Explicit Formula for Estimating Aerodynamic Drag on Trains Running in Evacuated Tube Transportation

2013 ◽  
Vol 307 ◽  
pp. 156-160
Author(s):  
Yao Ping Zhang
Keyword(s):  
Explicit Formula ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Research Work ◽  
Maglev Train ◽  
Isaac Newton ◽  
Fluent Software ◽  
Evacuated Tube Transportation ◽  
Theory Research ◽  
Evacuated Tube

Because of reducing aerodynamic drag, the maglev train could run at a high-speed in the partial vacuum tube. Scientists of some conutries such as U.S., Swiss and China, have started the research work on high-speed tube trains. In this situation, evacuated tube transportation aerodynamics becomes an important theory research aspect, in which the main study content is how to calculate aerodynamic drag. Based on the explicit formula for estimating aerodynamic drag on moving body in an infinite boundary surroundings put up by Isaac Newton, the evacuated tube surroundings is analyzed and the explicit formula with blockage ratio as an independent variable for estimating aerodynamic drag acted on trains running in the evacuated tube which is a finite space is deduced. With the calculation case, compared with the results came out from the explicit formula got in this paper and the results got by Fluent software, it was found that those results are closed. Thus, the explicit formula created in this paper for conveniently estimating aerodynamic drag based on trains running in evacuated tube transportation is credible.

scholarly journals Influence of the Topological Structures of the Nose of High-Speed Maglev Train on Aerodynamic Performances

2021 ◽  
Author(s):  
Yeteng Wang ◽  
Zhenxu Sun
Keyword(s):  
High Speed ◽  
Aerodynamic Drag ◽  
Aerodynamic Force ◽  
Design Method ◽  
Aerodynamic Performance ◽  
Superior Performance ◽  
Maglev Train ◽  
Topological Structures ◽  
Aerodynamic Shape ◽  
Vehicle Modeling Function

Abstract In the past few years, considerable attention has been paid to high-speed maglev train in the field of rail transit. The design speed of the high-speed maglev train is 600km/h, which is significantly higher than that of the high-speed train. With the increase in operating speed, high-speed maglev trains have higher requirements for aerodynamic shape. Superior performance, the beautiful aerodynamic shape is an important direction for the development of high-speed maglev trains. Based on the Vehicle Modeling Function (VMF) method, the current research has developed a parametric shape design method suitable for the aerodynamic shape of the maglev train’s nose. This method can obtain different topological structures of the high-speed maglev train’s nose. The current research uses this method to generate four maglev train noses with large appearance differences and uses these train noses to construct four simplified high-speed maglev models. Then this study numerically analyzes the flow fields of different train models and compares the differences in aerodynamic performance including aerodynamic drag, aerodynamic lift and wake characteristics. The Q-criterion is used to study the vortex structure and mechanism of different train wake regions, and the vortex propagation process is studied by turbulence kinetic energy (TKE). Studying the difference in the aerodynamic force of different topological shapes will help to improve the aerodynamic performance of high-speed maglev trains.

scholarly journals Redchyts Evaluation of aerodynamic and thermal loads on the HYPERLOOP capsule fuselage in a partly evacuated tube

2019 ◽  
Vol 4 (123) ◽  
pp. 3-12
Author(s):  
Oleh Borysovych Polovyi ◽  
Dmytro Oleksandrovych Redchyts
Keyword(s):  
High Speed ◽  
Stokes Equations ◽  
Aerodynamic Drag ◽  
Negative Impact ◽  
Transportation Systems ◽  
Transport Systems ◽  
Aerodynamic Heating ◽  
Thermal Loads ◽  
Important Place ◽  
Evacuated Tube

Aerodynamics occupies an important place in the design of high-speed ground transportation systems. When a vehicle is moving at a speed above 500 km/h under atmospheric pressure, the main energy is spent to overcome the aerodynamic drag. Creating a rarefied atmosphere inside a sealed pipe in order to significantly reduce energy loss is one of the key ideas of the HYPERLOOP project [1].The paper assesses the aerodynamic and thermal loads on the HYPERLOOP capsule fuselage in a partly evacuated tube based on the numerical solution of the Navier-Stokes equations of compressible flow closed by a differential turbulence model [2-4]. Numerical modeling was carried out with the help of the computational fluid dynamics software developed by the scientific researchers of the Institute of Transport Systems and Technologies of the National Academy of Sciences of Ukraine [5].It was shown that even under conditions of low air pressure in a partly evacuated tube the high-speed movement of the HYPERLOOP capsule will be accompanied by the formation of local supersonic zones, shock waves and non-stationary vortex systems. The structure of the flow essentially depends on geometry of the streamlined capsule and the speed of its movement.It was found that the flow structure and the values of aerodynamic dimensionless coefficients weakly depend on the pressure in the partly evacuated tube. Thus, the aerodynamic forces acting on the HYPERLOOP capsule at the same speeds are almost directly proportional to the pressure value in the tube.A certain problem in the design of the HYPERLOOP type high-speed vehicles will be the aerodynamic heating of the capsule fuselage. When the capsule moves at transonic speed the temperature of the outer surface of the capsule will be 60÷900 C. This heat load can have a negative impact on the performance of onboard power supply and control systems, as well as on the ensuring of the passengers’ comfort on the way.

scholarly journals The approach to calculate the aerodynamic drag of maglev train in the evacuated tube

2013 ◽  
Vol 21 (3) ◽  
pp. 200-208 ◽  
Author(s):  
Jiaqing Ma ◽  
Dajing Zhou ◽  
Lifeng Zhao ◽  
Yong Zhang ◽  
Yong Zhao
Keyword(s):  
Aerodynamic Drag ◽  
Maglev Train ◽  
Evacuated Tube

scholarly journals Study on the effect of dimple position on drag reduction of high-speed maglev train

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Dan Zhou ◽  
Liliang Wu ◽  
Changda Tan ◽  
Tian'en Hu
Keyword(s):  
High Speed ◽  
Aerodynamic Drag ◽  
Lift Coefficient ◽  
Three Dimensional ◽  
Wind Tunnel Test ◽  
Ground Truth ◽  
Detached Eddy Simulation ◽  
Maglev Train ◽  
Simulation Accuracy ◽  
Drag And Lift

Abstract Transient numerical simulations were carried out by placing dimples at the top, sides and bottoms of the tail car streamline area of a high-speed maglev train. The results of an improved delayed detached eddy simulation turbulence model using three-dimensional compressible Navier-Stokes and shear-stress transport K-Omega double equations were compared to the results of a wind tunnel test to verify the numerical simulation accuracy, within 5% of the ground truth, which is an acceptable precision range. The results show that dimples arranged on the streamline area atop the train tail car affected the locations at which the airflow at the top and bottom of the train met and weakened the strength of the wake. The aerodynamic drag and lift coefficient decreased by 3.40% and 4.27%, respectively. When the dimples were arranged on the streamline area at the sides or bottoms of the train tail car, they had little effect on the top of the tail car, so they did not destroy the balance of the airflow at the top and bottom. They also had little influence on the development of wake topology. Therefore, the aerodynamic drag and lift of the train changed little.

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