Distance Staff Cooperation in On-Line Engineering M.T. Restivo 1, J.G. Mendes 1, G. Schmerl 2, I.S. Carvalho 1,3, E. Barreira 4, A. Penninger 2, G. Gróf 2, A. Bereczky 2, V.P. de Freitas 4 1 UISPA, IDMEC-FEUP, Faculdade de Engenharia da Universidade do Porto, Portugal 2 Department of Energy Engineering, BME-BUTE, Budapest, Hungary 3 Instituto Superior de Engenharia de Lisboa, Portugal 4 Faculdade de Engenharia da Universidade do Porto, Portugal trestivo@fe.up.pt Abstract The on-line meteorological station at the Faculty of Engineering of University of Porto (FEUP) has been an example of a very successful remote lab of sensitive type for several years. In the very recent past it also has been a example of joint work under an international cooperation program between the Portuguese System Integration and Process Automation research Unit at IDMEC-FEUP, the Building Physics Laboratory at FEUP, and the Hungarian Budapest University of Technology and Economics. In fact, the familiarity with meteorological data is important either for research or for teaching aims in different engineering areas. This meteorological station at FEUP has been a popular remote lab for other Universities in Portugal and also for many high schools. 1. Introduction The Building Physics Laboratory was possibly the first lab at FEUP to deliver online data related with meteorological physical quantities from the station available in the former FEUP location at Porto town center, in the 1990s. In 2000 the Faculty moved to the present Campus and so did the station. Later, a mechanical engineering undergraduate student, supervised by the first and second authors, built a webpage for making available the station data as well as their recording in a database every 10 min. The temperature, wind velocity and direction, pressure, relative humidity, sun radiation (in north, east, south, west and horizontal directions) and rainfall data have been collected for R&D and for student work for several years, up to 2008. The page also got some other links and information, namely related with the instrumentation itself or with old type instruments and some links to the Portuguese Meteorological Institute. A night vision outdoor IP camera mounted in protecting housing with heater and fan elements for coping with extreme weather conditions, provided station live video to the webpage. This webpage has been very popular in the past and some links from other educational institutions were permanently done to it. However, the malfunction of the old meteorological station forced its replacement by a new one. The new station had to be tuned and the software interface reformulated in order to get on-line information of the urban climate at FEUP. These tasks have been performed during a three-week visit to FEUP of one collaborator from the BME-BUTE and since then further tasks were developed by VPN connection from Budapest University to the local web server at FEUP where the work is still involving two Departments, Civil and Mechanical Engineering. In fact, at present a two year joint project is running between the Department of Energy Engineering (BME), Faculty of Mechanical Engineering of the Budapest University of Technology and Economics in Hungary and the research unit UISPA at the Mechanical Engineering Institute at FEUP, in Portugal. The project is mainly devoted to the Sharing of Tools and Methodologies in Engineering Education. Within this project students from both partner countries are performing on-line experiments using remote access to labs on either University. Promoting international cooperation in Engineering Education is of high relevance in these days of global engineering, [1], [2] and [3]. It not only increases student awareness and motivation but also exposes them to other education systems, curricula and learning tools. In addition to the transfer of pedagogical knowledge we have also been looking for sharing technical and scientific know-how by collaborating in providing experimental improvements. Finally, the use of these resources on each country by the collaborators and their students also justifies and proves one of the main remote labs underlying ideas. Recently a mission from the Hungarian partner at FEUP was responsible for tuning and developing the software interface for the new meteorological station, figure 1. This is one experiment available at http://elabs.fe.up.pt/, among others, [4] and [5].
2. Some technical features Fig. 1. Remote access to the station This sensitive remote lab aims to contribute to the urban climate characterization of Porto. Several physical quantities (temperature, wind velocity and direction, pressure, relative humidity, direct and diffuse solar radiation, atmospheric radiation, terrestrial radiation and rainfall), figure 2, are available every 10 minutes within the Campus of FEUP. All the data is recorded in a database for later use by anyone accessing the system. An IP camera feeds the site with real time video. The meteorological station is equipped with a data logger (Micromec Logbox). However it was not possible to use its software for saving and sending data automatically. The main task of the Hungarian partner element was the development of a software application to collect data from the station datalogger, to record them in a database and to share the data with the Internet webpage. It also restarts automatically the measuring cycle and synchronizes the logger date and time with the one on its own computer. Then the application was developed using LabVIEW 8.5. It reads continuously data from the logger independently from the logger's memory. It saves data to a file and emails it. There is a database on the. The Labview software application sends values to the database and the webpage can read them too and can make available the last set of written values, which could mean every 10 min (other periodicity can be settled). 3. Pedagogical scopes When pedagogical subjects are evaluated with real data and when they are collected by students the results become more meaningful for them. This sensitive lab offers recordable meteorological measured quantities stored in its database, every 10 minutes. 3.1. Usefulness in the civil engineering field Fig. 2. Meteorological station @FEUP: night view This is an example of a sensitive type lab. The data is used in some Civil Engineering courses. In fact, when designing a building it is fundamental to know the surrounding climatic characteristics. Then, care should be taken in the specific design and dimensioning of non structural elements. Those are essential for guaranteeing the success of the building either for the comfort and profitability of its users or for reducing cost of short/long term maintenance. Moreover, the data is also used with mechanical engineering students for exploring the measurement instrumentation [6] used for measuring those different physical quantities relevant either in Wind Energy systems or for Heating, Ventilating, and Air Conditioning systems (HAVC) studies. The data information is available in three languages: Portuguese, English and Hungarian. The specific design and dimensioning of non structural elements in the overall design of a building determine the use of many outside features. For example: The local sun radiation determines the types of glasses and window frames as well as shadows; The local rainfall intensity determines the solution to be used in water drainage; The local predominant wind characteristics have to be considered for a correct selection of the equipments and systems for a inner natural ventilation; The possible phenomenon of freeze/thaw cycles is an important aspect to take into account when choosing the external coating of the building envelope; The outside typical temperatures are fundamental when dimensioning the thickness of the thermal isolation: at Bragança, in northeast Portugal, the outside wall thermal isolation thickness should be over 15% when comparing with the one at Porto and more than 50% if considering a building at Faro, in the south of the country. Portugal is no more than around 700 km long! Also, the same building material could be under more or less intensive degradation related with the local climate.
Combining different values of temperature and relative humidity, this may originate internal condensation in the building material and so increase its degradation. Figures 3 and 4 show wall water content for the locations Porto and Faro. [kg/m3] 70 60 50 40 30 20 10 0 Water content - Porto 0 0,05 0,1 0,15 0,2 0,25 0,3 [m] Fig. 3. Wall water content Porto [kg/m3] 70 60 50 40 30 20 10 Water content - Faro 0 0 0,05 0,1 0,15 0,2 0,25 0,3 [m] Fig. 4 Wall water content - Faro These two figures illustrate the change in the water content considering the local characteristics of temperature and humidity for the wall type sketched in figure 5. It is possible to find higher water content between the thermal isolation and the brick masonry in Porto than in Faro. And this depends on the local climate, [7], [8] and [9]. Civil engineering students that have chosen the Building Physics area are asked, during the last year of their MSc, to simulate the behaviour of a building, regarding its thermal and hygrothermal characteristics. The idea is to use climate data from various Portuguese towns and to understand that the same building elements (wall, roof and floor) may behave differently considering its location. Exterior rendering Brick wall Mineral insulation board Gypsum board Fig. 5. Exterior wall with interior insulation The Civil Engineering Integrated Master includes subjects like Thermics of Buildings and Building Pathology and Rehabilitation where students have to use simplified and, since 2008/09, advanced numerical models to simulate the building behaviour. All this models require climate data. Since this new station began delivering data by March 2009 the students have been using real instead of synthetic data. The reaction of the students is much more positive because they are using familiar data within their own work environment which they can get from the records of the station database. This gives a brief idea of how the data can be useful for students to work out many building aspects and solutions. 3.2. Usefulness in the mechanical engineering field In some areas of the mechanical engineering degree, students are supposed to become familiar with calculations for the correct design of air conditioning systems, using psychrometric diagrams and dedicated commercial software, figure 6, as well as for determining the system efficiency. For those calculations they generally need to know temperature, pressure, relative humidity, and they also need to consider the geographic location and the climate characteristics. In this context working with real data will give more flexible and reliable calculations, rather than working only with typical maxima and minima values. In fact the data recorded in the database makes it possible to consider the weather in the respective area along the year. Another relevant application is related with the influence of ambient air conditions on heat engine performance as well as pollutant emission. The parameters considered most relevant are the air inlet temperature, air humidity and pressure, as is the case of a gas engine [10], [11] and [12].
concerning student benefits will be evaluated later along the final period of this project. 5. References [1] Carvalho I.S., Penninger A., Grof G., Bereczky A., Schmerl G., Restivo M.T., Utilization of Interactive Internet in High Education, in Proceedings of the 9th WSEAS International Conference on Distance Learning and Web Engineering (DIWEB '09), Budapest, Hungary, September 3-5, [2] Machado L. S., Pereira T. A. B., Costa T. K. L., Restivo M. T. and Moraes R. M., Improving Interaction in Remote Laboratories Using Haptic Devices, in Proceedings, International Conference on Remote Engineering and Virtual Instrumentation, REV2007, June 2007, Porto, Portugal, 2007. Fig.6. Commercial software for psychrometric calculations Moreover, students at the fourth year of the Mechanical Engineering Integrated Master have a course on Instrumentation for Measurement where they deal with the different physical quantities measurement, their methodologies and procedures, the working principles of transducers and their application areas. So this is one of the remote experiments available to complement the real hands-on activity within the semester course, [13]. 4. Final remarks Academic staff is constantly demanded to be involved with R&D activities and care has to be taken in using their outcomes, as much as possible, for improving their teaching and learning practices. This case is a convenient example of the link between those two activities. Moreover among many proposed learning activities, international cooperation programs are generally well accepted by students. The students are able to get acquainted with new learning environments and they have the opportunity of perceiving what is being done in other universities and countries in a similar or distinct engineering area. Therefore, this experience in sharing remote labs between two distant universities has contributed for developing new materials, enlarging their usefulness, improving their quality and also pushing together the international cooperation on both institutions. However, due to the recent correlation between the use of the advanced numerical models to simulate the building behaviour and the data from this new station, results [3] Machado, L. S., et al., A Remote Access Haptic Experiment For Mechanical Material Characterization, in Proceedings of the 8th Portuguese Conference on Automatic Control, CONTROLO'08, pp. 870-874, Vila Real, Portugal, 2008. [4] Restivo M.T., Mendes J., Lopes A.M., Silva C.M., Chouzal F., "A Remote Lab in Engineering Measurement," IEEE Trans. on Industrial Electronics, Vol. 56, [5] Restivo M. T. and Silva M. G., Portuguese Universities sharing remote laboratories, published in Special Issue: IRF'09 of ijoe - International Journal of Online Engineering, Vol 5 (2009), pp. 16-19, November [6] Restivo M. T., Almeida F. G., Chouzal M. de F., Mendes J. G., Lopes A. M., Mesurement: Concepts, Methods and Practice within an Electronik Book, published in Slovakian Acta Electrotechnica et Informatica, Vol. 9, No. 1, pp. 51 56, [7] N. Ramos; J. Delgado; E. Barreira; V. P. Freitas, Propriedades higrotérmicas utilizadas em simulação numérica. PATORREB 2009, published in Actas PATORREB 2009-3º Encontro sobre Patologia e Reabilitação de Edifícios, pp. 429-434, Porto, March [8] N. Ramos; E. Barreira; J. Delgado; V. P. Freitas, Análise de condensações internas em paredes - Aplicação de Modelos de Diferente Complexidade, published in Actas PATORREB 2009-3.º Encontro sobre Patologia e Reabilitação de Edifícios, pp. 435-440, Porto, March
[9] N. Ramos; J. Delgado; E. Barreira; V. P. Freitas, Hygrothermal properties applied in numerical simulation: Interstitial condensation analysis, Journal of Building Appraisal, Vol. 5, Issue 2, pp. 161-170, October [10] CIMAC GAS ENGINES Working Group, About the Influence of Ambient Conditions on Performance of Gas Engines, published by International Council on Combustion Engines, March [11] S.P. Kavanaugh, HVAC Simplified, ASHRAE, Atlanta, 2005. [12] ASHRAE Handbook of Fundamentals, ASHRAE, Atlanta, 2005. [13] Restivo M.T., Almeida F.G., Chouzal M. F., Mendes J., Lopes A.M., "Laboratórios de Instrumentação para Medição/Laboratories of Instrumentation for Measurement", bilingual version, Editora UPorto, Portugal, March 2008.