Diseño de un banco de ensayo para hélices de barco.
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Date
2024
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Publisher
Universidad de Concepción
Abstract
La asignatura “Integración a través de CDIO”, impartida a los estudiantes de Ingeniería Civil Aeroespacial y Mecánica, busca aplicar conocimientos ingenieriles adquiridos hasta la fecha, en la construcción de un buque carguero, el cual debe ser concebido, diseñado, implementado y operado, y cumplir una misión, buscando optimizar el tiempo en realizarla, la capacidad de carga y los costos asociados. Actualmente, el sistema de propulsión a utilizar no es elegido por algún criterio específico. Esta necesidad impulsa el diseño de un banco de ensayo para comparar sistemas de propulsión y conocer su empuje y consumo eléctrico de conjuntos hélice – motor. El banco de ensayo que se diseña en este proyecto sigue la metodología CDIO durante su desarrollo.
Al concebir, se determina que el banco medirá el empuje producido por el sistema de propulsión hélice – motor, voltaje y corriente consumidos, y RPM en el eje de transmisión. Además, debe ser sumergible en agua, por lo que se propone un sello estanco para la salida del eje de transmisión.
En la etapa de diseño se planifica el sistema de medición y las conexiones, se realizan los modelos CAD del banco de ensayo para luego ser mecanizados con una maquina fresadora CNC.
En la implementación el banco de ensayo es fabricado, ensamblado, nivelado con la horizontal e instalado en el canal de pruebas para su operación. Se realiza la calibración de los sensores. Se desarrolla un sistema de control de RPM y el código de Arduino. Se realizan modificaciones en el banco y sus sistemas para solucionar limitantes que acontecen durante esta etapa.
Es posible comprobar mediante un análisis de estabilidad para cuerpos flotantes, que el banco de ensayo tiene una flotación estable ya que su metacentro se encuentra sobre su centro de gravedad.
Se realiza el ensayo de dos hélices de paso 80 [mm], de Ø55 y Ø52 [mm], con un motor de corriente continua de 100 [W] de potencia. Existe ruido en las mediciones, pero se observa una tendencia que responde a las variaciones de potencia entregada al motor. Utilizando criterios de comparación, se concluye que, si bien ambas hélices consumen una potencia parecida durante las pruebas, la hélice de mayor diámetro tiene una mayor capacidad de producir empuje que la de Ø52 [mm] en condiciones similares de operación. La precisión de las mediciones depende de una correcta nivelación.
Con el banco de ensayo implementado, operativo y validado, los objetivos de trabajo propuestos son cumplidos y se logra satisfacer la necesidad de seleccionar un sistema propulsor hélice – motor según su desempeño, en la asignatura “integración a través de CDIO”.
The course "Integration through CDIO", offered to Aerospace and Mechanical Engineering students, aims to apply engineering knowledge acquired to date in the construction of a cargo ship. This ship must be conceived, designed, implemented, and operated to fulfill a mission, focusing on optimizing the time required to complete it, the cargo capacity, and associated costs. Currently, the propulsion system to be used is not chosen based on any specific criterion. This need drives the design of a test bench to compare propulsion systems through thrust and electrical consumption measures of propeller-motor combinations. The test bench is developed follows the CDIO methodology. It is conceived that the test bench will measure thrust produced, voltage and current consumed, and RPM of the transmission shaft. Additionally, it must be submersible in water, so a watertight seal is designed for the transmission shaft exit. In the design phase, the measurement system and connections are planned, and CAD models of the test bench are created to later be machined using a CNC milling machine. The watertight seal is designed too. During the implementation phase, the test bench is manufactured, assembled, leveled horizontally, and installed in the test channel for operation. Sensor calibration is performed. A RPM control system and Arduino code is developed. Modifications are made to the bench and its systems to address limitations encountered during this phase. Through a stability analysis of floating bodies, it was verified that the test bench has stable flotation as its metacenter is above its center of gravity. Two propellers with 80 [mm] pitch and Ø55 y Ø52 [mm] are tested using a 100 [W] direct current motor to compare their performance. There is noise in the measurements, but a trend is observed that responds to variations of power delivered to the motor. Using comparison criteria, it is concluded that, although both propellers consume similar power during tests, the larger diameter propeller has greater capacity to produce thrust than the Ø52 [mm] one, under similar operating conditions. The precision of measurements depends on correct leveling. With the test bench implemented, operational and validated, the proposed work objectives are met, and the need to select a propeller – motor propulsion system based on its performance in the "Integration through CDIO" course, is fulfilled.
The course "Integration through CDIO", offered to Aerospace and Mechanical Engineering students, aims to apply engineering knowledge acquired to date in the construction of a cargo ship. This ship must be conceived, designed, implemented, and operated to fulfill a mission, focusing on optimizing the time required to complete it, the cargo capacity, and associated costs. Currently, the propulsion system to be used is not chosen based on any specific criterion. This need drives the design of a test bench to compare propulsion systems through thrust and electrical consumption measures of propeller-motor combinations. The test bench is developed follows the CDIO methodology. It is conceived that the test bench will measure thrust produced, voltage and current consumed, and RPM of the transmission shaft. Additionally, it must be submersible in water, so a watertight seal is designed for the transmission shaft exit. In the design phase, the measurement system and connections are planned, and CAD models of the test bench are created to later be machined using a CNC milling machine. The watertight seal is designed too. During the implementation phase, the test bench is manufactured, assembled, leveled horizontally, and installed in the test channel for operation. Sensor calibration is performed. A RPM control system and Arduino code is developed. Modifications are made to the bench and its systems to address limitations encountered during this phase. Through a stability analysis of floating bodies, it was verified that the test bench has stable flotation as its metacenter is above its center of gravity. Two propellers with 80 [mm] pitch and Ø55 y Ø52 [mm] are tested using a 100 [W] direct current motor to compare their performance. There is noise in the measurements, but a trend is observed that responds to variations of power delivered to the motor. Using comparison criteria, it is concluded that, although both propellers consume similar power during tests, the larger diameter propeller has greater capacity to produce thrust than the Ø52 [mm] one, under similar operating conditions. The precision of measurements depends on correct leveling. With the test bench implemented, operational and validated, the proposed work objectives are met, and the need to select a propeller – motor propulsion system based on its performance in the "Integration through CDIO" course, is fulfilled.
Description
Tesis presentada para optar al título de Ingeniero Civil Aeroespacial
Keywords
Banco de ensayo, Hélices, Barcos Diseño