Simulation of Multi-body Systems Using Multi-bond Graphs

Abstract One commonly used pump in the petroleum sector is the Progressing Cavity Pump (PCP). The PCP is a type of positive displacement pump that is used as an artificial lifting system which consists of a helical rotor and elastomeric stator. A mathematical solution to a PCP system model requires that we solve a partial differential equation system. The solution is inherently complex and requires considerable computational time. This paper uses the bond graph formalism, which is based on energy and information flow, to implement a model of a PCP system. Its purpose is to predict the dynamic response of the PCP system when it is subjected to a specific reservoir condition. Specifically focusing on the rod string, the torsional effects are captured by a lumped segment approximation. The software 20-Sim© was used to simulate a realistic PCP system application scenario. The model presented in this paper is able to determine the prime mover, rod string, and other component requirements. This paper shows that the multi-body lumped segment model is a useful way to simulate the rod string performance. The bond graph is effective at modeling the PCP system which contains elements from different energy domains.

Download Full-text

FLOW VISUALIZATION AROUND MESOSCALE SOLID PARTICLE WITHIN A MOVING DROPLET USING MULTI-BODY DISSIPATIVE PARTICLE DYNAMICS

10.1615/tfec2019.fnd.028436 ◽

2019 ◽

Author(s):

Anupam Mishra ◽

Ahmed A. Hemeda ◽

Mohsen Torabi ◽

Ting Liu ◽

James Palko ◽

...

Keyword(s):

Flow Visualization ◽

Solid Particle ◽

Dissipative Particle Dynamics ◽

Particle Dynamics ◽

Multi Body

Download Full-text

Eigenvalue Spectra and Bounds for Certain Classes of Dynamic Systems having Tree Bond Graphs

10.23919/acc.1984.4788403 ◽

1984 ◽

Cited By ~ 1

Author(s):

A. Zeid ◽

R. Rosenberg

Keyword(s):

Dynamic Systems ◽

Bond Graphs

Download Full-text

Stress fields in granular material and implications for performance of robot locomotion over granular media

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v8i1.1530 ◽

2015 ◽

Vol 8 (1) ◽

pp. 2005-2009

Author(s):

Diandong Ren ◽

Lance M. Leslie ◽

Congbin Fu

Keyword(s):

Mechanical Properties ◽

Granular Material ◽

Granular Media ◽

Rotation Frequency ◽

Legged Locomotion ◽

Working Environment ◽

Navier Stokes ◽

Maximum Speed ◽

Sigmoid Curve ◽

Multi Body

Â Legged locomotion of robots has advantages in reducing payload in contexts such as travel over deserts or in planet surfaces. A recent study (Li et al. 2013) partially addresses this issue by examining legged locomotion over granular media (GM). However, they miss one extremely significant fact. When the robotâ€™s wheels (legs) run over GM, the granules are set into motion. Hence, unlike the study of Li et al. (2013), the viscosity of the GM must be included to simulate the kinematic energy loss in striking and passing through the GM. Here the locomotion in their experiments is re-examined using an advanced Navier-Stokes framework with a parameterized granular viscosity. It is found that the performance efficiency of a robot, measured by the maximum speed attainable, follows a six-parameter sigmoid curve when plotted against rotating frequency. A correct scaling for the turning point of the sigmoid curve involves the footprint size, rotation frequency and weight of the robot. Our proposed granular response to a load, or the â€˜influencing domainâ€™ concept points out that there is no hydrostatic balance within granular material. The balance is a synergic action of multi-body solids. A solid (of whatever density) may stay in equilibrium at an arbitrary depth inside the GM. It is shown that there exists only a minimum set-in depth and there is no maximum or optimal depth. The set-in depth of a moving robot is a combination of its weight, footprint, thrusting/stroking frequency, surface property of the legs against GM with which it has direct contact, and internal mechanical properties of the GM. If the vehicleâ€™s working environment is known, the wheel-granular interaction and the granular mechanical properties can be grouped together. The unitless combination of the other three can form invariants to scale the performance of various designs of wheels/legs. Wider wheel/leg widths increase the maximum achievable speed if all other parameters are unchanged.

Download Full-text