Blower Type Research Articles

Combine Effect of Blade Type of Blower and Speed of Operation on Droplet Size in Air Assisted Orchard Sprayer

Droplet size analysis of orchard sprayer having axial flow blower was carried out to determine the changes in droplet size at different blade types and speed of operation. Droplet size analysis was carried out at two different positions (Outer and Inner) of crop canopy and at three different heights (Top, Middle, Bottom) of each crop canopy. On outer canopy, at top position, at speed of operation 2.5 km/h, 3.0 km/h and 3.5 km/h the droplet size decreased by 6.5 %, 7.6 % and 10.3 % respectively when the blade was changes from blade type 1 to blade type 2. When the blade was changes from blade type 1 to blade type 2 in combination of speed of operation 2.5 km/h, 3 km/h and 3.5 km/h the droplet size decreased by 6.2 %, 7.3 % and 8.6 % and 5.4 %, 6.8 % and 9.0 % for middle and bottom position. On inner canopy, at top position, when the blade type was changes from blade type 1 to blade type 2 at speed of operation 2.5 km/h, 3.0 km/h, 3.5 km/h, then the droplet size decreased by 7.3 %, 9.2 % and 10.2 % respectively. Whereas at middle position the droplet size decreased by 7.1 %, 7.6 % and 9.0 % respectively. Similar trend was observed in bottom position and decrease in values of droplet size was 5.6 %, 7.1 % and 8.9 % observed respectively. Keywords: Droplet Size, orchard sprayer, axial flow blower, crop canopy.

Effect of Geometric Differences Impeller Blades on Performance Blower as Turbine (BAT) on Pico-Hydro Scale

The classification of centrifugal blowers is determined by the geometry of the angle when water leaves the outer side of the impeller blade (?), namely ? > 90 0 , ? = 90 0 , and ? 90 0 has characteristics which is relatively the same as the francis turbine impeller blades, but the blower type ? > 90 0 is rarely sold in the market, which is widely sold in the market is the blower with angle ? 90 0 . The aim of this study was to analyze the performance of BAT ? = 90 0 and BAT ? > 90 0 and compare them with the original BAT (? 90 0 produced better efficiency compared to the straight blade BAT (BAT ? = 90 0 ) and the original blade BAT (BAT ? 90 0 is more responsive in generating power

Mist blower performance for liquid fertilizing on eggplant vertical culture cultivation system

The objective of the research was to test the performance of two types of knapsack mist blowers for liquid fertilizing on eggplant vertical culture cultivation system. The research was conducted from March to June 2019 at the Sprayer Laboratory, Leuwikopo, Bogor, West Java, Indonesia, to determine parameters of droplet diameter, droplet density, effective spraying width, and effective spraying debit. The research was also conducted on the field of Siswadhi Soepardjo Field Laboratory, Leuwikopo, to determine the harvested weight of eggplants. Spraying tools and material were knapsack mist blower type A (Shandong 3WF-3), knapsack mist blower type B (Tasco MD-160), and liquid fertilizer. Results of the research showed that mist blower type A had less wind speed and more nozzle vanes number than mist blower type B so that it influenced their liquid fertilizing performances. Mist blower type A produced smaller or finer droplet diameter, larger droplet density, and smaller effective spraying debit than mist blower type B, whereas mist blower type B produced larger effective spraying width than mist blower type A. Mist blower type A and type B produced droplet diameter, droplet density, effective spraying width, and effective spraying debit were 301.51 micronmeter, 64.63 droplet cm−2, 64 cm, and 2.37 liter min−1, and 331.12 micrometer, 181.28 droplet cm−2, 72 cm, and 3 liter min−1 in average respectively. Mist blower type A has produced maximum harvested eggplants weight of 96.22 g/fruit on average on the optimum walking speed of 0.92 m/s with 2 liter ha−1 liquid fertilizer dosage. Mist blower type B has produced maximum harvested eggplants weight of 61.66 g/fruit on average on the optimum walking speed of 1 m s−1 with 2 liter ha−1 liquid fertilizer dosage.

Hydraulically Powered Wood Chip Blower in Test and Its Use Opportunity in Biofuel Supply Chain

Most forest chips are delivered to large-sized, combined heat and power plants in Finland. In this study, we introduce and demonstrate the small-scale delivery of forest wood chips to potential clients, with the wood chips being delivered in a container truck and pneumatically blown into a storage facility. This arrangement of wood chips being blown through a pipe into a storage eliminates the ground handling while requiring a relatively small space. In the demonstration tests, we tested the volumetric flow of biomass in the hose and its noise level while the blower was blowing the material and the flow speed of the material in the hose. This study discusses the test conditions in which the compatibility and suitability of the truck and its hydraulic system were used in conventional chip delivery in Finland and the selected blower type was investigated. According to the results, the biomass volume flow was higher (~0.46 m3/min) when the blower revolution was lower (2392 - 2566 RPM). However, when the RPM was increased to ~3000, the volumetric flow decreased to ~0.24 m3/min. Similarly, the speed of the chips was higher with a lower RPM; 29.9 m/s at an RPM of 2400 and 25 m/s at an RPM of 2700. This is potentially due to both the blower and screw conveyer using the same power source. Additional optimization research would be needed to conclusively state the root cause of this phenomenon. On the other hand, chips from pruned stems had better flow than the chips from whole trees, since chips from whole tree have a wider range of chips sizes, including 1.3% of chips being in the range of 31.5 - 40 mm. The larger chips clogged the hose, which hindered the flow. Finally, the noise tests showed that it was louder at 0 degrees, which contrasted with the situation for the blower, with an aside at 90 degrees.

Stability of Non-Axisymmetric Rotor and Bearing Systems Modeled With Three-Dimensional-Solid Finite Elements

Abstract Although rotors are simplified to be axisymmetric in rotordynamic models, many rotors in the industry are actually non-axisymmetric. Several authors have proposed methods using 3D finite element, rotordynamic models, but more efficient approaches for handling a large number of degrees-of-freedom (DOF) are needed. This task becomes particularly acute when considering parametric excitation that results from asymmetry in the rotating frame. This paper presents an efficient rotordynamic stability approach for non-axisymmetric rotor-bearing systems with complex shapes using three-dimensional solid finite elements. The 10-node quadratic tetrahedron element is used for the finite element formulation of the rotor. A rotor-bearing system, matrix differential equation is derived in the rotor-fixed coordinate system. The system matrices are reduced by using Guyan reduction. The current study utilizes the Floquet theory to determine the stability of solutions for parametrically excited rotor-bearing systems. Computational efficiency is improved by discretization and parallelization, taking advantage of the discretized monodromy matrix of Hsu's method. The method is verified by an analytical model with the Routh–Hurwitz stability criteria, and by direct time-transient, numerical integration for large order models. The proposed and Hill's methods are compared with respect to accuracy and computational efficiency, and the results indicate the limitations of Hill's method when applied to 3D solid rotor-bearing systems. A parametric investigation is performed for an asymmetric Root's blower type shaft, varying bearing asymmetry and bearing damping.

Modeling the energy and cost impacts of excess static pressure in central forced-air heating and air-conditioning systems in single-family residences in the U.S.

Many central residential forced-air heating and air-conditioning systems contain high pressure drop elements such as high-efficiency or dust-loaded filters, dirty coils, or constricted or undersized ductwork, which are widely assumed to have substantial energy and economic impacts. However, the overall energy and cost consequences of excess static pressures have not been explored in depth across a wide range of climates, homes, or system characteristics. Therefore, we performed 780 annual building energy simulations using BEopt and EnergyPlus to predict the energy and cost impacts of realistic excess static pressures for typical new and existing single-family homes with both permanent split capacitor (PSC) blowers and electronically commutated motors (ECM) in 15 U.S. climate zones. Results demonstrate that excess static pressures can increase annual energy consumption and costs, but the magnitude varies by blower type and climate zone. Moderate increases in static pressures (i.e., from 50 to 150Pa) were predicted to yield minimal increases in annual space conditioning energy costs (i.e., less than 3% across all homes, blowers, and climates), while more extreme increases in static pressure (i.e., from 50 to 350Pa) were predicted to yield average increases in energy costs of ∼9% with ECM blowers and ∼18% with PSC blowers.

Volumetric resistance blower

This paper reports on a new low-noise blower rotor technology developed by Intel Corporation (patents pending). The new approach replaces the traditional centrifugal blower rotor with a block of continuous porous media. The porous media can be as simple as a low-cost, block of open-cell foam and has no blades or macroscale structure. As the porous media rotor rotates, viscous and inertial forces from the volumetric resistance of the porous media cause the air within the rotor to rotate with it, creating centrifugal forces that overwhelm the flow resistance in the radial direction and create a flow pattern similar to that achieved in a traditional blower. However, because of the lack of distinct blades, the porous-media generates nearly zero aerodynamic tonal noise and significantly reduced broadband noise. This allows the rotor to be operated at significantly higher RPM and reduced clearances relative to the traditional rotor design for further improved performance. This paper will discuss numerical modeling and experimental development of the new blower type. An iso-flow comparison of porous-media and traditional rotors with the same motor and housing demonstrate a 5 dBA reduction in broadband noise and a factor of two reduction in tonality while maintaining comparable overall efficiency. Impact of porosity and different rotor support structures are also discussed.

Wall pressure sources near an airfoil trailing edge under turbulent boundary layers

In the present work the wall pressure sources under turbulent boundary layers developing on the surface of an airfoil have been investigated in the region near the trailing edge. A trip wire placed on the surface of the airfoil close to the leading edge ensured a turbulent boundary layer for the two Reynolds numbers investigated. When the angle of attack was different than zero, for the lower Reynolds number, a laminar/transitional boundary layer was observed on the airfoil pressure surface due to relaminarisation of the flow. This study aimed at improving the understanding of the relationship between the vortical velocity field and its surface pressure signature which is a matter of relevance for the so-called airfoil self-noise and for the vibration phenomena observed in ship hulls. A NACA0012 airfoil of 30cm chord and aspect ratio of 1 placed at the exit of an open-circuit blower type wind tunnel was used in the investigation. Two different flow conditions corresponding to Reynolds numbers based on the chord of the airfoil of Rec=2×105 and 4×105 and three different angles of attack have been analysed. Simultaneous measurements of the unsteady surface pressure fluctuations and of the velocity field in the boundary layer and wake of the airfoil were performed, allowing the calculation of cross-correlations and cross-spectra between the two components of the velocity and the surface pressure. This has permitted the analysis of the surface pressure generating flow structures and revealed information about the sources of wall pressure fluctuations, which are closely related to those of the radiated noise.

Shape Optimization of a Regenerative Blower Used for Building Fuel Cell System

This paper describes the optimal design of a Cathode blower used for a building fuel cell system. The Cathode air blower has a regenerative blower type. Two design variables, extension angle and number of impeller blade are introduced to enhance the blower performance. Pressure and efficiency of the blower are selected as an object function, and the optimal design is performed by a response surface method. Three-dimensional Navier-Stokes equations are introduced to analyze the performance and internal flow of the blower and to find the value of object function for the training data. Throughout the design optimization, it is found that an extension angle is effective to increase blower efficiency in the blower. The pressure rise for the optimal blower is successfully increased up to 3.17% compared with that of reference one at the design flow rate. It is noted that low velocity region disturbs to make strong recirculation flow in the each blade passage, thus increases local pressure loss. Detailed flow field inside a regenerative blower is also analyzed and compared.

Shape Optimization of a Regenerative Blower Used for Building Fuel Cell System

This paper describes the optimal design of a Cathode blower used for a building fuel cell system. The Cathode air blower has a regenerative blower type. Two design variables, extension angle and number of impeller blade are introduced to enhance the blower performance. Pressure and efficiency of the blower are selected as an object function, and the optimal design is performed by a response surface method. Three-dimensional Navier-Stokes equations are introduced to analyze the performance and internal flow of the blower and to find the value of object function for the training data. Throughout the design optimization, it is found that an extension angle is effective to increase blower efficiency in the blower. The pressure rise for the optimal blower is successfully increased up to 3.17% compared with that of reference one at the design flow rate. It is noted that low velocity region disturbs to make strong recirculation flow in the each blade passage, thus increases local pressure loss. Detailed flow field inside a regenerative blower is also analyzed and compared.

Mitigation of flow separation using DBD plasma actuators on airfoils: A tool for more efficient wind turbine operation

In this study, dielectric barrier discharge plasma actuators (DBD-PA) were used to actively control flow separation over a NACA0024 airfoil. Experiments were conducted at a free stream velocity up to U ≈ 10 m/s ( Re ≈ 1.3 × 10 5) in an open-circuit blower type wind tunnel with a test section measuring 200 mm × 200 mm × 600 mm. The airfoil model was designed specifically to incorporate minimum flow disturbances from the components of the DBD-PA and was made using rapid prototyping. A sheet of dielectric polyimide (125 μm) with copper electrodes (35 μm) was attached to the outer surface of the airfoil. A layer of DBD plasma across the airfoil was produced when a peak-to-peak voltage of V p-p = 8.0 kV was applied between top and bottom electrodes at a frequency of f p = 9.0 kHz. This development of plasma produced a tangential air jet across the surface of the airfoil, which reached its maximum value ( u j-max ) in the range of 0.5 m/s < u j-max < 0.7 m/s. Varying degrees of separation flow control was observed under these conditions. Performance comparisons were made between electrodes located at the leading edge (LE) and the quarter chord (QC, 25% of chord length) at angles of attack of α = 8°, 12°, 16°. The plasma-induced jet velocities and flow profiles were measured using particle image velocimetry (PIV). Characteristics such as power consumption, voltage waveform, and current magnitude were quantified through the use of a digital oscilloscope.

F301 CONTROL OF SEPARATION FLOW FROM AIRFOIL BY FUNCTIONAL JET USING DBD PLASMA ACTUATOR(Components-1)

Using a dielectric barrier discharge plasma actuator (DBD-PA), an active control system for flow separation around the MEL001 airfoil was attempted successfully at Re = 3.2×10^4. DBD-PA consists of top and bottom electrodes and a dielectric layer placed between the electrodes. Tangential jet velocities reach their maximum (V_<j-max>) in the range of 0.12 &le; V_<j-max> &le; 1.05 m/s, when bipolar sinusoidal wave voltages are applied, ±2.0, ±2.25, ±2.5, ±2.75, ±3.0 kV at 50 kHz. A series of experiments was carried out in the open-circuit blower type wind tunnel with 200mm×200mm×500mm test section under free stream velocity of U_∞ = 3.2 m/s. A DBD plasma actuator was installed on the MEL001 airfoil (chord length: L = 50 mm, wingspan: W = 200 mm). The wing was set in the test section with angles of attack (a) at a = 8.2 and 12.0 degrees. The effective jet velocities and power consumptions required to suppress flow separation were estimated by the velocity distributions around the airfoil and the current and voltage data so far accumulated on DBD-PA.

Study on operating characteristics of fuel cell powered electric vehicle with different air feeding systems

In this paper the modeling of a fuel cell powered electric vehicle is presented. The fuel cell system consisting of a proton exchange membrane (PEM) fuel cell stack and balance of plant (BOP) was co-simulated with a commercial vehicle simulation program. The simulation program calculates the load of the fuel cell depending on the driving mode of the vehicle and also calculates the overall efficiency and each parasitic loss by applying the load in the fuel cell model that is used to estimate the performance of the entire vehicle system by calculating the acceleration performances and fuel economy of the vehicle. Two types of air feeding systems (blower type and compressor type) were modeled by using MATLAB/Simulink environment and the effect of fuel cell stack size (number of cells, cell area) on the fuel economy and performance of the fuel cell powered vehicle was investigated. Using a driving cycle of FTP-75, the required power, BOP component power loss, and system efficiency for two types of fuel cell systems were analyzed. Through this study, we could get a basic insight into the fuel cell powered electric vehicle and its characteristics.

SF6and O2Effects on PR Ashing in N2Atmospheric Dielectric Barrier Discharge

Photo Resist (PR) ashing process was carried out with the atmospheric pressure- dielectric barrier discharge (ADBD) using <TEX>$SF_6/N_2/O_2$</TEX>. Ashing rate (AR) was sensitive to the mixing ratio of the oxygen and nitrogen of the blower type of ADBD asher. The maximum AR of 5000 A/min was achieved at 2% of oxygen in the <TEX>$N_2$</TEX> plasma. With increasing the oxygen concentration to more than 2% in the <TEX>$N_2$</TEX> plasma, the discharge becomes weak due to the high electron affinity of oxygen, resulting in the decrease of AR. When adding 0.5% of SF6 to <TEX>$O_2/N_2$</TEX> mixed plasma, the PR AR increased drastically to 9000 A/min and the ashed surface of PR was smoother compared to the processed surface without <TEX>$SF_6$</TEX>. Carbon Fluorinated polymer may passivate the PR surface. It was also observed that the glass surface was not damaged by the fluorine.

Effects of key operating parameters on the efficiency of two types of pem fuel cell systems (High-Pressure and Low-Pressure operating) for Automotive Applications

The proton exchange membrane (PEM) fuel cell system consisting of stack and balance of plant (BOP) was modeled in a MATLAB/Simulink environment. High-pressure operating (compressor type) and low-pressure operating (air blower type) fuel cell systems were considered, The effects of two main operating parameters (humidity and the pressure of the supplied gas) on the power distribution characteristics of BOP and the net system efficiency of the two systems mentioned above were compared and discussed. The simulation determines an optimum condition regarding parameters such as the cathode air pressure and the relative humidity for maximum net system efficiency for the operating fuel cell systems. This study contributes to get a basic insight into the fuel cell stack and BOP component sizing. Further research using multiobject variable optimization packages and the approach developed by this study can effectively contribute to an operating strategy for the practical use of fuel cell systems for vehicles.

Experimental investigation of noise sources in cross-flow fans

Cross-flow fans are unusual types of blowers which operate in a fundamentally different way from axial or centrifugal fans. The flow enters and leaves the impeller in a direction vertical to its axis and passes the blade row twice, first radially inward and then radially outward. Hence, cross-flow fans are basically two-stage fans. Aerodynamic and acoustic modeling of cross-flow fans is extremely difficult because of the complexity of the flow field in the rotating impeller channels with a reversal of the flow direction during each revolution and large regions of severe flow separations. To obtain experimental input data for modeling efforts, experiments were performed with a scaled up model fan. The fan was installed in an open-inlet/ducted outlet test rig. Measurements were made of the unsteady pressures on the impeller blades and on the fan casing, in particular the vortex wall. The flow fields inside the impeller and at its outer periphery were studied by using hot wire anemometry and a three-hole probe. The effect of different casing geometries was examined. A simple model for broadband noise radiation involving surface dipole sources as suggested in an early paper by Sharland [JSV 1, 302–322 (1964)] predicts the spectrum measured in an anechoically terminated outlet duct reasonably well for Now with Behr GmbH &amp; Co., Mauserstrasse 3, 70469 Stuttgart, Germany

Oxygen transfer and aeration efficiency - influence of diffuser submergence, diffuser density, and blower type

The main factors of fine bubble aeration systems in uniform arrangement in clean water are the air flow rate, the depth of submergence of the diffusers, and the diffuser density. While the influence of the air flow rate on the oxygen transfer parameters is known, knowledge of the influence of the depth of submergence and the diffuser density on the specific oxygen transfer efficiency SOTE [%/m] and on the specific oxygen absorption SOA [g/m3·m at STP] is very limited. Both parameters are of great importance in dimensioning fine bubble aeration systems. Therefore, a literature review was conducted to show the influence of the diffuser submergence and density and the type of blower on oxygen transfer and aeration efficiency. The main review results are, that higher values of specific oxygen absorption can be obtained at higher diffuser density; secondly, the volumetric oxygen transfer rate VOTR [g/m3·h] is higher with increasing depth of submergence at the same air flow rate. Also it can be stated that with greater depth of submergence the specific oxygen absorption [g/m3·m at STP] is reduced. Dependent on the air flow rate and the pressure head, the energy consumption [Wh/m3·m at STP] of the blowers used in wastewater treatment plants is different. For example, the energy consumption varies from 4.3 [Wh/m3·m at STP] (positive displacement blower) to 3.0 [Wh/m3·m at STP] (turbo-compressors) at a pressure of 10 m and an air flow rate of 5,000 m3/h at STP. From the results of the literature review the following conclusions can be drawn: (1) High specific oxygen absorption values (SOA) [g/m3·m at STP] can be achieved applying shallow tanks, high diffuser densities and low specific air flow rates; (2) High aeration efficiencies (AE) [kg/kWh] can be obtained by applying high volumetric oxygen transfer rates and adequate selection of the blowers used at the wastewater treatment plants.

Prediction and reduction of centrifugal blower noises

This paper presents the results of an investigation of centrifugal blower noises. Experiments on three different types of blowers were conducted to determine the major noise generation mechanisms. The information thus gained has led to an innovative noise reduction method utilizing a stationary, noncontacting transition mesh. Experiments showed that an overall noise reduction of 3 to 5 dB was achieved for all the blowers running at impeller speeds in the range of 10 to 30 m/s. In addition, a semianalytical model was developed to predict noise spectra from dimensionally similar centrifugal blowers. This model yielded an acoustic power proportional to the fourth power of the blower speeds. Comparisons of the calculated and measured noise spectra from different blowers running under various speeds were demonstrated. Good agreements were obtained in all cases. [Work supported by Ford Motor Company.]

Oxygen transfer and aeration efficiency — Influence of diffuser submergence, diffuser density, and blower type

The main factors of fine bubble aeration systems in uniform arrangement in clean water are the air flow rate, the depth of submergence of the diffusers, and the diffuser density. While the influence of the air flow rate on the oxygen transfer parameters is known, knowledge of the influence of the depth of submergence and the diffuser density on the specific oxygen transfer efficiency SOTE [%/m] and on the specific oxygen absorption SOA [g/m3·m at STP] is very limited. Both parameters are of great importance in dimensioning fine bubble aeration systems. Therefore, a literature review was conducted to show the influence of the diffuser submergence and density and the type of blower on oxygen transfer and aeration efficiency. The main review results are, that higher values of specific oxygen absorption can be obtained at higher diffuser density; secondly, the volumetric oxygen transfer rate VOTR [g/m3·h] is higher with increasing depth of submergence at the same air flow rate. Also it can be stated that with greater depth of submergence the specific oxygen absorption [g/m3·m at STP] is reduced. Dependent on the air flow rate and the pressure head, the energy consumption [Wh/m3·m at STP] of the blowers used in wastewater treatment plants is different For example, the energy consumption varies from 4.3 [Wh/m3·m at STP] (positive displacement blower) to 3.0 [Wh/m3·m at STP] (turbo-compressors) at a pressure of 10 m and an air flow rate of 5,000 m3/h at STP.From the results of the literature review the following conclusions can be drawn: (1) High specific oxygen absorption values (SOA) [g/m3·m at STP] can be achieved applying shallow tanks, high diffuser densities and low specific air flow rates; (2) High aeration efficiencies (AE) [kg/kWh] can be obtained by applying high volumetric oxygen transfer rates and adequate selection of the blowers used at the wastewater treatment plants.

The Design of Rotary Pumps and Systems to Provide Clean Vacua

The oil sealed rotary pump is the most common component used in vacuum systems but such pumps when charged with mineral oil can be a major source of organic backstreaming. Work in our laboratory has been concerned with studying (i) the mechanisms by which volatile organic material is formed within and released from working pumps and (ii) backstreaming under conditions where gaseous diffusion, gas flow and pipeline conductance can determine its flow rate into the vessel. Arising from these studies has been the possibility of showing that backstreaming can be reduced to negligible levels by the use of adsorption traps to eliminate oil molecules from the vacuum atmosphere. Unfortunately, such traps may impair the ultimate vacuum achieved by also trapping water vapor. This can be overcome by using a trapped oil sealed pump to back a dry vacuum stage. The dry stage can be of the blower type (out-of-contact). Higher compression ratios are possible with in-contact vane pumps which depend on use of materials with a low coefficient of friction and a pump is herewith described. In the conclusion, some of the characteristics of an alternative lubricating fluid (fluorocarbon) are described.