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DENSO started a pilot demonstration of on-site methanation as “CO2 circulation plant” as proactive initiative for CO2 capture and storage/utilization (CCUS) technologies toward achievement of carbon neutrality by 2035 in our own business. The CO2 circulation plant was designed to capture CO2 primarily generated by the plant and recycle it as an energy source of the facility. We also started work on the development of electric swing CO2 adsorption (ESA) technology to achieve low-energy CO2 capture.

A response surface model of a diesel spray, parameterized by the internal geometries of a nozzle, is established in order to design the nozzle geometries optimally for spray mixing. The explanatory variables are the number of holes, the hole diameter, the inclined angle, the hole length, the hole inlet radius, K-factor and the sac diameter. The model is defined as a full second-order polynomial model including all the first-order interactions of the variables, and a total of 40 sets of numerical simulations based on D-optimal design are carried out to calculate the partial regression coefficients. Partial regression coefficients that deteriorate the estimate accuracy are eliminated by a validation process, so that the estimate accuracy is improved to be ±3% and ±15% for the spray penetration and the spread, respectively. Then, the model is applied to an optimization of the internal geometries for the spray penetration and the spray spread through a multi-objective genetic algorism.

Hypersonic Transport Propulsion System Research (HYPR) Project was started in 1989 to develop the technologies for the propulsion system of a Mach 5 HST airplane, which could be environmentally acceptable and economically viable. The engine being studied is the combined cycle engine composed of a turbo engine which can operate from take-off to Mach 3 and a ramjet engine which can operate over Mach 2.5 to Mach 5. The variable cycle engine (VCE) concept is applied to the turbo engine to satisfy the requirements for low noise level at take-off and high specific thrust at high altitude and speed. The design and manufacture of demonstrator engines have been performed. The first turbo engine test and the first heated inlet test of the core engine was carried out successfully in December 1994 and March 1995 respectively. This paper describes the turbo engine design and those test results.

Making use of advantages of ducted fan, i.e. compactness and approachability, ducted fan VTOL can be used for many purposes, such as construction and servicing of the tall structures, rescue, etc.. In this paper the development of a working platform which utilizes the ducted fan VTOL concept is tried. Two types of ducted fan VTOL research models are developed. One is driven by electric motors and the other by an engine. The aim of the development is to investigate the ability of the ducted fan VTOL as a platform for working tasks at a high position. One of the most important problems for the development of the working platform in air is the development of control system which enable precision hovering. In this paper mainly the automatic flight control system for ducted fan VTOL is investigated and the control problems are studied which will arise when the VTOL is utilized as a working platform.

It is often realized that the control system design utilizing modern state space theory produces unstable controllers. Such unstable controllers which should stabilize the plant theoretically, do not really stabilize the plants when they are implemented. Unstable controllers are not preferable from the view point of robustness and safety. Even if an unstable controller can stabilize the plant, it works well only when it is operating with the original plant. When some accident occurs and the feedback loop is cut, unstable motion of controller brings the worst results. In the design of control system for many aerospace vehicles and space structures, classical design methods of compensator are not applicable and only the modern techniques can be utilized, where the number of states, inputs and outputs are very large. In such cases, controllers should include high dimensional complex dynamics.