Modernizing small model tank for comprehensive testing outboard motors

Abstract

The article focuses on modernization of a small model tank in Astrakhan State Technical University, which was used for comprehensive testing of outboard motors and analyzing the exhaust gases of outboard motors for harmful emissions. Modernization was undertaken to expand the types of experiments carried out with outboard motors based on a previously obtained utility model patent RU 196596 U1, 06.03.2020. The small experimental pool was equipped with technical means, such as a device (pipe outlet) for redirecting the water flow from the outboard motor propeller and measuring instruments for determining the level of noise, vibration, temperature, etc. For further testing, it was necessary to evaluate the amount of heat discharged into the water by exhaust gases from the deadwood of the outboard motor, by friction developed by the propeller in the water, by heating during operation of the bevel hypoid gear in the gearbox of the outboard motor, by using various types of lubricating oils. All these caused the need to equip the small experimental pool with thermal insulation to save heat. Due to the special requirements for the thermal insulation of the small experimental pool, namely, a small thickness of the coating, neutrality when interacting with combustible materials and lubricants there was used a heat-insulating paint produced by NPP Termalcom, LLC, Astratek Metal brand. To measure the specific parameters, in particular, noise of the gas exhaust system of an outboard motor, there arose a problem to conduct the experiments in the tank with an open lid, which could result in splashing water during the propeller rotation. A detailed description of technical solutions, designs and principles of action to eliminate the identified shortcomings in a small experimental pool is given.