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A constant volume, zero-dimensional reactor for ideal gas mixtures (CVR) was implemented using Cantera within KIVA-4 in order to simulate a homogeneous charge compression ignition engine (HCCI). Only partial densities are exchanged between KIVA and Cantera. An initial partial density is calculated by KIVA for Cantera. New densities are generated by Cantera using the CVR and are given back to KIVA. Finally, the calculations are completed by KIVA in the main iteration scheme. No further modifications for constitutive equations or models were made for KIVA-4 or Cantera. In order to maintain the constant volume assumption in each cell and solve the CVR, a double adaptive time step is used within the computational fluid dynamics (CFD) code. The time scheme solves a large time step for the CFD and a comparatively small time step for the kinetic reactions. For the fluid phase, time step is increased if there is a low heat release in all cells.

The purpose of this work was to study the use of blends with up to 10% of bio-fuels in Bogotá. Two and three component mixtures were used containing petroleum petrodiesel fuel plus crude and refined African palm oil, oleine and anhydrous ethanol. Tests were made on the exhaust gases for opacity and weight of the particulate matter retained by filtration on glass filters. Torque, power, rpm and temperature of the combustion gases were recorded. Tests were run for NOx, CO, and SOx. Three different diesel engines were used: a single cylinder Lister engine fitted for tests, a 6 cylinder Cummins engine and a 6 cylinder Caterpillar engine. The results show a positive potential of palm oil RBD, palm oil oleine and anhydrous ethanol for blends with commercial petroleum diesel fuel in the Andes mountains.

This paper shows the test results for the evaluation of the performance of an articulated bus prototype fueled with compressed natural gas (CNG). The results will be used to establish the technical viability of the fleet implementation in the mass transport systems of the biggest Colombian cities. In order to carry out the evaluation, some SAE recommended practices were modified to apply to this kind of bus. Performance parameters like tanks filling time, acceleration, startability, driveability, fuel consumption, and flexibility were obtained. The tests were made in two different cities, the first one was Bogota, Colombia's capital with 10 million inhabitants and located at 2,600 meters above sea level (masl). The second city was Cali, with 4 million inhabitants and located at 900 masl.