Maximizing the Performance of Cased Munitions Under Realistic Constraints

Author(s):  
Kenneth C. Walls ◽  
David L. Littlefield ◽  
David E. Lambert

In order to make the process of fragmentation of warhead cases more systematic, we have developed a procedure that makes use of nonlinear optimization to derive optimal values for case design parameters subject to various design constraints. A framework has been developed that makes use of the optimization software package LS-OPT driving the hydrocode CTH (CTH is developed and maintained at Sandia National Laboratories, LS-OPT is commercially available from Livermore Software Technology Corp.). CTH was used to model the explosive detonation and determine the resultant kinetic energy delivered to the case by the energetic material. As an example of application of the framework, a test problem was run using a case configuration consisting alternating titanium alloy and polymer layers.

Author(s):  
Kenneth C. Walls ◽  
David L. Littlefield ◽  
David E. Lambert

In order to make the process of fragmentation of warhead cases more systematic, we have developed a procedure that makes use of nonlinear optimization to derive optimal values for case design parameters subject to various design constraints. A framework has been developed that makes use of the optimization software package LS-OPT driving the hydrocode CTH (CTH is developed and maintained at Sandia National Laboratories, LS-OPT is commercially available from Livermore Software Technology Corp.). CTH was used to model the explosive detonation and determine the resultant kinetic energy delivered to the case by the energetic material. In this follow-on effort to a previous study [1], the range of constraints and free parameters used in the optimization study was expanded.


2019 ◽  
Vol 1 (3) ◽  
pp. 1-10
Author(s):  
Mikhail M. Konstantinov ◽  
Ivan N. Glushkov ◽  
Sergey S. Pashinin ◽  
Igor I. Ognev ◽  
Tatyana V. Bedych

In this paper we consider the structural and technological process of the combine used in the process of separate harvesting of grain crops, as well as a number of its parameters. Among the main units of the combine, we allocate a conveyor and devices for removing beveled stems from under the wheels of the vehicle. The principle of operation of the conveyor at different phases of the Reaper and especially the removal of cut stems from under the wheels of the vehicle during operation of the Reaper. The results of theoretical studies on the establishment of the optimal design of the parameters of the belt conveyor are presented, the ranges of their optimal values are considered and determined. Studies on the establishment of optimal parameters of the screw divider in the Reaper, which is the main component of the device for removal of beveled stems, are presented. Taking into account the optimal design and mode of operation of the screw divider, the correct work is provided to remove the cut stems from under the wheels of the harvester.


2012 ◽  
Vol 452-453 ◽  
pp. 1351-1355 ◽  
Author(s):  
Grzegorz Wszołek ◽  
Piotr Czop ◽  
Dawid Jakubowski ◽  
Damian Slawik

The aim of this paper is to demonstrate a possibility to optimize a shock absorber design to minimize level of vibrations with the use of model-based approach. The paper introduces a proposal of an optimization method that allows to choose the optimal values of the design parameters using a shock absorber model to minimize the level of vibrations. A model-based approach is considered to obtain the optimal pressure-flow characteristic by simulations conducted with the use of coupled models, including the damper and the servo-hydraulic tester model. The presence of the tester model is required due to high non-linear coupling of the tested object (damper) and the tester itself to be used for noise evaluation. This kind of evaluation is used in the automotive industry to investigate dampers, as an alternative to vehicle-level tests. The paper provides numerical experimental case studies to show application scope of the proposed method


2020 ◽  
Vol 9 (1) ◽  
pp. 7-16

The conventional wastewater (WW) treatment plant includes physical, chemical, and biological treatment processes that can protect the receiving water bodies from water pollution. The common design constraints, challenges as well as environmental impact would make the wastewater treatment plant’s (WWTP) construction and operation more complex and demanding tasks. Major project constraints for WW plant design are economic, accessibility, fulfilling technical requirements, institutional set-up, health and environment, personnel capacity, and political commitment etc. Design methodology adopted in the current study included project location, unit selections, the design capacity, design period as well as proximity to the population and layout plan. The present manuscript discussed briefly about effluent quality requirements, design issues, environmental impacts, details, and safety concerns. It also highlighted the necessary flexibility to carry out satisfactorily within the desired range of influent WW characteristics and flows. In the present study, every step of the design was verified with Environmental Regulations and suggested to overcome all constraints while designing WWTPs so that standard operational code for the specific region could be implemented to achieve the best treatment performance. The results obtained from analytical calculation were optimized to achieve the best design parameters for field application. The optimized values also reduce the construction and operation cost during the field application.


1999 ◽  
Vol 121 (1) ◽  
pp. 114-120 ◽  
Author(s):  
Jiasheng Zhu ◽  
Kyosuke Ono

In this paper, the static and dynamic performance of herringbone, step-pocket, taper-pocket, and taper-flat thrust bearings were numerically analyzed. Optimal values for the design parameters of each type of bearing were analyzed in terms of both maximum axial stiffness (kzz) and maximum ratio of axial stiffness to friction torque (kzz/T) and bearing performance for both cases was calculated. The optimal performance characteristics of these bearings were compared in terms of application to hard disk spindles. Step-pocket and taper-pocket thrust bearings are superior to herringbone and taper-flat thrust bearings with respect to both the maximum kkk and the maximum kzz/T conditions. It was found that the dams of thrust bearings with pockets play an important part in improving the hearing performance. It was made clear that the taper-pocket and the taper-flat thrust bearings have a much larger load capacity than the other two types of thrust bearings in the proximity of zero clearance.


In this paper a Single stage and Two stage Half Bridge LLC (HB LLC) converter topologies for DC/DC applications with low input voltage. The basic operation and design procedure for LLC converter is illustrated. Simulation of the proposed converter is done using the design parameters and the results are discussed and then analysis is done to know its performance. The efficiency of the converters is analyzed by MATLAB Software Package.


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