The flow and turbulence in an IC engine cylinder were studied using the SSG variant of the Reynolds stress turbulence closure model. In-cylinder turbulence is characterized by strong turbulence anisotropy and flow rotation, which aid in air-fuel mixing. It is argued that solving the differential transport equations for each turbulent stress tensor component, as implied by second-moment closures...

The present work aims to assess the influence of composition blends hydrogen (H2) and Natural Gas (NG) on Dual Fuel (DF) combustion characteristics, including gaseous emissions. 3D-CFD study is carried out by means a customized version KIVA-3V code. An automotive 2.8 L, 4-cylinder turbocharged diesel engine was previously modified in order operate DF NG–diesel mode, tested at dynamometer bench....

A droplet vaporization model has been developed for use in high pressure spray modeling. The model is a modification of the common Spalding vaporization model that accounts for the effects of high pressure on phase equilibrium, transport properties, and surface tension. The new model allows for a nonuniform temperature within the liquid by using a simple 2-zone model for the droplet. The effect...

Computational Fluid Dynamic (CFD) simulations using the AVL Fire and Kiva 3v codes were performed to examine commonly accepted techniques and assumptions used when simulating direct injection diesel engines. Simulations of a steady state impulse swirl meter validated the commonly used practice of evaluating the swirl ratio of diesel engines by integrating the valve flow and torque history over ...

We report on a RISC-V extension for a novel multi-core computer organization able to execute applications with high performance and energy efficiency. Novel features of this architecture include support for data objects represented by trees of 128-byte memory chunks, and hardware implementation of task scheduling and load balancing. We call our project Fresh Breeze1 in view of its novelty and p...

Recent years have seen an explosion in the use of Peer-to-Peer (P2P) lending, in which websites such as Kiva and Microplace offer individuals the ability to make loans to microfinance borrowers across the developing world. Such sites offer a fascinating new example of a two-tiered monitoring device in which micro-finance institutions (MFIs) maintain dynamic relationships with borrowers and P2P ...

Whether cases of bullying should be handled in a direct, condemning mode or in a manner that does not involve blaming the perpetrator is a controversial issue among school professionals. This study compares the effectiveness of a Confronting Approach where the bully is openly told that his behavior must cease immediately to a Non-Confronting Approach where the adult shares his concern about the...

Consider a routing problem for a team of vehicles in the plane: target points appear randomly over time in a bounded environment and must be visited by one of the vehicles. It is desired to minimize the expected system time for the targets, i.e., the expected time elapsed between the appearance of a target point, and the instant it is visited. In this paper, such a routing problem is considered...

Landfill gas (LFG) that is generated in an anaerobic environment in landfills and consists primarily of methane and carbondioxide with small amount of nitrogen and other non-methane gases, could be collected and used to produce energy either by extracting methane or using the landfill gas directly in an internal combustion engine or a gas turbine. It amounts to be a net-negative greenhouse gas ...

Risk factors for same- and other-sex victimization were examined in a longitudinal data set involving 9- to 14-year-old students. The findings regarding same-sex victimization supported the view that bullies select personally and interpersonally vulnerable targets in order to maximize their gains in status while minimizing loss of affection within their same-sex peer group. Although low self-es...