scholarly journals A Critcal Study of Driving Performance of Heavy Duty Vehicle Running on Long Downhill Road Using Engine Brake

2014 ◽  
Vol 8 (1) ◽  
pp. 475-479 ◽  
Author(s):  
Xuan Zhao ◽  
Xiaolei Yuan ◽  
Qiang Yu
Keyword(s):  
Temperature Rise ◽  
High Speed ◽  
Driving Performance ◽  
Test Results ◽  
Heavy Duty ◽  
Heavy Duty Vehicle ◽  
Simulation Results ◽  
Heavy Duty Vehicles

For ensuring safety of heavy duty vehicles running on long downhill sections, a model was built for the application of engine brake and service brake combination based on test results. A model of brake temperature rise for heavy duty vehicles running on long downhill sections was also constructed. For different braking modes, gear positions, speed and downhill slopes, brake temperature rising to 250°C was used as the index. Then simulation of brake temperature rise and downhill distance was researched. Simulation results illustrate that the combined braking of low gear and high speed should be adopted for heavy duty vehicles running on long downhill sections.

An improved model on forecasting temperature rise of high-speed angular contact ball bearings considering structural constraints

2018 ◽  
Vol 70 (1) ◽  
pp. 15-22 ◽  
Author(s):  
De-xing Zheng ◽  
Weifang Chen ◽  
Miaomiao Li
Keyword(s):  
Heat Generation ◽  
Temperature Rise ◽  
High Speed ◽  
Structural Constraints ◽  
Ball Bearings ◽  
Content Type ◽  
Grid Model ◽  
Simulation Results ◽  
Operation Parameters ◽  
Improved Model

Purpose Thermal performances are key factors impacting the operation of angular contact ball bearings. Heat generation and transfer about angular contact ball bearings, however, have not been addressed thoroughly. So far, most researchers only considered the convection effect between bearing housings and air, whereas the cooling/lubrication operation parameters and configuration effect were not taken into account when analyzing the thermal behaviors of bearings. This paper aims to analyze the structural constraints of high-speed spindle, structural features of bearing, heat conduction and convection to study the heat generation and transfer of high-speed angular contact ball bearings. Design/methodology/approach Based on the generalized Ohm’s law, the thermal grid model of angular contact ball bearing of high-speed spindle was first established. Next Gauss–Seidel method was used to solve the equations group by Matlab, and the nodes temperature was calculated. Finally, the bearing temperature rise was tested, and the comparative analysis was made with the simulation results. Findings The results indicate that the simulation results of bearing temperature rise for the proposed model are in better agreement with the test values. So, the thermal grid model established is verified. Originality/value This paper shows an improved model on forecasting temperature rise of high-speed angular contact ball bearings. In modeling, the cooling/lubrication operation parameters and structural constraints are integrated. As a result, the bearing temperature variation can be forecasted more accurately, which may be beneficial to improve bearing operating accuracy and bearing service life.

scholarly journals An Overview of Heavy Trucks/Buses Braking Performance

1991 ◽  
Vol 8 (1) ◽  
Author(s):  
Richard M. Ziernicki
Keyword(s):  
Statistical Data ◽  
Vehicle Speed ◽  
Test Results ◽  
Heavy Duty ◽  
Braking Performance ◽  
Emergency Braking ◽  
Heavy Trucks ◽  
Brake Performance ◽  
Drag Factor ◽  
Heavy Duty Vehicles

The writer discusses the performance of heavy duty vehicles during emergency braking. The paper reviews statistical data related to the trucking accidents, and discusses brake performance, tires, and the stopping ability of heavy duty vehicles. Relationships between drag factor, coefficient of friction, vehicle speed, type of tire, road surface, brake design, and brake temperature are discussed. Some of the test results performed on heavy trucks are presented. The discussion is general in order to make the presentation useful both to practicing reconstruction specialists, and to attorneys.

Thermal Analysis and Test for a High Speed PM Machine for Fan Application

2011 ◽  
Vol 383-390 ◽  
pp. 4727-4734 ◽  
Author(s):  
Ji Qiang Wang ◽  
Feng Xiang Wang
Keyword(s):  
Thermal Analysis ◽  
Temperature Rise ◽  
Power Loss ◽  
High Speed ◽  
Heat Dissipation ◽  
Machine Design ◽  
Test Results ◽  
Power Losses ◽  
Running Speed ◽  
High Speed Machine

For a give air flux, the higher speed the fanner is running, the smaller the fanner’s size is. It is also well known that for a given power, the higher the machine’s running speed, the smaller the machine’s size has. If the fanner is geared to a high speed machine directly, the fan set’s volume will be sharply decreased. However, the heat dissipation of the high speed machine becomes a serious problem also due to the small size and high power loss density. Therefore, how to estimate accurately the power losses and temperature rise is a key issue for the high speed machine design. In this paper, the power losses and temperature of high speed PM machine for a fanner application are thoroughly investigated. And the test results of a prototype fan set partly shown the validity of the calculation method.

Study on Reliability Test Method of Heavy Duty Vehicle Based on Proving Ground

2012 ◽  
Vol 614-615 ◽  
pp. 460-463
Author(s):  
Yu Zhuo Men ◽  
Hai Bo Yu ◽  
Xin Pan
Keyword(s):  
Load Distribution ◽  
Correlation Equation ◽  
Test Method ◽  
Reliability Test ◽  
Test Results ◽  
Heavy Duty ◽  
Test Specifications ◽  
Heavy Duty Vehicle ◽  
Load Carrying ◽  
Cumulative Fatigue Damage

A new method for correlation test was presented to study the reliability of a heavy duty vehicle, and the method can combine the real customer usage with the enhancement test on proving ground, and avoid the test blindness. Aiming at the data that were tested on the typical pavements of the customer and enhancement roads of proving ground, the rain-flow counting method was used to obtain the load distribution matrixes , according to the correlation equation, the cumulative fatigue damage and loading spectrums of the 90% customer and proving ground were optimized and calculated. Through the correlation analysis, the pavements enhancement coefficient and the reliability test specifications were obtained. The test results indicate that the new specifications can predict the potential failures of the load carrying structures quickly, shorten the test cycles.

scholarly journals Experimental Determination of the Performances during the Cold Start-Up of an Air Compressor Unit for Electric and Electrified Heavy-Duty Vehicles

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3664
Author(s):  
Gianluca Valenti ◽  
Stefano Murgia ◽  
Ida Costanzo ◽  
Matteo Scarnera ◽  
Francesco Battistella
Keyword(s):  
Volume Flow Rate ◽  
Cold Start ◽  
Input Power ◽  
Compressed Air ◽  
Compressor Unit ◽  
Heavy Duty ◽  
Air Compressor ◽  
Start Up ◽  
Heavy Duty Vehicle ◽  
Heavy Duty Vehicles

Compressed air is crucial on an electric or electrified heavy-duty vehicle. The objective of this work was to experimentally determine the performance parameters of the first prototype of an electric-driven sliding-vane air compressor, specifically designed for electric and electrified heavy-duty vehicles, during the transient conditions of cold start-ups. The transient was analyzed for different thermostatic temperatures: 0 °C, −10 °C, −20 °C, and −30 °C. The air compressor unit was placed in a climatic chamber and connected to the electric grid, the water-cooling loop, and the compressed air measuring and controlling rig. The required start-up time was greater the lower the thermostatic temperature, ranging from 30 min at 0 °C to 221 min at −30 °C and depending largely on the volume of the lubricant oil filled initially. The volume flow rate of the compressed air was lower than nominal at the beginning, but it showed a step increase well beyond nominal when the oil reached 50 °C and then decreased gently towards nominal, while the input power kept steady at nominal after a short initial peak. These facts must be considered when estimating the time and the energy required by the air compressor unit to fill up the compressed air tanks of the vehicles.

Economic Incentives to Mitigate Impacts of State Low-Emission Vehicle Standard for Heavy-Duty Vehicles

1996 ◽  
Vol 1520 (1) ◽  
pp. 63-70
Author(s):  
Thomas Kornfield ◽  
Jonathan Skolnik
Keyword(s):  
Economic Incentive ◽  
Economic Incentives ◽  
The State ◽  
Heavy Duty ◽  
Emission Standards ◽  
Heavy Duty Vehicle ◽  
Low Emission ◽  
Heavy Duty Vehicles

Economic incentive concepts that might reduce the likelihood that heavy-duty vehicle (HDV) operators will move their base operations out of California as a result of potential low-emission standards for HDVs based in the state are examined. In particular, 11 economic incentives that fall into the categories of rebates, taxes and fees, loans, and trading measures are examined. The results support the adoption of a fee-bate system under which registration fees would be based on the emission contributions of HDVs. Such a system could be applied to instate and out-of-state HDVs, thereby eliminating the incentive for operators to relocate outside California while encouraging the purchase and use of low-emission HDVs.

BENCHMARK RESULTS FOR HIGH-SPEED 4-BIT ACCUMULATORS IMPLEMENTED IN INDIUM PHOSPHIDE DHBT TECHNOLOGY

2004 ◽  
Vol 14 (03) ◽  
pp. 646-651 ◽  
Author(s):  
STEVEN EUGENE TURNER ◽  
DAVID E. KOTECKI
Keyword(s):  
Indium Phosphide ◽  
Power Consumption ◽  
High Speed ◽  
Large Scale ◽  
Supply Voltage ◽  
Power Reduction ◽  
Test Results ◽  
Clock Frequency ◽  
Speed Performance ◽  
Simulation Results

High-speed accumulators are frequently used as a benchmark of the high-speed performance and ability to yield large scale circuits in InP double hetereojunction bipolar (DHBT) processes. In previous work, we reported test results of an InP DHBT 4-bit accumulator with 624 transistors operating at 41 GHz clock frequency with a power consumption of 4.1W. In this work, we report on modifications that allow the circuit to operate at a lower supply voltage and a corresponding lower power consumption. Simulation results for this modification indicate that a 16% power reduction can be obtained, while maintaining a high-speed operating frequency of 40 GHz.

Modelling the longitudinal braking dynamics for heavy-duty vehicles

2021 ◽  
pp. 095440702110045
Author(s):  
İbrahim Can Güleryüz ◽  
Özgün Başer
Keyword(s):  
Response Time ◽  
System Model ◽  
Pneumatic System ◽  
Brake System ◽  
System Response ◽  
Heavy Duty ◽  
Matlab Simulink ◽  
Time Prediction ◽  
Heavy Duty Vehicle ◽  
Heavy Duty Vehicles

This paper establishes a reliable heavy-duty braking system model that can be used for response time prediction and for vehicle braking calculations regarding the legislative requirements. For the response time prediction, a pneumatic system model of a heavy-duty vehicle is constructed by Matlab Simulink in consideration of service brake layout. To ensure the accuracy of system parameters related with pneumatic system response time experiments are conducted on two different 4 × 4 heavy-duty vehicles. The numerically calculated response time results are validated with experimental data. To improve the response time of the vehicle, design modifications are conducted on the pneumatic brake system properties. To check the compliance of the pneumatic brake system design with legislative requirements of UN Regulation 13, heavy-duty vehicle brake system (HVBS) model is developed by using Matlab Simulink. HVBS model is composed of longitudinal vehicle and wheel dynamics, Magic Formula tyre model, wheel slip and the experimentally verified heavy-duty pneumatic system model. The braking performance analyses are conducted by using HVBS model to compare the design alternatives in accordance with the legal requirements in terms of service braking and secondary braking conditions.

Research on Air Deflector Optimal Design and Matching for Heavy-Duty Vehicle Based on Design of Experiment Technology

2013 ◽  
Vol 404 ◽  
pp. 188-193
Author(s):  
Jing Chen ◽  
Tao Song ◽  
Deng Feng Wang
Keyword(s):  
Optimal Design ◽  
Wind Tunnel ◽  
Drag Reduction ◽  
Wind Tunnel Test ◽  
Cfd Model ◽  
Heavy Duty ◽  
Cfd Simulations ◽  
Heavy Duty Vehicle ◽  
Fluent Software ◽  
Simulation Results

The drag reduction characteristic of air deflector of a heavy-duty vehicle is examined through CFD simulations and wind tunnel test in this paper. The CFD model of the truck is built using the FLUENT software and the simulation results are compared with the wind tunnel test data to verify the accuracy of simulation model. An air deflector is designed for this truck, A design of experiments approach was chosen as an efficient technique to optimize the design parameter and match with the truck to obtain the optimal drag reduction performance.

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