Browse Topic: Military vehicles and equipment

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ABSTRACT This paper presents a quantitative analysis and comparison of fuel economy and performance of a series hybrid electric HMMWV (High Mobility Multi-purpose Wheeled Vehicle) military vehicle with a conventional HMMWV of equivalent size. Hybrid vehicle powertrains show improved fuel economy gains due to optimized engine operation and regenerative braking. In this paper, a methodology is presented by which the fuel economy gains due to optimized engine are isolated from the fuel economy gains due to regenerative braking. Validated vehicle models as well as data collected on test tracks are used in the quantitative analysis. The regenerative braking of the hybrid HMMWV is analyzed in terms of efficiency from the kinetic energy at the wheels to the portion of regenerative power which is retrievable by the battery. The engine operation of both the series hybrid and conventional HMMWV are analyzed using a 2-D bin analysis methodology. Finally, the vehicle model is used to make
Nedungadi, AshokMasrur, AbulKhalil, Gus
ABSTRACT The performance of ground vehicles during a rollover event is an important safety and occupant protection requirement for military vehicles. Modeling and simulation is a very useful tool in study and investigation of vehicle rollover characteristics and countermeasure concepts. This study presents two methods of simulating the rollover events. The first one uses Full System Method (FSM), where all the components are modelled as is and are evaluated. The second method is a reduced order modelling method (ROMM) using integration of the resulted kinematics data from FSM into the vehicle model with occupant & restraints. The FSM & ROMM methods were applied to simulate two HMMMV rollover events, and the results from both methods show that simulation and test data agreed fairly well. Computational time reduced by the ROMM was about 53% of that of the FSM. ROMM approach not only saves significant computational time but also increases robustness of the simulation. Citation: V. Babu, J
Babu, V.Kang, J.Kankanalapalli, S.Sheng, J.Vunnam, M.Karwaczynski, S. K.Jessup, C.Duncan, M.Paulson, K.
ABSTRACT Determining the required power for the tractive elements of off-road vehicles has always been a critical aspect of the design process for military vehicles. In recent years, military vehicles have been equipped with hybrid, diesel-electric drives to improve stealth capabilities. The electric motors that power the wheel or tracks require an accurate estimation of the power and duty cycle for a vehicle during certain operating conditions. To meet this demand, a GPS-based mobility power model was developed to predict the duty cycle and energy requirements of off-road vehicles. The dynamic vehicle parameters needed to estimate the forces developed during locomotion are determined from the GPS data, and these forces include the following: the gravitational, acceleration, motion resistance, aerodynamic drag, and drawbar forces. Initial application of the mobility power concept began when three U.S. military’s Stryker vehicles were equipped with GPS receivers while conducting a
Ayers, PaulBozdech, George
ABSTRACT CAMX Power is developing Li-ion pouch cells and batteries based on its proprietary CAM-7® cathode material and commercially available lithium titanate (LTO) anode material to provide high power, high charging rate capability, long life, safety and configurational flexibility in military vehicle batteries. The CAM-7®/LTO technology can be discharged to 0 V with no loss in performance, has excellent tolerance for cell voltage reversal and cell overcharge as well as having excellent elevated-temperature storage stability, making it ideally suited for batteries that can be logistically managed with little or no maintenance or environmental controls. These same properties make CAM-7®/LTO technology well-suited for implementing in damage-tolerant, minimally managed, batteries that are structurally distributed and integrated in military vehicles.
Ofer, DavidKaplan, DanielMenard, MarkYang, CelineDalton-Castor, SharonMcCoy, ChrisBarnett, BrianSriramulu, Suresh
ABSTRACT The US Army is seeking improvements in the fuel efficiency of their military vehicles.. They have initiated a number of R&D projects aimed at advancing the state-of-the-art of powertrain efficiency including demonstration in a laboratory environment. This effort will set a benchmark for the vehicle integrators, allowing them to improve future vehicle offerings. The SAIC, AVL, Badenoch, QinetiQ and Ker-Train Research team offered powertrain solutions from 7 Tons to 40 Tons that achieved the goal of 44% thermal efficiency and the stringent flexible fuel and emissions requirements. In each of these offerings the team was able to identify modifications to existing engines that allowed dramatic improvements in the thermal efficiency. These efficiency improvements were achieved through a combination of techniques, combustion cycle adjustments using in-cylinder pressure monitoring and precise control of fuel injector timing, and turbo-compounding. For the R&D project, the fuel
McDowell, JimHunter, Gary L.Hennessy, Chris
ABSTRACT Imagine Soldiers reacting to an unpredictable, dynamic, stressful situation on the battlefield. How those Soldiers think about the information presented to them by the system or other Soldiers during this situation – and how well they translate that into thinking into effective behaviors – is critical to how well they perform. Importantly, those thought processes (i.e., cognition) interact with both external (e.g., the size of the enemy force, weather) and internal (e.g., ability to communicate, personality, fatigue level) factors. The complicated nature of these interactions can have dramatic and unexpected consequences, as is seen in the analysis of military and industrial disasters, such as the shooting down of Iran Air flight 655, or the partial core meltdown on Three Mile Island. In both cases, decision makers needed to interact with equipment and personnel in a stressful, dynamic, and uncertain environment. Similarly, the complex and dynamic nature of the contemporary
McDowell, KalebZywiol, Harry J.
This SAE Recommended Practice provides minimum performance target and uniform laboratory procedures for fatigue testing of wheels and demountable rims intended for normal highway use on trucks, buses, truck-trailers, and multipurpose vehicles. Users may establish design criteria exceeding the minimum performance target for added confidence in a design. The cycle target noted in Tables 1 and 2 are based on Weibull statistics using two parameter, median ranks, 50% confidence level and 90% reliability, and beta equal to two, typically noted as B10C50. For other wheels intended for normal highway use and temporary use on passenger cars, light trucks, and multipurpose vehicles, refer to SAE J328. For wheels used on trailers drawn by passenger cars, light trucks, or multipurpose vehicles, refer to SAE J1204. For bolt together military wheels, refer to SAE J1992. This document does not cover other special application wheels and rims.
Truck and Bus Wheel Committee
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