Bus Cabin Noise Predictions of Large HVAC System using Total Noise Method

HVAC system design has an accountability towards acoustic comfort of passengers of a vehicle. Owing to larger cabin volume of a bus, multiple air blowers have to be installed to ensure comfort of passengers. Such multiple blowers produce significant flow induced noise inside the cabin. For commercial success, it becomes essential to predict intensity of such a flow induced noise at very early stages in product development. Conventionally sliding mesh based CFD approach is deployed to predict flow and turbulence noise around each blower. However due to complexity, this method becomes computationally intensive resulting in cost and time inefficiency. Hence it is desirable to innovate around an alternative rapid, reliable prediction method, which ensures quick turnaround of prediction. This paper describes a unique innovative approach developed around a multiscale method where flow induced noise generated by a single blower in motion is predicted using commercial Lattice Boltzmann CFD software with a digitally scaled down HVAC system in an anechoic digital wind tunnel. These CFD predictions are used to replace all blowers with virtual stationary speakers inside digital cabin to emulate noise emanated by a large HVAC unit. Authors named this method as total Noise Multiscale Approach, in the paper. With the total multiscale approach, overall sound pressure level predicted inside the bus cabin at rear passenger ear levels are comparable with the physical test measurements and has shown fair correlation. Using this multiscale total noise method, computational cost and turnaround time has significantly reduced compared to the flow conventional resolving approach for cabin with all the blowers. This predictive total noise method found useful in designing and planning countermeasures during product development.

Sistem Backwash Pada Filtrasi Sistem Pengolahan Air Minum Menggunakan Motor Listrik Pompa Sentrifugal di Perusahaan Umum Daerah Air Minum Tirta Madani Kota Serang

The need for water consumption is currently very high, almost all human activities require water, therefore the process and production of water is very important to maintain health, the electric motor is the main driving tool needed in the process of cleaning water, therefore the motor is able to move the machine to clean the place water filter or water filter at the Tirta Madani Regional Drinking Water Company in Serang City to maintain water quality. The method used is qualitative by using observation techniques, interviews and literature studies. The filter backwash system is one of the ways to care and maintain the quality of drinking water. Backwashing requires an electric motor, a centrifugal pump and an air blower as its propulsion device.

Effect of air blowing inside isolated hospital clothing on perceptual and physiological heat strain in laboratory conditions.

Heat stress is one of the most common complaints of health care employees who wear isolation gowns to protect themselves from biological agents, particularly during the warmer seasons. This study was conducted in a climatic chamber to determine the influence of airflow within isolated hospital gowns on physiological-perceptual heat strain indices. The experiment was conducted in three trials: regular clothes (CON), an impenetrable gown without air blowing (GO), and a gown with air blowing (GO + FAN) at temperature conditions of 27°C and 25% relative humidity (RH). During the trial, physiological-perceptual response data were recorded for a half-hour on a treadmill at a speed of km/hr and a slope of 0% activity at 5-min intervals. The ASHRAE Likert scale was used to assess thermal comfort (TC), thermal sensation (TS), and skin wetness sensation (WS). As the results show, there was a significant difference in mean scores for TC and WS in both sexes when working in the CON, GO, and GO + FAN groups (P < 0.001). In women, the mean scores for TS, TC, and WS reduced considerably (P < 0.001) in the GO and GO + FAN in the amount of 10 and 12 CFM (20 [Formula: see text]/h), but in males, there was a statistically significant difference between mean scores (P < 0.001) in the GO + FAN at 12 CFM (20 [Formula: see text]/h) and 14 CFM (24 [Formula: see text]/h). Also, the greatest difference between the average heart rate, chest temperature, and temperature inside the clothes in women and men in the trials GO and GO + FAN was observed in the air flow 12 CFM and 14 CFM, respectively (P < 0.001). The usage of an air blower in isolated hospital clothes has been shown to influence physiological-perceptual parameters in men and women substantially. The existence of airflow in these gowns can improve safety, performance, and thermal comfort while also decreasing the risk of heat-related disorders.

Thermo-Electro-Fluidic Simulation Study of Impact of Blower Motor Heat on Performance of Peltier Cooler for Protective Clothing

The necessity for portable cooling devices to prevent thermal-related diseases in workers wearing protective clothing in hot outdoor weather conditions, such as COVID-19 quarantine sites, is increasing. Coolers for such purposes require a compact design and low-power consumption characteristics to maximize wearability and operating time. Therefore, a thermoelectric device based on the Peltier effect has been widely used rather than a relatively bulky system based on a refrigeration cycle accompanying the phase change of a refrigerant. Despite a number of previous experimental and numerical studies on the Peltier cooling device, there remains much research to be conducted on the effect and removal of motor-related internal heat sources deteriorating the cooling performance. Specifically, this paper presents thermo-electro-fluidic simulations on the impact of heat from an air blower on the coefficient of performance of a Peltier cooler. In addition, a numerical study on the outcome of heat source removal is also evaluated and discussed to draw an improved design of the cooler in terms of cooling capacity and coefficient of performance. The simulation results predicted that the coefficient of performance could be raised by 10.6% due to the suppression of heat generation from a blower motor. Accordingly, the cooling capacity of the specific Peltier cooler investigated in this study was expected to be considerably improved by 80.6% from 4.68 W to 8.45 W through the design change.

Cryogenic CO2 assisted hard turning of AISI 52100 with robust CO2 delivery

Cryogenic-assisted hard turning arises a promising sustainable manufacturing technology, emerging as an interesting alternative to conventional grinding. The replacement of traditional metalworking fluids for cryogenic CO2 cooling presents significant environmental benefits as well as the potential process performance improvement. In this paper, a novel cryogenic CO2 delivery system which enables CO2 mass flow and phase control is introduced. In this way, more stable and localized cooling of the cutting zone is obtained in comparison to direct connection delivery systems reported in literature. Finally, this system is employed to perform hard turning tests of hardened bearing steel 52100, where tool wear and surface integrity results are compared to dry air blow and conventional cooling conditions. The application of the cryogenic cooling was found to improve conventional cooling and dry cutting conditions for semi-finishing operations at elevated cutting speeds.

Parametric optimization and experimental verification of multi-fertilizer mixing by air blowing and blade stirring based on discrete element simulations

In proportional variable-rate fertilization, improving the uniformity of multi-fertilizer mixing helps to improve the overall utilization efficiency of fertilizers. In this paper, a multi-fertilizer mixing by air blowing and blade stirring was presented. Using fertilizer granules mixing uniformity as an indicator, the method optimized the structures and working parameters of single-blade group stirring, double-blade group stirring and air blowing & double-blade stirring. EDEM and Fluent software were used for the simulation and the results were verified by experiments. The simulation results showed that the appropriate speed range of single-blade group stirring was 600 ∼ 900 r⋅min−1 and the highest mixing uniformity was achieved with the blade mounting angle α of 20°. The best structure of double-blade group stirring was achieved with an upper blade mounting angle β of 20°, a lower blade mounting angle θ of −20° and a spacing h of 89 mm. For the air blowing & double-blade stirring method, the best results were achieved when the input air velocity va was 8.4 m⋅s−1 and the blade speed of agitator nb was 740 r⋅min−1. The mixing uniformity of nitrogen (N), phosphate (P) and potash (K) fertilizer granules reached 98.41%, 98.12% and 98.31%, respectively. The bench test results showed that the mixing uniformity by air blowing & double-blade stirring was better than that by double-blade group, and the mixing uniformity by double-blade group was better than that by single-bladed group, which were consistent with the simulation results. Meanwhile the differences between experimental values and simulation values were within 2%, which showed that the simulation models were reliable. Results from this study can be used as reference for the design of mixing devices of variable-rate fertilization.

Designing and Simulation Assessment of a Chair Attachment Air Blowing Methods to Enhance the Safety of Prolonged Sitting.

Musculoskeletal disorders and the stagnation of sitting are among the side effects of excessive sitting in awkward sitting positions. In this study, a developed chair attachment cushion design with an optimal air blowing technique is proposed to eliminate the negative side effects of prolonged sitting. Instantaneously reducing the contact area between the chair and its occupant is the fundamental goal of the proposed design. The fuzzy multi-criteria decision-making approaches represented by FAHP and FTOPSIS were integrated to evaluate and select the optimal proposed design. An ergonomic and biomechanics assessment of the occupant's seating position while employing the novel safety cushion design was validated using simulation software (CATIA). Sensitivity analysis was also used to confirm the design's robustness. Results show that the manual blowing system using an accordion blower was the optimal design concept based on the selected evaluation criteria. In fact, the proposed design provides an acceptable RULA index value for the examined sitting postures and performed very safely in the biomechanics single action analysis.

Flexible and Slim Device Switching Air Blowing and Suction by a Single Airflow Control

This study proposes a soft robotic device with a slim and flexible body that switches between air blowing and suction with a single airflow control. Suction is achieved by jet flow entraining surrounding air, and blowing is achieved by blocking and reversing jet flow. The thin and flexible flap gate enables the switching. Air flow is blocked while the gate is closed and passes through while the gate is open. The opening and closing of the flap gate are controlled by the expansion of the inflatable chambers installed near the gate. The extent of expansion is determined by the upstream static pressure. Therefore, the gate can be controlled by the input airflow rate. The dimensions of the flap gate are introduced as a design parameter, and we show that the parameter contributes to the blowing and suction capacities. We also experimentally demonstrate that the proposed device is available for a variable friction system and an end effector for picking up a thin object covered with dust.

Analysis of the Performance of Liquid Fertilization in Cucumber Cultivation

Liquid fertilization can be applied to cucumber plants, including using electric sprayers, electric sprayers and air blowers, and using the mist blower. The three sprayer units are capable of producing fine granules (droplets) that can enter the stomata of cucumbers. This study aims to compare the results of spraying performance using the three methods of liquid fertilization in cucumber cultivation. The research method used is indoor testing in the Sprayer Laboratory to determine the value of the performance parameters of each method of liquid fertilization and outdoor testing to apply liquid fertilizer droplets to cucumbers and determine their effect on the growth and production of cucumbers. The results showed that the first fastest appearance of the flower and the first fruit was in the treatment using electric sprayers and air blowers at 24.6 days after planting (DAP) and 31.5 DAP. This treatment also produces cucumbers with the largest diameter, length, and weight of the fruit of 2.97 cm, 26.10 cm, and 298.28 grams. The accuracy of the dose of liquid fertilization application using an electric sprayer and air blower is 63.41%, an electric sprayer of 59.56%, and the mist blower of 29.90%. Keywords: Air blower, Droplet, Electric sprayer, Mist blower, Sprayer

A Numerical Study on the Flap Side-Edge Noise Reduction Using Passive Blowing Air Concept

The flap side-edge is a vital contributor to airframe noise. In this study, we propose a novel flap side-edge noise reduction method based on the concept of active blowing air. A long slot is opened from the flap’s lower surface to the tip surface to induce a secondary jet flow, which is driven by the local pressure difference between the flap’s lower surface and the tip surface. The unsteady flow field around the flap side-edge was computed by the lattice Boltzmann solver PowerFLOW, and the far-field noise was predicted by the FW-H equation. It is demonstrated that the dominant features of the flap side-edge flow are the double vortex structures, and the new passive blowing air reduction method can achieve about 3.3 dB noise reduction. Moreover, the underlying noise reduction mechanism has been analyzed and revealed. It is shown that the secondary jet flow from the long slot on the flap side-edge would dissipate the flap side-edge vortex and displace the flap side-edge vortical structure away from the flap surface, thus resulting in a decrease in the pressure fluctuations on the flap side-edge surface. As a result, the flap side-edge noise was reduced. In contrast to the current active air blowing technique, the newly proposed blowing air technique is passive and quite simple and does not require an extra air source or control system. This novel flap side-edge noise reduction technology provides a new flow control strategy and noise reduction methodology and can be further optimized.

Magnesiation roasting kinetics exploration of vanadium slag toward minimization of tailing toxicity

In order to minimize the toxicity of vanadium extraction tailings, the vanadium extraction efficiency should be as high as possible to minimize the residual V(V) content in tailings. In this work, the kinetics of the novel magnesiation roasting of vanadium slag, including the roasting mechanism and kinetic models, is explored to intensify the vanadium extraction. By combination of various characterizations, the microscopic mechanism of magnesiation roasting is revealed, which indicates the simultaneous occurrence of the salt-formation→oxidation routine (major) and the oxidation→salt-formation routine (minor). Macroscopic kinetic model studies show the magnesiation roasting of vanadium slag proceeds in two stages. In the initial 50 min, the roasting follows the Interface Controlled Reaction Model, during which the stable roasting temperature is essential to intensify the magnesiation. In the long-time range (50–90 min), the roasting follows the Ginstling-Brounstein Model, during which the acceleration of air blow rate is most favorable. With intensified roasting kinetics, the vanadium extraction efficiency is as high as 96.65%. This work has provided the guideline to intensify the magnesiation roasting of vanadium slag for vanadium extraction, which can not only minimize the tailing toxicity of vanadium extraction but also accelerate the industrial application of the novel magnesiation roasting technique.

CO2 capture and sequestration from a mixture of direct air and industrial exhaust gases using MDEA/PZ: Optimal design by process integration with organic rankine cycle

Achieving climate change targets requires a massive reduction in carbon dioxide emissions. According to the Paris agreement, this amount should be reached to 30 Gt/year CO2 reduction. Among different energy and environmental technologies, CO2 Capture and Storage (CCS) technologies are promising technologies to achieve those goals. Despite different technical, economical, and environmental CCS challenges, process development based on recent advances can significantly facilitate the CCS’s deployment. This study aims to simulate the absorption system of CO2 with Methyl-Diethanolamine (MDEA) and Piperazine (PZ) absorbents. In this study, three different scenarios have been considered for designing the parts of the absorption tower and air blower that have the highest energy consumption to achieve the highest amount of absorption, purity, and CO2 recovery. Compared results from the defined scenarios show that the use of an intercooler in the middle of the adsorption tower (Scenario 3) is the best design for the CO2 capture simulated process where the adsorption rate is 90.1%, the purity is 82.26 (mol%) and CO2 Recovered reaches 28.74 ton/hr. Since energy consumption in high CO2 absorption rate and purity is one of the main challenges of such technologies, this study also evaluates the combination of the organic Rankin cycle (ORC) with air blowers by three refrigerants R290, R227, and R124 to reduce energy in the carbon capture units. The results show that in this cycle, R290 has the highest power output against R227 and R124 refrigerants under the same conditions. Combining ORC with an air blower reduces the cooling load of the whole process to 104.85 MW and the total power consumption to 46.375 MW. Finally, this study concludes that using different designs and combinations, including ORC cycles in high-energy CCS processes, can also reduce the cost of energy required, and its deployment can help prevent climate change.

Soft Electromagnetic Motor and Soft Magnetic Sensors for Synchronous Rotary Motion.

To create fully-soft robots, fully-soft actuators are needed. Currently, soft rotary actuator topologies described in the literature exhibit low rotational speeds, which limit their applicability. In this work, we describe a novel, fully-soft synchronous rotary electromagnetic actuator and soft magnetic contact switch sensor concept. In this study, the actuator is constructed using gallium indium liquid metal conductors, compliant permanent magnetic composites, carbon black powders, and flexible polymers. The actuator also operates using low voltages (<20 V, ≤10 A), has a bandwidth of 10 Hz, a stall torque of 2.5-3 mN·m, and no-load speed of up to 4000 rpm. These values show that the actuator rotates at over two orders-of-magnitude higher speed with at least one order-of-magnitude higher output power than previously developed soft rotary actuators. This unique soft rotary motor is operated in a manner similar to traditional hard motors, but is also able to stretch and deform to enable new soft robot functions. To demonstrate fully-soft actuator application concepts, the motor is incorporated into a fully-soft air blower, fully-soft underwater propulsion system, fully-soft water pump, and squeeze-based sensor for a fully-soft fan. Hybrid hard and soft applications were also tested, including a geared robotic car, pneumatic actuator, and hydraulic pump. Overall, this work demonstrates how the fully-soft rotary electromagnetic actuator can bridge the gap between the capabilities of traditional hard motors and novel soft actuator concepts.

Enhanced Aircraft Wake Decay Under Crosswind Conditions

The starting vortex generated by air blowing from the ground destroys the aircraft wake vortex within a short period of time. Thus, air blowing might shorten flight separation and promote airport operating efficiency. A crosswind is a common phenomenon affecting airplane landing, and it can greatly affect air blowing. In this paper, a large-eddy simulation was used to study the interference exerted by different blowing zones on a wake vortex. The best-performing blowing strategy was estimated by ascertaining the relationship between the blowing zone aspect ratio and the corresponding starting vortex strength. It was found that, without the crosswind, the blowing effect remained almost constant for an aspect ratio of between one and 16. A passive tracer released from the different blowing zones proved that the mechanisms of enhanced vortex decay, with or without crosswind, were identical. However, the results showed that crosswind caused asymmetrical and reduced artificial wake decay enhancement. When the crosswind was imposed, the development of the upwind vortex was sensitive to the aspect ratio, and the blowing zone with an aspect ratio of 16 showed the best performance.

Fast and Visual Detection of Biogenic Amines and Food Freshness Based on ICT‐Induced Ratiometric Fluorescent Probes

AbstractBiogenic amines (BAs) are important indicators for the evaluation of food spoilage and disease diagnosis. Thus, the detection of BAs with high practical potential is of great importance. In this work, a new BAs fluorescent probe design strategy is proposed by the intramolecular charge transfer (ICT) enhancement of the fluorescent probes, which is induced by the hydrogen bond interaction between probes and analyte. The probes T1 and T2 with donor–acceptor structure not only present a 140 nm bathochromic‐shifted emission, ultrafast responses (15 s for T1 and 25 s for T2), and high sensitivity (detection limit of 1.3 ppm for T1 and 2.6 ppm for T2) to cadaverine (the typical representative of BAs) but also discriminate a series of BAs and simply reused at least 30 times after air blowing. Further, a quantitative evaluation system is obtained based on T1 and T2 films. Through the Red/Green/Blue analysis with a smartphone, the total volatile basic nitrogen (an international standard to assess food spoilage) value can be output to quantitatively evaluate the freshness of food. The system is fast, visual, accurate, and non‐destructive, enabling consumers and all stakeholders in the food supply chain to monitor food freshness.

Sorting of Fresh Tea Leaf Using Deep Learning and Air Blowing

The sorting of machine-picked fresh tea leaves after mechanized harvesting remains a challenge because of the complex morphological characteristics and physicochemical properties of fresh tea leaves. First, the recognition results of four types of models, namely, YOLOv5, YOLOv3, Fast RCNN, and SSD, were compared. It was found that YOLOv5, with guaranteed recognition accuracy, had a recognition speed of 4.7 ms/frame (about four times that of the second ranked YOLOv3). Therefore, this study presents a novel fresh tea leaf sorting system that provides rapid and high-precision multi-channel sorting for four grades of tea leaves using a tea leaf recognition model based on the You Only Look Once (YOLOv5) deep learning model. Subsequently, a raw dataset, consisting of 6400 target images of different grades and different moisture contents, was used to evaluate three different optimization methods. Among these, the Stochastic Gradient Descent (SGD) optimization method was found to provide the best model training results with an average recognition accuracy of 98.2%. In addition, the recognition efficacy of the recognition model was found to be positively correlated with the gradient coverage of tea’s moisture content in the training set. Theoretical analysis was then conducted, along with the experimental investigation of the air-blowing force on the fresh tea leaves in the sorting process, with 30° determined to be the optimal air-blowing angle. Finally, the overall results showed that the construction of the full moisture content training set enabled a model recognition accuracy of up to 88.8%, a recall of 88.4%, a recognition speed of 4.7 ms/frame, and an overall sorting accuracy of 85.4%. This result is promising for multi-channel sorting of fresh tea leaf grades in complex situations, and as such provides a strong basis for the application of tea leaf sorting equipment.

Dynamic acoustoelastic testing (DAET) with a thermal strain pump for characterization of closed fatigue cracks

Dynamic acoustoelastic testing (DAET) is a nonlinear acoustic technique used to characterize the nonlinear elastic behavior of materials. To enable the in-situ implementation of DAET, we propose a modification to the conventional DAET setup by replacing the mechanical strain pump with a thermal strain pump. This study presents the feasibility of the proposed thermal-pump DAET setup for in-situ detection of closed fatigue cracks in an aluminum test specimen. Our setup employs a hot air blower to induce a small (∼4 °C) thermal gradient near the surface of the specimen. The surface temperature evolution is captured by an infrared camera allowing thermal strain evaluation on the surface. A pair of high frequency angle-beam Rayleigh surface wave transducers are used to probe the thermal strain-induced changes in near-surface elastic properties. The slope of the relative change in Rayleigh wave speed with the applied thermal strain is taken as a measure of nonlinearity (γ) evaluated at several locations across the specimen along the intact and cracked regions. Our results show that γ measures higher near the crack and decreases as the probe moves towards the crack tip, demonstrating the potential of thermal-pump DAET for in-situ evaluation of closed fatigue cracks.

Thermo-Statistical Investigation of the Solar Air Collector Using Least Angle Regression

The paper presents the notion of high dimensionality—in the results—that could change the exergy and energy characteristics of the two-pass solar collector. To examine the energetic aspect of the collector, two different types of absorber plate surfaces were chosen: one that is smooth and one with triangular fins. Both designs have two-pass and wooden baffles underneath their absorber plates. The induced air blower was used for the forced convection of air. To examine the attribute of the data, the least angle regression (LARS) algorithm was used to find a new exergy model without overfitting the data. The second law efficiency dropped by 18.92% for the given models of the solar collector when the air flow rate surged further from 10.10 g·s−1 to 12.10 g·s−1, whereas the energy efficiency showed contradictory behaviour for the given range of air flow rate. It increased by 3% in the first half of the rise in the air flow rate, and on the other hand, a jump of 8% was recorded in the energy efficiency with a rise in the air flow rate by 19.80%. The addition of wooden baffles in the second passage of the flat plate two-pass collector increased the entropy generation due to air friction by 200%, albeit it dropped by 50% at 12.10 g·s−1. Upon increasing the air stream rate from 8.10 g·s−1 to 12.10 g·s−1, the exergy destruction rate at the front finned surface of the two-pass solar air collector receded by 5.49–8.76%, and at the same time, it elevated for the rear passage provided with the wooden baffles. However, it decreased for both the front and rear surfaces of the solar air collector, as the air flow rate increased by 24.69%.