scholarly journals Suspended Decoupler: A New Design of Hydraulic Engine Mount

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
J. Christopherson ◽  
M. Mahinfalah ◽  
Reza N. Jazar
Keyword(s):  
Steady State ◽  
Transient Response ◽  
Equations Of Motion ◽  
State Behavior ◽  
Engine Mounts ◽  
Nonlinear Finite Elements ◽  
Lumped Parameter ◽  
Start Up ◽  
Engine Mount ◽  
Static Conditions

Because of the density mismatch between the decoupler and surrounding fluid, the decoupler of all hydraulic engine mounts (HEM) might float, sink, or stick to the cage bounds, assuming static conditions. The problem appears in the transient response of a bottomed-up floating decoupler hydraulic engine mount. To overcome the bottomed-up problem, a suspended decoupler design for improved decoupler control is introduced. The new design does not noticeably affect the mechanism's steady-state behavior, but improves start-up and transient response. Additionally, the decoupler mechanism is incorporated into a smaller, lighter, yet more tunable and hence more effective hydraulic mount design. The steady-state response of a dimensionless model of the mount is examined utilizing the averaging perturbation method applied to a set of second-order nonlinear ordinary differential equations. It is shown that the frequency responses of the floating and suspended decoupled designs are similar and functional. To have a more realistic modeling, utilizing nonlinear finite elements in conjunction with a lumped parameter modeling approach, we evaluate the nonlinear resorting characteristics of the components and implement them in the equations of motion.

Suspended Decoupler Design of Hydraulic Engine Mount

2011 ◽  
Author(s):  
Reza N. Jazar ◽  
M. Mahinfalah ◽  
J. Christopherson
Keyword(s):  
Steady State ◽  
Transient Response ◽  
Equations Of Motion ◽  
State Behavior ◽  
State Response ◽  
Nonlinear Finite Elements ◽  
Lumped Parameter ◽  
Start Up ◽  
Engine Mount ◽  
Static Conditions

A known problem in classical hydraulic engine mount is that because of the density mismatch between the decoupler and surrounding fluid, the decoupler might float, or stick to the cage bounds, assuming static conditions. The problem appears in the transient response of a bottomed up floating decoupler hydraulic engine mount. To overcome the bottomed up problem, a suspended decoupler design for improved decoupler control is introduced. The new design does not noticeably effect the mechanisms steady state behavior, but improves start up and transient response. Additionally, the decoupler mechanism is incorporated into a smaller, lighter, yet more tunable and hence more effective hydraulic mount design. Ususally the elastomechanical components in a hydraulic engine mount are assumed lumped and linear. To have a more realistic modeling, utilizing nonlinear finite elements in conjunction with a lumped parameter modeling approach, we evaluate the resorting characteristics of the components and implement them in the equations of motion. The steady state response of a dimensionless model of the mount is examined utilizing the averaging perturbation method applied to a set of second order nonlinear ordinary differential equations. It is shown that the frequency responses of the floating and suspended decoupled designs are similar and functional.

Development of a New Design Hydraulic Engine Mount

2005 ◽  
Author(s):  
G. Nakhaie Jazar ◽  
J. Christopherson
Keyword(s):  
Steady State ◽  
Nonlinear Model ◽  
State Behavior ◽  
Design Flexibility ◽  
Fluid Behavior ◽  
Start Up ◽  
Hysteretic Damping ◽  
Elastomeric Materials ◽  
Engine Mount ◽  
Steady State Behavior

In this paper a new design of the passive hydraulic engine mount is introduced. A means for improved decoupler control is introduced that does not noticeably affect the mechanisms steady state behavior, but improves start up and transient response. In addition, the decoupler mechanism is incorporated into a smaller, lighter, yet more tunable and hence more effective hydraulic mount design. The performance of the new hydraulic mount is discussed by means of a full nonlinear model. The increased design flexibility afforded by the redesigned support structure provides means by which to tune the engine mount to various engine support configurations. In addition, the proposed mount does not rely as heavily on hysteretic damping provided through elastomeric materials, which can be difficult to control, but more so on fluid behavior inside the engine mount; therefore, the damping of the system is much more tunable than previous hydraulic engine mount designs.

Simulation of Engine Vibration on Nonlinear Hydraulic Engine Mounts

2005 ◽  
Author(s):  
A. R. Ohadi ◽  
G. Maghsoodi
Keyword(s):  
Equations Of Motion ◽  
Low Frequency ◽  
Governing Equations ◽  
Engine Mounts ◽  
Engine Vibration ◽  
Engine Mount ◽  
Rotational Motions ◽  
The Time Domain ◽  
Nonlinear Equations Of Motion ◽  
Four Cylinders

In this paper, vibration behavior of engine on nonlinear hydraulic engine mount including inertia track and decoupler is studied. In this regard, after introducing the nonlinear factors of this mount (i.e. inertia and decoupler resistances in turbulent region), the vibration governing equations of engine on one hydraulic engine mount are solved and the effect of nonlinearity is investigated. In order to have a comparison between rubber and hydraulic engine mounts, a 6 degree of freedom four cylinders V-shaped engine under inertia and balancing masses forces and torques is considered. By solving the time domain nonlinear equations of motion of engine on three inclined mounts, translational and rotational motions of engines body are obtained for different engine speeds. Transmitted base forces are also determined for both types of engine mount. Comparison of rubber and hydraulic mounts indicates the efficiency of hydraulic one in low frequency region.

Periodic Motions of a Two-Body System Subjected to Repetitive Impact

1969 ◽  
Vol 91 (4) ◽  
pp. 931-938 ◽  
Author(s):  
David L. Sikarskie ◽  
Burton Paul
Keyword(s):  
Steady State ◽  
High Speed ◽  
Equations Of Motion ◽  
Point Of View ◽  
State Behavior ◽  
State Response ◽  
Stability Of Solution ◽  
Straightforward Method ◽  
Parametric Studies ◽  
Repetitive Impact

The dynamics of a widely used class of hammer impact machines are investigated on the basis of a two-degree-of-freedom idealization. The difficulty in the problem is due to the repetitive impact which introduces a nonlinearity in the system. It is the purpose of the analysis to develop a solution for the steady-state behavior of the system. There are several ways this can be done. One of the most efficient ways, from the point of view of ease of parametric studies of the system, is to convert the problem to a “boundary” value problem. With this technique, the system is governed by the equations of motion between impacts, and further satisfies additional conditions at the beginning and end of each impact cycle. Since the solution is obtained in only one cycle, it thus represents a straightforward method of studying the effect of various system parameters. A fundamental assumption in the analysis is that the steady-state response of the system has a period equal to the forcing period. This is verified for one set of parameters through the use of high-speed movies of an actual machine. There are several other interesting features in the analysis, including multivaluedness of the solution, allowable solution domain, and stability of solution, which have not been completely resolved to date.

Chaotic Behavior of Hydraulic Engine Mount

2006 ◽  
Author(s):  
J. Christopherson ◽  
G. Nakhaie Jazar ◽  
M. Mahinfalah
Keyword(s):  
Boundary Conditions ◽  
Chaotic Behavior ◽  
Hysteretic Behavior ◽  
Constitutive Relationship ◽  
Element Analysis ◽  
Engine Mounts ◽  
Fluid Behavior ◽  
Lumped Parameter ◽  
Engine Mount ◽  
Parameter Approach

The constitutive relationships of the rubber materials that act as the main spring of a hydraulic mount are nonlinear. In addition to material induced nonlinearity, further nonlinearities may be introduced by mount geometry, turbulent fluid behavior, boundary conditions, temperature, decoupler action, and hysteretic behavior. While all influence the behavior of the system only certain aspects are realistically considered using the lumped parameter approach employed in this research. The nonlinearities that are readily modeled by the lumped parameter approach constitute the geometry and constitutive relationship induced nonlinearity, including hysteretic behavior, noting that these properties all make an appearance in the load-deflection relationship for the mount and may be readily determined via experiment or flnite element analysis. In this paper we will shoe that under certain conditions, the nonlinearities involved in the hydraulic engine mounts can show a chaotic response.

A Simulation of a Supersonic Intake on a Hybrid Computer

1980 ◽  
Vol 31 (3) ◽  
pp. 197-220
Author(s):  
D.E. Colbourne
Keyword(s):  
Steady State ◽  
Mach Number ◽  
Dynamic Performance ◽  
Equations Of Motion ◽  
Two Dimensional ◽  
Frequency Responses ◽  
Lumped Parameter ◽  
Time Simulation ◽  
Hybrid Computer ◽  
High Mach

SummaryA simulation of the steady-state and dynamic performance of a supersonic powerplant intake is described. A lumped-parameter form of the equations of motion for a compressible fluid is developed. The resulting equations, together with steady-state characteristics, are used to model the performance of a two-dimensional supersonic intake. The model is implemented on the NGTE hybrid computer. The performance, both steady-state and transient, of the resulting real-time simulation has been investigated. Step and frequency responses at two high Mach number flight conditions have been examined and compared with test data. The favourable comparisons obtained demonstrate the validity of the chosen technique.

Closed-Form Transient Response of Distributed Damped Systems, Part II: Energy Formulation for Constrained and Combined Systems

1996 ◽  
Vol 63 (4) ◽  
pp. 1004-1010 ◽  
Author(s):  
Bingen Yang
Keyword(s):  
Closed Form ◽  
Transient Response ◽  
Differential Operators ◽  
Equations Of Motion ◽  
Closed Form Solution ◽  
Form Solution ◽  
Response Analysis ◽  
Lumped Parameter ◽  
Damped Systems ◽  
Energy Formulation

The transient response analysis presented in Part I is generalized for distributed damped systems which are viscoelastically constrained or combined with lumped parameter systems. An energy formulation is introduced to regain symmetry for the spatial differential operators, which is destroyed in the original equations of motion by the constraints, and the coupling of distributed and lumped elements. As a result, closed-form solution is systematically obtained in eigenfunction series.

Start Up and Transient Response to Power Input of a Capillary Assisted Thermosyphon for Shipboard Electronics Cooling

2010 ◽  
Author(s):  
V. Tudor ◽  
M. Cerza
Keyword(s):  
Steady State ◽  
Flat Plate ◽  
Transient Response ◽  
Flow Rate ◽  
Heat Input ◽  
Electric Propulsion ◽  
Electronics Cooling ◽  
Working Fluid ◽  
Cold Plate ◽  
Start Up

The future capabilities of naval ships will be directly related to the electronic components used in advanced radar systems, fire control systems, electric propulsion and even electric weapons. The next generation of naval warships will fall under the concept of an all electric ship, where turbines convert all the power produced by the engine into electricity. This electrical power can then be distributed given the ship’s mission and operating profile. The current need for advanced electronics cooling techniques is paramount since power dissipation levels are rapidly exceeding the capabilities of forced air convection cooling. This paper reports an experimental investigation of the start-up and transient response to heat load change of a capillary assisted thermosyphon (CAT) for the shipboard cooling of electronics components. The capillary assisted thermosyphon differs from a capillary pumped loop or loop heat pipe system in that the basic cooling-loop is based on a thermosyphon. The capillary assist comes from the fact that there is a wicking structure in the flat evaporator plate. The wicking structure allows uniformly spread of the working fluid across the flat plate evaporator in the areas under the heat sources as well as providing additional capillary pumping assist to the loop. A vertical flat plate, CAT evaporator was designed and tested under a fixed thermal sink temperature of 21°C. The condenser cold plate cooling water flow rate was fixed as 3.785 liters per minute (i.e. 1 gpm). The heat input varied from 250 to 1000W — evenly spread over the area of the evaporator. The CAT flat plate evaporator performed very well under this range of heat inputs, sink temperature, and cold plate flow rate. The main result obtained showed that the CAT loop reached steady state operation within 10 min. to 15 min. The average plate temperature did not exceed 70°C for the maximum heat input of 1000W. The CAT evaporator operating temperature increased with increasing heat input for all conditions tested and reached 60°C at 1000W. The continuous and stable operation of the CAT loop during start-up, steady-state and during transient/sudden heat input variations indicates that the CAT loop is a viable solution for high flux electronics components cooling.

Simulation of Engine Vibration on Nonlinear Hydraulic Engine Mounts

2007 ◽  
Vol 129 (4) ◽  
pp. 417-424 ◽  
Author(s):  
A. R. Ohadi ◽  
G. Maghsoodi
Keyword(s):  
Equations Of Motion ◽  
Low Frequency ◽  
Governing Equations ◽  
Engine Mounts ◽  
Engine Vibration ◽  
Engine Mount ◽  
Rotational Motions ◽  
The Time Domain ◽  
Nonlinear Equations Of Motion ◽  
Six Degree Of Freedom

In this paper, vibration behavior of engine on the nonlinear hydraulic engine mount, including inertia track and decoupler, is studied. In this regard, after introducing the nonlinear factors of this mount (i.e., inertia and decoupler resistances in turbulent region), the vibration governing equations of engine on one hydraulic engine mount are solved and the effect of nonlinearity is investigated. In order to have a comparison between the rubber and the hydraulic engine mounts, a six-degree-of-freedom four-cylinder V-shaped engine under shaking and balancing mass forces and torques is considered. By solving the time domain nonlinear equations of motion of the engine on three inclined mounts, translational and rotational motions of an engine body are obtained for different engine speeds. Transmitted base forces are also determined for both types of engine mount. Comparison of rubber and hydraulic mounts indicates the efficiency of a hydraulic one in the low-frequency region.

Stability of Motion of Elastic Planar Linkages With Application to Slider Crank Mechanism

1982 ◽  
Vol 104 (4) ◽  
pp. 698-703 ◽  
Author(s):  
I. G. Tadjbakhsh
Keyword(s):  
Steady State ◽  
Equations Of Motion ◽  
Steady State Solution ◽  
Critical Values ◽  
Length Ratio ◽  
Viscous Damping ◽  
Stability Of Motion ◽  
Start Up ◽  
Planar Linkages ◽  
Crank Mechanism

The problem of stability of motion of elastic planar linkages is considered in the context of the classical Euler-Bernoulli equations of motion. The case of slider-crank mechanism is considered in detail and the critical values of the dimensionless parameters measuring slenderness, speed, and length ratio which may cause instability are determined. The start-up and the steady-state solution of the mechanism without viscous damping and the effects of flexibility on piston force and efficiency is evaluated.

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