Kavlicoglu B.,Advanced Materials and Devices |
Gordaninejad F.,University of Nevada, Reno |
Wang X.,University of Nevada, Reno
Journal of Applied Mechanics, Transactions ASME
This study presents a new approach for flow analysis of magnetorheological (MR) fluids through channels with various surface topologies. Based on an experimental study an analytical method is developed to predict the pressure loss of a MR fluid as a function of the applied magnetic field strength, volumetric flow rate, and surface topology, without utilizing the concept of shear yield stress. A channel flow rheometer with interchangeable channel walls is built to demonstrate that the pressure loss across the MR fluid flow channel is significantly affected by the channel surface properties. Based on the experimental study it is concluded that a unique shear yield stress cannot be defined for a given MR fluid, since its pressure drop depends on the surface topology of the device. Therefore, a relation for nondimensional friction factor associated with MR fluid channel flow is developed in terms of a modified Mason number and dimensionless surface topology parameters. Using the nondimensional model, the pressure loss for various magnetic fields and volumetric flow rates can be represented by a single master curve for a given channel surface topology without the assumption of a constitutive model for MR fluids. © 2011 American Society of Mechanical Engineers. Source
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 0.00 | Year: 2003
An innovative tunable vibration absorber (TVA) concept was developed in the Phase I feasibility study. This design was selected among others to be developed in full scale in Phase II and Phase II Option based on a detailed theoretical modeling, smallprototype test results, and a cost analysis, which were conducted in Phase I.In Phase II and Phase II Option a new generation of TVA utilizing a class of magneto-rheological (MR) materials as the controllable medium will be designed, built and tested in full scale. This system will provide controllable vibration isolation for theUS Navy's FBM launch system. The proposed TVA system consists of a MR material, a compact device, and a robust control system. The proposed system offers advantages, such as, fail-safe, material stability, lack of seal wear, and environmental protectioncorrosive nature of seawater.The effort to achieve the objectives includes: (1) material preparation and characterization of a MR material system suitable for this particular application, (2) theoretical study, design, and construction of the proposed large-scale MR-based TVA device,(3) design and implementation of a robust control system that can provide accurate and fast response, and (4) full-scale testing of the integrated system (Phase II Option). The anticipated result for the Phase II and Phase II Option MR-based TVA will be full-scale device that supports a flexible payload for future FBM launch system applications. This device will provide a controllable reaction force through energizing anelectromagnet that then changes the MR-based material storage and loss properties. MR-based materials can have a significant increase in their storage modulus in the presence of a magnetic field. The Phase II and Phase II option MR-based TVA large-scaleprototype and testing will be the bridge to Phase III production delivery.It is also anticipated to extend the benefits of this technology to other applications and markets through product development for both military and private sectors. In addition to the FBM launch system applications, other Department of Defenseapplications include: HMMWV, weapon recoil systems, flexible gun tubes, helicopter main rotor assembles and suspension mechanisms of ground combat vehicles providing enhanced ground speed over rough terrain. A MR-based TVA may significantly enhance theperformance of systems such as the 30mm and 40mm chain gun, 50 caliber machine guns, large caliber tank artillery, and even individual crew served tactical weapon systems.Private sector commercialization opportunities exist for light and heavy-duty vehicle suspension, vehicle engine mounts and bushings, aircraft landing gear systems, rotating machinery and power plant mounts, sensitive electronic equipment vibrationisolation, as well as automation and motion control for industrial manufacturing systems.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 998.93K | Year: 2011
The focus of the Phase II project will be on design, fabrication, and testing of an adaptive vertical support group AVSG with an active shock and vibration control system (ASVCS) that can mitigate shock and vibrations and increase mission capability for and to support variable payload systems. The Phase II effort will be conducted on the AVSG mount, test fixture development, design and development of test elements, and testing. For Phase II Option I, the AVSG assembly will be designed, developed and tested with ASVCS to evaluate its performance. For Phase II Option II, the integration capability of the system with underwater launch platform interfaces will be studied through the engineering analysis.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 492.71K | Year: 2015
This SBIR Phase II effort will be aimed towards designing and testing a controllable missile lateral support system (LSS) that reacts automatically to shock and vibration inputs. A sub-scale lateral support system (LSS) assembly consisting of six jacking feet and a full-scale LSS jacking feet unit will be fabricated and tested. The electromechanically actuated LSS will offer controllable damping to protect the payload from shock and vibrations events, while having the capability of aligning the canister within the missile tube. The proposed design concept will utilize a smart material to provide automatically controllable shock and vibration damping for variable payload weights contained within the missile tube. In Phase II a control system will be developed for optimized performance of the scaled LSS and for integration with ship controls.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 79.97K | Year: 2014
This Small Business Innovation Research (SBIR) Phase I effort will demonstrate the feasibility of a fail-safe reusable Forward Closure System (FCS) for use in underwater launch tubes. The proposed FCS will be reusable, fail-safe, scalable, capable of withstanding pressures, and have an opening time on the order of milliseconds, while protecting a payload from exposure to sea conditions. Multiple actuation methods and sealing methods will be designed, analyzed, and evaluated. The objectives of this effort are to: 1) Design reusable FCS concepts, 2) Evaluate the FCS designs through analysis, modeling, and simulation, 3) Perform a trade study for down selection, 4) Demonstrate that the requirements are met, and 5) Demonstrate operability to sub-scale laboratory bench testing. By successful completion of the project, a fail-safe reusable FCS design will be delivered along with analysis, simulations, and bench-testing results to show the feasibility for use in underwater launch tubes.