Yoshinori Idota

There are applications where a micro gas turbine (MGT) needs to be started frequently especially when used as a distributed power source. Therefore, stable light-up is a very important characteristic for the low-emission combustor of an MGT. Light-up is affected by several factors, including the equivalence ratios, the temperature of the fuel-air mixture, and the ignition energy. The purpose of this paper is to clarify the relationship between the ignitability and the equivalence ratios of the fuel-air mixture at the tip of the spark plug. We have developed an instrument that uses the principle of infrared absorption by a CH-bond to measure the time-resolved equivalence ratios for the lean premixed combustor. As a result, the mixture could be ignited within an equivalence ratio range of approximately 0.5 to 1.4. These results were found to agree with measurements taken for a homogeneous mixture in a constant volume chamber. In addition, in the case of the fuel supply for combination, the distribution of the equivalence ratio across the diameter had a large slope in the vicinity of the liner wall of the combustor, ralative to the case of the fuel supply for diffusion.

As various new communication services are introduced in automobiles, integration of receivers for the various services is desired. Thus, we propose a new method by which to receive multiple services simultaneously using one piece of hardware. This method is referred to herein as Simultaneous Reception with Time-sharing Filter. In the proposed method, received signals of multiple communication services are down-converted to appropriate intermediate frequency signals, multiplexed on a cable, and then received simultaneously in an integrated receiver. The proposed method can reduce the number of cables and receivers. In this paper, we first explain the proposed method of Simultaneous Reception with Time-sharing Filter. We then introduce the prototype system developed to confirm the validity of the proposed method. Finally, we show the experimental results of simultaneous reception of DSRC, FM broadcasting and DTV using the prototype system.

Tadao Ogawa, Masanori Okada

In a previous paper, a number of diesel fuels, exhaust gasses and the soluble organic fractions (SOFs) in the particulate matter (PM) were analyzed. The results revealed that SOF was primarily associated with the high boiling point components in the fuel and the soot in PM was primarily associated with the ratio of hydrogen to carbon (H/C) of the fuel. In addition, a regression equation which consists of the backend fraction at 310^｡C (R₃₁₀) and H/C of fuel: PM = a × R₃₁₀ + b (H/C) + c, proved useful for estimating PM emissions.

In this paper, the regression equation was applied to existing-step research and model-step research conducted by the Diesel Working Group (WG) of the Japan Clean Air Program (JCAP). Consequently, PM emissions from the existing-step research were well estimated using the R₃₁₀ and the H/C and most of the PM emissions from the model-step research were also well estimated using the R₂₉₀ and the H/C.　

Tadao Ogawa, Masanori Okada

To clarify the influence of the composition of aliphatic hydrocarbons and aromatic hydrocarbons on emissions, two series of fuels were prepared by the Combustion Analysis Working Group of the Japan Clean Air Program. The two series of fuels, which were named "Aliphatic fuels" and "Aromatic fuels", respectively from their compositions in this paper, were analyzed using precise analytical methods. In addition, the relationship between the fuel properties and particulate emissions from a single-cylinder engine was also regressively analyzed. As a result, the particulate emissions from "Aromatic fuels" were estimated by the backend fraction and the H/C of the fuels, whereas the particulate emissions from "Aliphatic fuels" could not be estimated by the two parameters. The particulate emissions from "Aliphatic fuels" were found to be influenced by the composition of structural isomers, which cannot be evaluated using the H/C. For the "Aliphatic fuels", the relationship between the fuel properties and particulate emissions were explained by precise analytical results for the fuels.