scholarly journals Computational Aerodynamics Analysis of Non-Symmetric Multi-Element Wing in Ground Effect with Humpback Whale Flipper Tubercles

Fluids ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 247
Author(s):  
Benjamin Arrondeau ◽  
Zeeshan A. Rana
Keyword(s):  
Flow Behavior ◽  
Ground Effect ◽  
Humpback Whale ◽  
Main Element ◽  
Aerodynamic Coefficients ◽  
Computational Aerodynamics ◽  
Sst Turbulence Model ◽  
Wing Geometry ◽  
Front Wing ◽  
The Cost

The humpback whale flipper tubercles have been shown to improve the aerodynamic coefficients of a wing, especially in stall conditions, where the flow is almost fully detached. In this work, these tubercles were implemented on a F1 front-wing geometry, very close to a Tyrrell wing. Numerical simulations were carried out employing the k−ω SST turbulence model and the overall effects of the tubercles on the flow behavior were analyzed. The optimal amplitude and number of tubercles was determined in this study for this front wing where an improvement of 22.6% and 9.4% is achieved, respectively, on the lift and the L/D ratio. On the main element, the stall was delayed by 167.7%. On the flap, the flow is either fully detached, in the large circulation zone, or fully attached. Overall, in stall conditions, tubercles improve the downforce generation but at the cost of increased drag. Furthermore, as the tubercles are case-dependent, an optimal configuration for tubercles implementation also exists for any geometry.

scholarly journals CFD Simulation of a Hyperloop Capsule Inside a Low-Pressure Environment Using an Aerodynamic Compressor as Propulsion and Drag Reduction Method

2021 ◽  
Vol 11 (9) ◽  
pp. 3934
Author(s):  
Federico Lluesma-Rodríguez ◽  
Temoatzin González ◽  
Sergio Hoyas
Keyword(s):  
Shock Waves ◽  
Power Consumption ◽  
High Speed ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Flow Behavior ◽  
Critical Conditions ◽  
Vehicle Speed ◽  
Blockage Ratio ◽  
The Cost

One of the most restrictive conditions in ground transportation at high speeds is aerodynamic drag. This is even more problematic when running inside a tunnel, where compressible phenomena such as wave propagation, shock waves, or flow blocking can happen. Considering Evacuated-Tube Trains (ETTs) or hyperloops, these effects appear during the whole route, as they always operate in a closed environment. Then, one of the concerns is the size of the tunnel, as it directly affects the cost of the infrastructure. When the tube size decreases with a constant section of the vehicle, the power consumption increases exponentially, as the Kantrowitz limit is surpassed. This can be mitigated when adding a compressor to the vehicle as a means of propulsion. The turbomachinery increases the pressure of part of the air faced by the vehicle, thus delaying the critical conditions on surrounding flow. With tunnels using a blockage ratio of 0.5 or higher, the reported reduction in the power consumption is 70%. Additionally, the induced pressure in front of the capsule became a negligible effect. The analysis of the flow shows that the compressor can remove the shock waves downstream and thus allows operation above the Kantrowitz limit. Actually, for a vehicle speed of 700 km/h, the case without a compressor reaches critical conditions at a blockage ratio of 0.18, which is a tunnel even smaller than those used for High-Speed Rails (0.23). When aerodynamic propulsion is used, sonic Mach numbers are reached above a blockage ratio of 0.5. A direct effect is that cases with turbomachinery can operate in tunnels with blockage ratios even 2.8 times higher than the non-compressor cases, enabling a considerable reduction in the size of the tunnel without affecting the performance. This work, after conducting bibliographic research, presents the geometry, mesh, and setup. Later, results for the flow without compressor are shown. Finally, it is discussed how the addition of the compressor improves the flow behavior and power consumption of the case.

Ground effect on a cropped slender reverse delta wing with anhedral and Gurney flaplike side-edge strips

2018 ◽  
Vol 233 (7) ◽  
pp. 2433-2444 ◽  
Author(s):  
T Lee ◽  
D Huitema ◽  
P Leite
Keyword(s):  
Weight Reduction ◽  
Free Stream ◽  
Delta Wing ◽  
Ground Effect ◽  
Aerodynamic Coefficients ◽  
Side Edge ◽  
A Minor ◽  
Wing In Ground Effect

The ground effect on the aerodynamic coefficients of a cropped slender reverse delta wing equipped with anhedral and Gurney flaplike side-edge strips was investigated experimentally at Re = 3.82 × 105. In a free stream, the 30% cropping was found to cause a minor reduction in lift CL and drag CD coefficients but a promoted stall compared to the noncropped wing. The anhedral caused further CL decrease and CD increase. Meanwhile, the application of side-edge strips produced a significantly increased CL and CD with a minor change to the CL/ CD ratio as compared to the baseline wing. In ground effect, the cropped wing was, however, found to generate more lift compared to the noncropped wing as the ground was approached. The joint anhedral and SES produced a great increment in both CL and CD but a virtually unchanged CL/ CD ratio compared to their outside ground effect counterparts. The larger the side-edge strips’ height the larger the increase in CL. In short, the cropping led to a weight reduction while the addition of anhedral and SES produced a large lift augmentation of the Lippisch-type wing-in-ground effect craft.

Computational Analysis of a Inverted Double-Element Airfoil in Ground Effect

2006 ◽  
Vol 128 (6) ◽  
pp. 1172-1180 ◽  
Author(s):  
Stephen Mahon ◽  
Xin Zhang
Keyword(s):  
Flow Field ◽  
Stokes Equations ◽  
Near Field ◽  
Turbulence Models ◽  
Ground Effect ◽  
Wake Flow ◽  
Navier Stokes ◽  
Main Element ◽  
Ride Height ◽  
Navier Stokes Equations

The flow around an inverted double-element airfoil in ground effect was studied numerically, by solving the Reynolds averaged Navier-Stokes equations. The predictive capabilities of six turbulence models with regards to the surface pressures, wake flow field, and sectional forces were quantified. The realizable k−ε model was found to offer improved predictions of the surface pressures and wake flow field. A number of ride heights were investigated, covering various force regions. The surface pressures, sectional forces, and wake flow field were all modeled accurately and offered improvements over previous numerical investigations. The sectional forces indicated that the main element generated the majority of the downforce, whereas the flap generated the majority of the drag. The near field and far field wake development was investigated and suggestions concerning reduction of the wake thickness were offered. The main element wake was found to greatly contribute to the overall wake thickness with the contribution increasing as the ride height decreased.

scholarly journals Improvement of the technology of flame arrester manufacturing

2020 ◽  
pp. 29-34
Author(s):  
K. N. Pantyukhova ◽  
◽  
O. Yu. Bourgonova ◽  
Yu. O. Filippov ◽  
G. P. Ulyasheva ◽  
...  
Keyword(s):  
Nickel Powder ◽  
Spontaneous Combustion ◽  
Main Element ◽  
Hard Coal ◽  
Gas Analyzer ◽  
Flame Arrester ◽  
Spontaneous Combustion Of Coal ◽  
The Cost ◽  
Underground Method

When mining hard coal the underground method is prevailed. This method provides a higher quality of the mineral. Methane emissions occur in coal mines during the development of gasbearing seams. These emissions are the reason for the formation of an explosive mixture when mixed with mine air, and also contribute to the spontaneous combustion of coal. Methane alarms are used to monitor the mine atmosphere. Thermocatalytic sensor is the main element of such a gas analyzer. The sensor is placed in a breathable housing. This body is called a flame arrester. This article discusses the possibility of replacing the material used for the manufacture of a flame arrester. The basis of the existing material is nickel powder. It is proposed to replace it with a cermet bond. The composition of the ceramic material of the part is developed by the author and presented in the article. Replacement of material will lead to a significant reduction in the cost of the part and simplification of the manufacturing technology

Control of Separation Zone Behind a Flat Plate Under the Ground Effect Using Porous Lamination, Mathematical Modeling

2020 ◽  
pp. 2050109
Author(s):  
Kazem Reza-Asl ◽  
Saeed Foshat
Keyword(s):  
Vortex Shedding ◽  
Vortex Structure ◽  
Lift Force ◽  
Liquid Surface ◽  
Separation Zone ◽  
Flow Behavior ◽  
Ground Effect ◽  
The Body ◽  
Numerical Code ◽  
Porous Zone

Examination of the flat and curved plates flying close to the ground is an appropriate approach in understanding the complexity of flow behavior near a solid or liquid surface. When a body flies close to a surface, the vortex structure behind the body is changed; therefore, the resultant lift force is more than zero. This phenomenon is named “ground effect”. In this study, flat and curved plates submerged in the ground boundary layer were numerically investigated under the ground effect. After validating the desired numerical code, the influences of adding porous layer to the plates with [Formula: see text] attack angle were examined on vortex structure and flow separation behind the plate under the ground effect. The obtained results revealed that using a porous zone significantly reduced the separation zone and changed the vortex shedding structure downstream of the plates.

Aerodynamic Behavior of a Compound Wing Configuration in Ground Effect

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Saeed Jamei ◽  
Adi Maimun ◽  
Shuhaimi Mansor ◽  
Agoes Priyanto ◽  
Nor Azwadi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Ground Effect ◽  
Tip Vortex ◽  
Aerodynamic Coefficients ◽  
Ground Clearance ◽  
Reverse Taper ◽  
Current Experimental Data ◽  
Computational Fluid Dynamics Cfd ◽  
Ram Effect ◽  
Wing In Ground Effect

The aerodynamic coefficients of wing in ground effect can be affected with its design which can be the main parameter for efficiency of wing-in-ground effect craft. In this study, the aerodynamic coefficients of a compound wing were numerically determined in ground effect. The compound wing was divided into three parts with one rectangular wing in the middle and two reverse taper wings with an anhedral angle at the sides. An NACA6409 airfoil was employed as a section of wings. Three dimensional (3D) computational fluid dynamics (CFD) was applied as a numerical scheme. A realizable k-ε turbulent model was used for simulation the turbulent flow around the wing surfaces. For validation purpose, the numerical results of a compound wing with aspect ratio 1.25, at ground clearance of 0.15 and different angles of attack were compared with the current experimental data. Then, the aerodynamic coefficients of the compound wings were computed at various ground clearances and angle of attack of 4°. According to pressure and velocity distribution of air around wing surfaces, ground clearance had considerable effects on ram effect pressure and tip vortex of the compound wing, and aerodynamic coefficients of the compound wing had some improvements as compared with the rectangular wing.

scholarly journals Advanced Methodology for the Optimal Sizing of the Energy Storage System in a Hybrid Electric Refuse Collector Vehicle Using Real Routes

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3279 ◽  
Author(s):  
Ernest Cortez ◽  
Manuel Moreno-Eguilaz ◽  
Francisco Soriano
Keyword(s):  
Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Main Element ◽  
Optimal Sizing ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Hybrid Electric ◽  
The Cost ◽  
Optimal Space

This paper presents a new methodology for optimal sizing of the energy storage system ( E S S ), with the aim of being used in the design process of a hybrid electric (HE) refuse collector vehicle ( R C V ). This methodology has, as the main element, to model a multi-objective optimisation problem that considers the specific energy of a basic cell of lithium polymer ( L i – P o ) battery and the cost of manufacture. Furthermore, optimal space solutions are determined from a multi-objective genetic algorithm that considers linear inequalities and limits in the decision variables. Subsequently, it is proposed to employ optimal space solutions for sizing the energy storage system, based on the energy required by the drive cycle of a conventional refuse collector vehicle. In addition, it is proposed to discard elements of optimal space solutions for sizing the energy storage system so as to achieve the highest fuel economy in the hybrid electric refuse collector vehicle design phase.

Feasibility Study of Refuelling Infrastructure for Compressed Hydrogen Gas Long-Haul Heavy-Duty Trucks in Canada

2021 ◽  
Author(s):  
Wahiba Yaïci ◽  
Michela Longo
Keyword(s):  
Hydrogen Production ◽  
Diesel Fuel ◽  
Developmental Process ◽  
Hydrogen Gas ◽  
Production Costs ◽  
Main Element ◽  
Selling Price ◽  
Heavy Duty ◽  
Heavy Duty Truck ◽  
The Cost

Abstract In view of serious environmental problems occurring around the world and in particular climate change caused significantly by dangerous CO2 emissions into the biosphere in the developmental process, it has become imperative to identify alternative and cleaner sources of energy. It is now indisputable that there cannot be sustained development or meaningful growth without a commitment to preserve the environment. Compressed hydrogen is being considered as a potential fuel for heavy-duty applications because it will possibly substantially reduce toxic greenhouse gas emissions. The cost of hydrogen will be a main element in the acceptance of compressed hydrogen internal combustion vehicles in the marketplace since of its effect on the levelized cost of driving. The cost of hydrogen at the pump is determined by its production cost, which is mainly a function of the feedstock and process utilised, the distribution cost and the refuelling station cost. This paper investigates the feasibility of implementing a nationwide network of hydrogen refuelling infrastructure in order to accommodate a conversion of Canada’s long-haul, heavy-duty truck fleet from diesel fuel to hydrogen. This initiative is taken in order to reduce vehicle emissions and support Canada’s commitments to the climate plans supporting active transportation infrastructure, together with new transit infrastructure, and zero emission vehicles. Two methods, Constant Traffic and Variable Traffic, along with data about hydrogen infrastructure and vehicles, were developed to estimate fuelling requirements for Canada’s long-haul, heavy-duty truck fleet. Furthermore, a thorough economic study was conducted on various test cases to evaluate how diverse variables affects the final selling price of hydrogen. This provided insight with the understanding of what factors go into pricing hydrogen and if it can compete against diesel in the trucking market. Results revealed that the cost to purchase hydrogen is the greatest factor in the pump price of hydrogen. Due to the variability in hydrogen production, however, there is no precise cost, which makes predictions difficult. Moreover, it was found that the pump price of hydrogen is, on average, 239% more expensive than diesel fuel. Future work should concentrate on the costs and logistics of high-capacity hydrogen refuelling stations, which is required to deliver fuel to a fleet of long-haul, heavy-duty trucks. A breakdown of hydrogen production costs, with regard to the Canadian landscape and the requirements of a long-haul, heavy-duty truck fleet, may possibly give further accurate predictions of those made in this study.

scholarly journals Determination of Resistance Factor for Tortuous Paths in Drip Emitters

2017 ◽  
Author(s):  
Jaya Narain ◽  
Amos Winter
Keyword(s):  
Analytical Model ◽  
Drip Irrigation ◽  
Computational Models ◽  
Crop Yields ◽  
Flow Behavior ◽  
Resistance Factor ◽  
Analytical Models ◽  
Cfd Model ◽  
The Cost ◽  
Future Work

Drip irrigation has the potential to decrease water consumption and increase crop yields and profit. Globally, drip irrigation has had low adoption rates. There are several major barriers to adoption, including the cost of the system and its energy consumption. Mathematical models describing the behavior of drip emitters can provide insights on the performance of drip systems. The models and procedures developed in this paper can be used as a tool for the design of improved drip irrigation systems. This paper presents a method of combining a CFD model that characterizes flow through the tortuous paths of emitters with an analytical model describing pressure-compensating behavior. The CFD model detailed in this paper was verified for three commercially available emitter designs. The model fell within acceptable variation bounds when compared to experimental data. The results of CFD analysis are represented in a resistance factor that can be used in a hybrid analytical-computational model. This method requires significantly less processing than using computational models alone. Future work on this topic will detail an analytical model that accurately predicts the behavior of inline PC drip emitters of varying geometries and an optimization of the geometry to lower activation pressure and material costs. Analytical models to predict the flow behavior of a range of tortuous path designs given a prescribed geometry will also be developed.

Ground Viscous Effect on Aerodynamics of a Compound Wing with Different Reynolds Number

2013 ◽  
Vol 465-466 ◽  
pp. 379-383
Author(s):  
Saeed Jamei ◽  
Agoes Priyanto ◽  
Adi Maimun ◽  
Mohammad Mobassher Tofa ◽  
Nor Azwadi ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Boundary Layers ◽  
Numerical Study ◽  
Ground Effect ◽  
Good Method ◽  
Aerodynamic Coefficients ◽  
Moment Coefficient ◽  
Numerical Result ◽  
Computational Fluid Dynamics Cfd ◽  
Lift And Drag

The fly of wing-in-ground effect (WIG) crafts can be affected by ground boundary layers. In this study, the effect of ground viscous on aerodynamic coefficients of a compound wing of WIG craft was numerically investigated. Computational fluid dynamics (CFD) was used for numerical study. The simulations were done respect to different ground clearance and Reynolds number. A realizable k-ε turbulent model was employed for the modelling flow field around the wing area. The numerical results of the compound wing for fixed ground validated with the experimental data. Aerodynamic coefficients of the compound wing were determined for fixed and moving ground. Accordingly, the numerical result presented that lift and drag coefficients and lift to drag ratio has been affected by ground boundary layers while moment coefficient and centre of pressure of compound wing had no more variation due to remove ground viscous. The effect of ground viscous on aerodynamics of the compound wing had a slight changes respect to Reynolds number. CFD can be employed as a good method to find the influence of ground viscous on aerodynamics of WIG crafts.

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