A Regenerative Hydraulically Assisted Turbocharger System Model

Author(s):  
Tao Zeng ◽  
Devesh Upadhyay ◽  
Guoming Zhu

A regenerative hydraulically assisted turbocharging system is introduced. A systematic modeling approach for the engine air-path influenced under the influence of the RHAT system is discussed. The proposed modeling approach adopted seeks to reduce model complexity by introducing simple parametric relationships between corrected performance measures and allows smooth extrapolation beyond available hydraulic turbine and pump maps. A lumped parameter model of the hydraulic system is presented. Model validation results are presented for an FTP-75 cycle.

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Li Chenggong ◽  
Jiao Zongxia

This paper presents the fundamental approaches of modeling thermal-hydraulic component briefly. A set of lumped parameter mathematical models is developed, which are based on conservation of mass and energy. Subsequently, the connection rule for basic thermal-hydraulic components and the method to automatically generate the complete thermal-hydraulic system model are put forward. The integration methods for solving the cross-coupling thermal-hydraulic equations are also discussed for a position-controlled thermal-hydraulic system. Simulation results show the interaction between pressure and temperature. The simplified representations of thermal-hydraulic differential equations are also proposed in this paper, which can reduce simulation time. The validity of the simplified representations is judged by simulation.


2014 ◽  
Vol 6 (4) ◽  
Author(s):  
William S. Rone ◽  
Pinhas Ben-Tzvi

This paper presents a novel modeling approach for the mechanics of multisegment, rod-driven continuum robots. This modeling approach utilizes a high-fidelity lumped parameter model that captures the variation in curvature along the robot while simultaneously defined by a discrete set of variables and utilizes the principle of virtual power to formulate the statics and dynamics of the continuum robot as a set of algebraic equations for the static model and as a set of coupled ordinary differential equations (ODEs) in time for the dynamic model. The actuation loading on the robot by the actuation rods is formulated based on the calculation of contact forces that result in rod equilibrium. Numerical optimization calculates the magnitudes of these forces, and an iterative solver simultaneously estimates the robot's friction and contact forces. In addition, modeling considerations including variable elastic loading among segments and mutual segment loading due to rods terminating at different disks are presented. The resulting static and dynamic models have been compared to dynamic finite element analyses and experimental results to validate their accuracy.


2020 ◽  
Vol 28 (02) ◽  
pp. 2050012
Author(s):  
Daniel Gert Nielsen ◽  
Peter Risby Andersen ◽  
Jakob Søndergaard Jensen ◽  
Finn Thomas Agerkvist

Finite element methods are progressively being utilized to assist in the continuous development of loudspeakers. The core of this paper is the method of lumping certain parts of the finite element model, creating a significant reduction in the model complexity that allows for e.g. faster structural optimization. This is illustrated in the paper with a loudspeaker example where the electromagnetic parts are lumped as well as the spider. It is shown that the simplified model still matches the complex response of the full FE model at very high frequencies.


2016 ◽  
Vol 17 (03) ◽  
pp. 1750056 ◽  
Author(s):  
S. V. FROLOV ◽  
S. V. SINDEEV ◽  
V. A. LISCHOUK ◽  
D. SH. GAZIZOVA ◽  
D. LIEPSCH ◽  
...  

Mathematical modeling of cardiovascular system provides an ability to study hemodynamics and to predict the results of treatment based on individual anatomical and physiological data of patients. However, the presently developed models of cardiovascular system have a limitation on use in clinical practice due to their physical and computational complexities. The aim of this study is to derive a lumped parameter model of cardiovascular system with pulsating heart in which all parameters have a physically based quantitative value and can be identified using clinical methods. For development of a cardiovascular system model the chamber analog was used which describes whole cardiovascular system as a set of elastic chambers. The proposed model consists of systemic and pulmonary circulation, four-chamber heart and four valves. The description of heart is based on a four-element representation of a cardiac muscle. The reverse blood flow via valves is considered. The accuracy of the derived model was evaluated by comparing the data of numerical simulation with experimental data. The limitations of the model were discussed as well as possible applications of the model were suggested. The proposed lumped parameter model can be used to support clinicians in their decisions in treating cardiovascular disorders.


2020 ◽  
Vol 48 (12) ◽  
pp. 2870-2886
Author(s):  
Mehran Mirramezani ◽  
Shawn C. Shadden

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