Active Torsion Bar Body Roll Minimization System: Design and Testing

2003 ◽  
Author(s):  
David Cimba ◽  
Kyle Gilbert ◽  
John Wagner
Keyword(s):  
Cost Effective ◽  
Vehicle Body ◽  
Design Parameters ◽  
Test Environment ◽  
Component Design ◽  
Body Roll ◽  
And Performance ◽  
Emergency Scenarios ◽  
The Impact ◽  
Torsion Bar

Sport utility and light-duty commercial vehicles exhibit a higher propensity for rollover during aggressive driving maneuvers, emergency scenarios, and degraded environmental conditions. A variety of strategies have been proposed to reduce vehicle body roll including active suspensions, comprehensive yaw stability systems, and active torsion bars. The active torsion bar systems have recently gained popularity due to their cost effective design and adaptability to existing chassis systems. However, the development of new control algorithms, design of subsystem components, and the evaluation of parameter sensitivity via testing a full scale vehicle is not always practical due to cost and safety concerns. Thus, a modular simulation tool and bench top testing environment is required to facilitate design and performance studies. In this paper, a series of mathematical models will be introduced to describe the vehicle dynamics and the roll prevention system. Representative numerical results are discussed to investigate a vehicle’s transient response with and without an active torsion bar system, as well as the impact of torsion bar and hydraulic component design parameters. Finally, a hardware in-the-loop test environment will be presented.

Analytic Optimization of Cost Effective Thermoelectric Generation on Top of Rankine Cycle

2013 ◽  
Author(s):  
Kazuaki Yazawa ◽  
Yee Rui Koh ◽  
Ali Shakouri
Keyword(s):  
Steam Turbine ◽  
Fuel Efficiency ◽  
Cost Effective ◽  
Rankine Cycle ◽  
Energy Conversion Efficiency ◽  
Design Parameters ◽  
Steam Temperature ◽  
Combined System ◽  
Fuel Consumption Rate ◽  
The Impact

Thermoelectric (TE) generators have a potential advantage of the wide applicable temperature range by a proper selection of materials. In contrast, a steam turbine (ST) as a Rankine cycle thermodynamic generator is limited up to more or less 630 °C for the heat source. Unlike typical waste energy recovery systems, we propose a combined system placing a TE generator on top of a ST Rankine cycle generator. This system produces an additional power from the same energy source comparing to a stand-alone steam turbine system. Fuel efficiency is essential both for the economic efficiency and the ecological friendliness, especially for the global warming concern on the carbon dioxide (CO2) emission. We report our study of the overall performance of the combined system with primarily focusing on the design parameters of thermoelectric generators. The steam temperature connecting two individual generators gives a trade-off in the system design. Too much lower the temperature reduces the ST performance and too much higher the temperature reduces the temperature difference across the TE generator hence reduces the TE performance. Based on the analytic modeling, the optimum steam temperature to be designed is found near at the maximum power design of TE generator. This optimum point changes depending on the hours-of-operation. It is because the energy conversion efficiency directly connects to the fuel consumption rate. As the result, physical upper-limit temperature of steam for ST appeared to provide the best fuel economy. We also investigated the impact of improving the figure-of-merit (ZT) of TE materials. As like generic TE engines, reduction of thermal conductivity is the most influential parameter for improvement. We also discuss the cost-performance. The combined system provides the payback per power output at the initial and also provides the significantly better energy economy [$/KWh].

Numerical Investigation of the Effect of Diffuser and Volute Design Parameters on the Performance of a Centrifugal Compressor Stage

2016 ◽  
Author(s):  
Lei Yu ◽  
William T. Cousins ◽  
Feng Shen ◽  
Georgi Kalitzin ◽  
Vishnu Sishtla ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Gas Flow ◽  
Pressure Rise ◽  
Design Parameters ◽  
Compressor Stage ◽  
Flow Distortion ◽  
Cross Sectional ◽  
Centrifugal Stage ◽  
And Performance ◽  
The Impact

In this effort, 3D CFD simulations are carried out for real gas flow in a refrigeration centrifugal compressor. Both commercial and the in-house CFD codes are used for steady and unsteady simulations, respectively. The impact on the compressor performance with various volute designs and diffuser modifications are investigated with steady simulations and the analysis is focused on both the diffuser and the volute loss, in addition to the flow distortion at impeller exit. The influence of the tongue, scroll diffusion ratio, diffuser length, and cross sectional area distribution is examined to determine the impact on size and performance. The comparisons of total pressure loss, static pressure recovery, through flow velocity, and the secondary flow patterns for different volute designs show that the performance of the centrifugal compressor depends upon how well the scroll portion of the volute collects the flow from the impeller and achieves the required pressure rise with minimum flow losses in the overall diffusion process. Finally, the best design is selected based on compressor stage pressure rise and peak efficiency improvement. An unsteady simulation of the full wheel compressor stage was carried out to further examine the interaction of impeller, diffuser and the volute. The unsteady flow interactions are shown to have a major impact on the performance of the centrifugal stage.

Structure Analysis and Performance Simulation on the Walking Mechanism of the Transportation Machine Providing Disaster Relief

2011 ◽  
Vol 183-185 ◽  
pp. 2237-2241
Author(s):  
Hui Wang ◽  
Yan Ma ◽  
Chang Qing Ren ◽  
Ning Li
Keyword(s):  
Disaster Relief ◽  
Impact Factors ◽  
Design Parameters ◽  
Theoretical Derivation ◽  
Component Size ◽  
Development And Utilization ◽  
The New Period ◽  
And Performance ◽  
Walking Mechanism ◽  
The Impact

It makes a brief description of the transportation machine providing disaster relief. The paper makes a deep analysis and founds a scheme on the walking mechanism of the transportation machine sending relief to a disaster area, illustrates the relationship among the mechanism structure, component size, tracks and kinematic parameters of the foot. It makes an experimental prototype design which through the analysis before, embeds the scheme into the design parameters, and conducts an actual verification about the results of theoretical derivation. The results proved the feasibility of the design, and reflected the impact factors. It will lay the theoretical foundation for the walking mechanism’s design and research of the transportation machine providing disaster relief, and will be in favor of the development and utilization of the transportation machine providing disaster relief in the new period.

On the vibration analysis of off-road vehicles: Influence of terrain deformation and irregularity

2018 ◽  
Vol 24 (22) ◽  
pp. 5418-5436 ◽  
Author(s):  
Giulio Reina ◽  
Antonio Leanza ◽  
Arcangelo Messina
Keyword(s):  
Performance Optimization ◽  
Operating Conditions ◽  
Vehicle Body ◽  
Surface Irregularity ◽  
Parameter Study ◽  
Road Vehicles ◽  
Wheel Rolling ◽  
And Performance ◽  
Underlying Mechanisms ◽  
The Impact

Surface irregularity acts as a major excitation source in off-road driving that induces vibration of the vehicle body through the tire assembly and the suspension system. When adding ground deformability, this excitation is modulated by the soil properties and operating conditions. The underlying mechanisms that govern ground behavior can be explained and modeled drawing on Terramechanics. Based on this theory, a comprehensive quarter-car model of off-road vehicle is presented that takes into account tire/soil interaction. The model can handle the general case of compliant wheel rolling on compliant ground and it allows ride and road holding performance to be evaluated in the time and frequency domain. An extensive set of simulation tests is included to assess the impact of various surface roughness and ground deformability through a parameter study, showing the potential of the proposed model to describe the behavior of off-road vehicles for design and performance optimization purposes.

Model Predictive Engine Speed Control for Transmissions With Dog Clutches

2016 ◽  
Author(s):  
Qilun Zhu ◽  
Robert Prucka ◽  
Michael Prucka ◽  
Hussein Dourra
Keyword(s):  
Engine Speed ◽  
Speed Control ◽  
Cost Effective ◽  
Combustion Stability ◽  
Design Parameters ◽  
Shift Quality ◽  
Engine Model ◽  
Prediction Horizon ◽  
Indicated Mean Effective Pressure ◽  
The Impact

The need for cost-effective fuel economy improvements has driven the introduction of automatic transmissions with an increasing number of gear ratios. Incorporation of interlocking dog clutches in these transmissions decreases package space and increases efficiency, as compared to conventional dry or wet clutches. Unlike friction based clutches, interlocking dog clutches require very precise rotational speed matching prior to engagement. Precise engine speed control is therefore critical to maintaining high shift quality. This research focuses on controlling the engine speed during a gearshift period by manipulating throttle position and combustion phasing. Model predictive control (MPC) is advantageous in this application since the speed profile of a future prediction horizon is known with relatively high confidence. The MPC can find the optimal control actions to achieve the designated speed target without invoking unnecessary actuator manipulation and violating hardware and combustion constraints. This research utilizes linear parameter varying (LPV) MPC to control the engine speed during the gearshift period. Combustion stability constraints are considered with a control oriented covariance of indicated mean effective pressure model (COV of IMEP). The proposed MPC engine speed controller is validated with a high-fidelity 0-dimensional engine model with crank angle resolution. Four case studies, based on simulation, investigate the impact of different MPC design parameters. They also demonstrate that the proposed MPC engine controller successfully achieves the speed reference tracking objective while considering combustion variation constraints.

HRSG Fleet Integrity Management: Lessons Learned From the Field

2020 ◽  
Author(s):  
Andreas Fabricius ◽  
James Malloy ◽  
Mark Taylor ◽  
Peter Jackson ◽  
David Moelling
Keyword(s):  
Asset Management ◽  
Corporate Strategy ◽  
Management Strategies ◽  
Cost Effective ◽  
Operating Mode ◽  
Field Work ◽  
Lessons Learned ◽  
Management Actions ◽  
And Performance ◽  
The Impact

Abstract This paper presents key lessons learned from hundreds of field missions for assessing the condition of HRSGs at sites around the world. These involved field inspections, root cause of failure analyses and performance assessments on HRSGs of nearly every design, fuel type and operating mode. Statistics on degradation and failure risk areas are presented. Analysis techniques used in both preparing for field work and in assessing field examination results are also discussed. Trends in the evolution of the principal damage mechanisms over the years are examined, and predictions of future problem areas are considered with a view to guiding asset management actions. The impact on HRSG integrity of changes in unit designs, such as the move to flexible operation in response to the increasing contribution from renewables, is also assessed, and likely future trends are outlined. The use of qualitative and quantitative risk-based methods is also discussed and compared to the use of condition-based inspection methods as a basis for a fleet wide management strategy. A case study including a large IPP with several generating assets in its portfolio is presented and the most cost-effective method with respect to current corporate strategy is discussed. Recommendations for fleet management strategies are made.

The Effects of Tire Properties and Their Interaction with the Ground and Suspension on Vehicle Dynamic Behavior — A Finite Element Approach

1999 ◽  
Vol 27 (4) ◽  
pp. 227-249 ◽  
Author(s):  
Y. Zhang ◽  
C. Hazard
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Practical Method ◽  
Suspension System ◽  
Vehicle Body ◽  
Vehicle Dynamic ◽  
Analysis Method ◽  
Element Analysis ◽  
Body Roll ◽  
The Impact

Abstract The effects of tire properties and their interaction with the ground and the suspension system on vehicle dynamic behavior was studied using a newly developed finite element analysis method. This analysis method used the explicit nonlinear dynamic code LS-DYNA as a solver and contained finite element models for both the vehicle body structure and subsystems like chassis/suspension. The case presented in this paper is curb impact. Different tire properties such as tire/wheel assembly mass, tire stiffness, tire inflation pressure, tire size, etc., as well as different curb heights, were used with the same vehicle body and suspension system. Simulation results of the impact forces, wheel center jumps, and vehicle body roll/pitch angles at impact are compared for different parameters of the tires and the curb. The analyses presented in this paper provided an accurate and practical method for tire and vehicle dynamics analysis.

Investigation of active torsion bar actuator configurations to reduce vehicle body roll

2006 ◽  
Vol 44 (9) ◽  
pp. 719-736 ◽  
Author(s):  
David Cimba ◽  
John Wagner ◽  
Abhijit Baviskar
Keyword(s):  
Vehicle Body ◽  
Body Roll ◽  
Torsion Bar

The Impact of Suspension Stiffness Parameters on the Curve through Performance of Straddle Type Monorail Vehicle Based on Sensitivity Analysis

2013 ◽  
Vol 470 ◽  
pp. 563-566
Author(s):  
Zi Xue Du ◽  
Zhi Hua Liang ◽  
Xiao Xia Wen
Keyword(s):  
Sensitivity Analysis ◽  
Vehicle Body ◽  
Vertical Force ◽  
Wear Performance ◽  
Evaluation Indexes ◽  
Body Roll ◽  
Overturning Stability ◽  
Suspension Stiffness ◽  
Tire Forces ◽  
The Impact

The curve through performance of straddle type monorail vehicle include performance-oriented, preventing derailment stability, preventing vehicle overturning stability, tire wear performance, which are evaluated by oriented torque, the minimum vertical force of horizontal wheels, vehicle body roll angle, overturning coefficient, the sum of tire forces scalar. With the virtual simulation model in ADAMS, this paper analyzes the impact of the monorail vehicle suspension stiffness parameters on the evaluation indexes by sensitivity analysis.

scholarly journals The influence of vehicle body roll angle on the motion stability and maneuverability of the vehicle

2017 ◽  
Vol 168 (1) ◽  
pp. 133-139
Author(s):  
Krzysztof PARCZEWSKI ◽  
Henryk WNĘK
Keyword(s):  
Dynamic Change ◽  
Steady Motion ◽  
Roll Angle ◽  
Vehicle Body ◽  
Sideslip Angle ◽  
Lateral Forces ◽  
Camber Angle ◽  
Body Roll ◽  
Vehicle Motion ◽  
The Impact

The article discusses the impact of design solutions of vehicle suspensions into angles of body roll. It was shown which type of suspensions is better from this point of view. There were examined the dependence of the suspensions parameters on the vehicle body roll angle. The influence of camber angle on the force transmitted to the tire contact with the road surface was analysed. The lateral forces were measured on the test stand. There was tested dependency of lateral forces from the sideslip angle for different angles of camber. Was analysed change of lateral forces generated by camber angle on the vehicle which was made on a scale ~ 1:5 during tests carried out on the testing track. For this purpose, two tests have been selected: first one allowing the measurement in steady motion conditions, the second one with dynamic change of direction of vehicle motion. The graphs show the effect of camber angles on the controllability and stability of the vehicle motion.

Sign in / Sign up

Export Citation Format

Share Document