Іmprovement of driving-speed properties improvement of the method for selecting the parameters of the motor-transmission unit car

2021 ◽  
Vol 13 (1) ◽  
pp. 111-117
Author(s):  
Mikhail Podrigalo ◽  
◽  
Volodymyr Krasnokutskyi ◽  
Vitaliy Kashkanov ◽  
Olexander Tkachenko ◽  
...  
Keyword(s):  
Aerodynamic Drag ◽  
Dynamic Properties ◽  
Aerodynamic Characteristics ◽  
Gear Ratio ◽  
Design Stage ◽  
Transmission Unit ◽  
Air Resistance ◽  
Design Speed ◽  
Maximum Design ◽  
Engine Power

Aerodynamic characteristics have a major impact on the energy efficiency and traction and speed properties of the vehicle. In this article, based on previous studies of the aerodynamic characteristics of various car models, we propose an improved method for selecting engine and transmission parameters at the design stage. The aim of the study is to improve the dynamic properties of the car by improving the method of selecting the main parameters of the engine-transmission unit by refining the calculation of aerodynamic drag. To achieve it, the following tasks must be solved: to specify the method of selecting the maximum effective engine power; to specify a technique of definition of the maximum constructive speed of the car; to develop a technique for selecting gear ratios. The aerodynamic resistance to the movement of the vehicle is determined by the frontal coefficient of the specified resistance, the density of the air, the area of the frontal resistance and the speed of the vehicle. It is known from classical works on the aerodynamics of a car that in the range of vehicle speeds from 20 m / s to 80 m / s, taking the law of squares when assessing the force of air resistance, it is necessary to change the coefficient of frontal aerodynamic drag depending on the speed of the car. However, when carrying out calculations, this coefficient is taken constant, which leads to obtaining large values of the air resistance force at high speeds and lower at low speeds. There are two possible ways to improve the dynamic properties and energy efficiency of the car during its modernization (increasing the maximum design speed of the car by reducing the gear ratio in higher gear; reducing the maximum efficiency of the engine while maintaining the previous gear ratio in higher gear). As a result of the study, the method of selection (maximum effective engine power; maximum design speed of the car; gear ratios) at the design stage of the parameters of the motor-transmission unit of the car has been improved.

Aerodynamic Analysis of the Preliminary Design of SURIAKAR 4 Using CFD

2014 ◽  
Vol 629 ◽  
pp. 507-512
Author(s):  
Lai Gwo Sung ◽  
Wan Zaidi Wan Omar ◽  
Ahmad Zafri Zainudin ◽  
S. Mansor ◽  
Tholudin Mat Lazim
Keyword(s):  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Rear Wheel ◽  
Preliminary Design ◽  
Ansys Fluent ◽  
Design Speed ◽  
Drag And Lift ◽  
The Stability ◽  
The Right ◽  
Grid Independence

A four-wheel solar car, the SURIAKAR 4, was designed based on the revised regulations of the Challenger Class World Solar Challenge (2013). It is a four-wheel car with the front and back wheels enclosed in a wind cheating cover. The cockpit is located in such a way that it sits between the front and rear wheel, within the wheel cover on the right side of the car. This paper investigates the aerodynamic characteristics of the car, especially the drag and lift forces, and other forces and moments that determine the stability of the car using CFD package ANSYS Fluent. The model analysis was done with 2.23 million elements after a thorough grid independence study was conducted. The drag coefficient of SURIAKAR 4 is 0.1817. With a frontal area of 0.8934 m2 and at the design speed, the car requires 2132 W of power to overcome this aerodynamic drag. The results also showed that the airflow quality around the car is relatively well-behaved, with only a few turbulent flow points identified. This flow incurs drag penalty and thus have to be modified.

scholarly journals Fixation of Tarpaulin Sheet of Platform HDV and its Impact to Air Resistance

2018 ◽  
Vol 14 (1) ◽  
pp. 6-10
Author(s):  
Tomáš Skrúcaný ◽  
Martin Vojtek ◽  
Gabriel Suchter
Keyword(s):  
Aerodynamic Drag ◽  
Technical Standard ◽  
Air Resistance ◽  
Velocity Changes ◽  
Vehicle Deceleration ◽  
Engine Power

Abstract This paper due to determine an aerodynamic drag for different ways of tarpaulin fixation, specifically tarpaulin tension and disposition on platform-type body of a HDV. More positions of the tarpaulin were investigated. Determination of the resistances was done by coast down test of the vehicle according to Slovakian technical standard (STN). The aerodynamic drag was calculated from actual vehicle deceleration during the coast down test from the actual velocity changes. The vehicle actual velocity was measured by GPS logging device. Results are values of resistance, which affect the vehicle and their sum represents the actual engine power needed for vehicles driving.

scholarly journals INCREASING THE COMFORTABILITY OF THE VEHICLE DURING ACCELERATION BY IMPROVING THE DESIGN AND CONTROL METHODS OF THE MOTOR-TRANSMISSION UNIT

2021 ◽  
pp. 81-85
Author(s):  
Mikhail Podrigalo ◽  
Volodymir Krasnokutskyi ◽  
Olexander Tkachenko
Keyword(s):  
High Speed ◽  
Aerodynamic Resistance ◽  
Gear Ratio ◽  
Continuously Variable Transmission ◽  
Engine Torque ◽  
Transmission Unit ◽  
Variable Transmission ◽  
Acceleration And Deceleration ◽  
Speed Mode ◽  
Engine Power

The derivative of acceleration with respect to time is used to evaluate and ensure driving comfort during acceleration and deceleration. Frequent and rapid changes in acceleration means frequent and rapid deformation, which can lead to the destruction of the load. The article proposes to minimize the amount of acceleration due to the rational choice of transmission ratios in intermediate gears and the law of changing the engine torque. The use of continuously variable transmissions allows you to solve the problem by choosing a rational law for changing the gear ratio of the transmission. The method of selection at the stage of car design of the maximum effective engine power and transmission ratio in top gear is proposed, taking into account the improved formula for calculating the aerodynamic resistance to motion. The required laws of change in the efficiency of the torque and engine power have been determined. The use of a continuously variable transmission allows the engine to operate at a constant high-speed mode and provides control over the acceleration of the car by changing the fuel supply. It is determined that the engine power expended on the movement with the adjustment of the acceleration of the car will be less than with unregulated acceleration if the exponent at the speed of the car, obtained experimentally, is less than one. Keywords: car; comfort; continuously variable transmission; motor-transmission unit; power; overclocking; aerodynamic resistance; gear ratio

Measured natural periods of concrete shear wall buildings: insights for the design of Canadian buildings

2012 ◽  
Vol 39 (8) ◽  
pp. 867-877 ◽  
Author(s):  
Damien Gilles ◽  
Ghyslaine McClure
Keyword(s):  
Seismic Analysis ◽  
Dynamic Properties ◽  
Response Spectrum ◽  
Shear Wall ◽  
Mode Shapes ◽  
Design Stage ◽  
Base Shear ◽  
Period Equation ◽  
Input Load ◽  
Structural Engineers

Structural engineers routinely use rational dynamic analysis methods for the seismic analysis of buildings. In linear analysis based on modal superposition or response spectrum approaches, the overall response of a structure (for instance, base shear or inter-storey drift) is obtained by combining the responses in several vibration modes. These modal responses depend on the input load, but also on the dynamic characteristics of the building, such as its natural periods, mode shapes, and damping. At the design stage, engineers can only predict the natural periods using eigenvalue analysis of structural models or empirical equations provided in building codes. However, once a building is constructed, it is possible to measure more precisely its dynamic properties using a variety of in situ dynamic tests. In this paper, we use ambient motions recorded in 27 reinforced concrete shear wall (RCSW) buildings in Montréal to examine how various empirical models to predict the natural periods of RCSW buildings compare to the periods measured in actual buildings under ambient loading conditions. We show that a model in which the fundamental period of RCSW buildings varies linearly with building height would be a significant improvement over the period equation proposed in the 2010 National Building Code of Canada. Models to predict the natural periods of the first two torsion modes and second sway modes are also presented, along with their uncertainty.

Influence of Engine Cabin Simplification on Aerodynamic Characteristics of Car

2014 ◽  
Vol 1042 ◽  
pp. 188-193 ◽  
Author(s):  
Xing Jun Hu ◽  
Jing Chang
Keyword(s):  
Numerical Simulation ◽  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Thin Plates ◽  
Average Thickness ◽  
Two Dimensional ◽  
Engine Cooling ◽  
Aerodynamic Drag Coefficient ◽  
Simulation Results ◽  
The Impact

In order to analyze the impact of engine cabin parts on aerodynamic characteristics, the related parts are divided into three categories except the engine cooling components: front thin plates (average thickness of 2mm), bottom-suspension and interior panels. The aerodynamic drag coefficient (Cd) were obtained upon the combination schemes consisting of the three types of parts by numerical simulation. Results show that Cd by simulation is closer to the test value gained by the wind tunnel experiment when front thin plates were simplified to the two-dimensional interface with zero thickness. The error is only 5.23%. Meanwhile this scheme reduces grid numbers, thus decreasing the calculating time. As the front thin plates can guide the flow, there is no difference on the Cd values gained from the model with or without bottom-suspension or interior panels when the engine cabin contains the front thin plates; while only both bottom-suspension and interior panels are removed, the Cd value can be reduced when the cabin doesn’t contain the front thin plates.

scholarly journals Designing a ship course controller by applying the adaptive backstepping method

2012 ◽  
Vol 22 (4) ◽  
pp. 985-997 ◽  
Author(s):  
Anna Witkowska ◽  
Roman Śmierzchalski
Keyword(s):  
Time Domain ◽  
System Performance ◽  
Control Algorithm ◽  
Control Structure ◽  
Dynamic Properties ◽  
Time Domain Analysis ◽  
Design Stage ◽  
Backstepping Method ◽  
Adaptive Backstepping ◽  
Nonlinear Static

The article discusses the problem of designing a proper and efficient adaptive course-keeping control system for a seagoing ship based on the adaptive backstepping method. The proposed controller in the design stage takes into account the dynamic properties of the steering gear and the full nonlinear static maneuvering characteristic. The adjustable parameters of the achieved nonlinear control structure were tuned up by using the genetic algorithm in order to optimize the system performance. A realistic full-scale simulation model of the B-481 type vessel including wave and wind effects was applied to simulate the control algorithm by using time domain analysis.

scholarly journals Reduction of Aerodynamic Drag of Heavy Vehicles using CFD

2021 ◽  
Vol 9 (8) ◽  
pp. 2670-2678
Author(s):  
Priyank Kothari
Keyword(s):  
Fuel Economy ◽  
Aerodynamic Drag ◽  
Fuel Efficiency ◽  
Heavy Vehicles ◽  
Heavy Trucks ◽  
Air Resistance

Abstract: Aerodynamic drag is the force that opposes an object’s motion. When a vehicle no matter the size, is designed to allow air to move fluidly over its body, aerodynamic drag will have less of an impact on its performance and fuel economy. Heavy trucks burn a significant amount of fuel as to overcome the air resistance. More than 50% of an 18-wheeler’s fuel is spent reducing aerodynamic drag on the highways. Keywords: Aerodynamics, Heavy vehicles, ANSYS, Aerodynamic Drag, Fuel efficiency.

scholarly journals Bearing friction effect on cup anemometer performance modelling

2021 ◽  
Vol 2090 (1) ◽  
pp. 012101
Author(s):  
D Alfonso-Corcuera ◽  
S. Pindado ◽  
M Ogueta-Gutiérrez ◽  
A Sanz-Andrés
Keyword(s):  
Rotation Rate ◽  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Friction Torque ◽  
Performance Modelling ◽  
Friction Forces ◽  
Aerodynamic Drag Coefficient ◽  
Yaw Angle ◽  
Cup Anemometer ◽  
Bearing Friction

Abstract In the present work, the effect of the friction forces at bearings on cup anemometer performance is studied. The study is based on the classical analytical approach to cup anemometer performance (2-cup model), used in the analysis by Schrenk (1929) and Wyngaard (1981). The friction torque dependence on temperature was modelled using exponential functions fitted to the experimental results from RISØ report #1348 by Pedersen (2003). Results indicate a logical poorer performance (in terms of a lower rotation speed at the same wind velocity), with an increase of the friction. However, this decrease of the performance is affected by the aerodynamic characteristics of the cups. More precisely, results indicate that the effect of the friction is modified depending on the ratio between the maximum value of the aerodynamic drag coefficient (at 0° yaw angle) and the minimum one (at 180° yaw angle). This reveals as a possible way to increase the efficiency of the cup anemometer rotors. Besides, if the friction torque is included in the equations, a noticeable deviation of the rotation rate (0.5-1% with regard to the expected rotation rate without considering friction) is found for low temperatures.

scholarly journals Evaluation of Power Indicators of the Automobile Engine

2018 ◽  
Vol 7 (4.3) ◽  
pp. 130 ◽  
Author(s):  
Hayder Abed Dhahad ◽  
Wissam Hameed Alawee ◽  
Andrii Marchenko ◽  
Dmytro Klets ◽  
Oleg Akimov
Keyword(s):  
Rational Choice ◽  
Dynamic Capabilities ◽  
Operating Conditions ◽  
Design Stage ◽  
Design Features ◽  
Automobile Engine ◽  
Power Characteristics ◽  
The Impact ◽  
Analytical Expressions ◽  
Engine Power

A method for estimating the power characteristics of the car engine in various driving regimes is proposed. It is determined that the volume of the free power (engine power reserve) allows the driver to implement the turning parameters and the time of its completion, which are set by the steering parameters, position and the speed of the steering wheels rotation. The engine power reserve is necessary to provide the required maneuverability indicators. The engine power during maneuvering is spent on overcoming the resistance to movement and on providing the impact controlled by the maneuver. The first component of the engine power can be called connected, and the second one can be called the free one or a controlled component. The received analytical expressions allow carrying out at the design stage a rational choice of capacity of the engine by the condition of maintenance of demanded properties of maneuverability. The developed method for constructing the refined acceleration characteristics of the engine makes it possible to determine the dynamic capabilities of the car, taking into account its design features and operating conditions. 

Experimental Studies on Aerodynamic Characteristics of Pantograph System According to the Pantograph Cover Configurations for High Speed Train

2011 ◽  
Author(s):  
Yeongbin Lee ◽  
Minho Kwak ◽  
Kyu Hong Kim ◽  
Dong-Ho Lee
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Aerodynamic Force ◽  
Experimental Studies ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Experimental Models ◽  
High Speed Train ◽  
Drag And Lift

In this study, the aerodynamic characteristics of pantograph system according to the pantograph cover configurations for high speed train were investigated by wind tunnel test. Wind tunnel tests were conducted in the velocity range of 20∼70m/s with scaled experimental pantograph models. The experimental models were 1/4 scaled simplified pantograph system which consists of a double upper arm and a single lower arm with a square cylinder shaped panhead. The experimental model of the pantograph cover is also 1/4 scaled and were made as 4 different configurations. It is laid on the ground plate which modeled on the real roof shape of the Korean high speed train. Using a load cell, the aerodynamic force such as a lift and a drag which were acting on pantograph system were measured and the aerodynamic effects according to the various configurations of pantograph covers were investigated. In addition, the total pressure distributions of the wake regions behind the panhead of the pantograph system were measured to investigate the variations of flow pattern. From the experimental test results, we checked that the flow patterns and the aerodynamic characteristics around the pantograph systems are varied as the pantograph cover configurations. In addition, it is also found that pantograph cover induced to decrease the aerodynamic drag and lift forces. Finally, we proposed the aerodynamic improvement of pantograph cover and pantograph system for high speed train.

Sign in / Sign up

Export Citation Format

Share Document