An investigation on the acoustical characteristics of an electromagnetic hemianechoic room is her... more An investigation on the acoustical characteristics of an electromagnetic hemianechoic room is here proposed. The research has been carried out within an agreement between the Perugia University Acoustic Laboratory and Angelantoni Industrie S.p.a. Angelantoni Industrie hemianechoic room has been investigated. The room has been created for electromagnetic compatibility tests. It is fully insulated from the outside environment and it guarantees more than 10 KOhms of insulating power. A hybrid solution has been chosen for the anechoic lining of walls and ceiling; the 'quiet zone' is covered by 24" cones coupled to ferrite tiles whereas the remaining parts are covered with 36" cones. No fixed anechoic insulation is on the floor (hemianechoic type). An acoustic measurement campaign has been carried out in order to verify if the investigated room is characterized also by high acoustic hemianechoic performances. Measurements have been led according to ISO 3745. Measurement results have shown that the investigated room, differently from the acoustic typical hemianechoic rooms, accords to ISO 3745 only for 315-20000 Hz frequency range and for a 2.5 m radius hemispheric surface.
Journal of The Acoustical Society of America, 2002
An original prototype for train locomotor exhaust gas pipe noise reduction (electronic muffler) i... more An original prototype for train locomotor exhaust gas pipe noise reduction (electronic muffler) is proposed: the system is based on an active noise control technique. An acoustical measurement campaign has shown that locomotor exhaust noise is characterized by very low frequency components (less than 80 Hz) and very high acoustic power (up to 110 dB). A peculiar electronic muffler characterized by high acoustical efficiency at very low frequencies has been designed and realized at Perugia University Acoustic Laboratory; it has been installed on an Italian D.245 train locomotor, equipped with a 500-kW diesel engine. The electronic muffler has been added to the traditional passive muffler. Very low transmission losses are introduced by the electronic muffler because of its particular shape; thus, engine efficiency does not further decrease. Canceling noise is generated by means of DSP-based numerical algorithm. Disturbing noise and canceling noise destructively interfere at the exhaust duct outlet section; outgoing noise is thus reduced. The control system reduces exhaust noise both in the steady and unsteady engine regime. Measurement results have shown that electronic muffler introduces up to 15 dB noise abatement in the low-frequency components.
An original method to evaluate vibration levels due to road vehicles is proposed. A measurement c... more An original method to evaluate vibration levels due to road vehicles is proposed. A measurement campaign has been carried out to individuate vibration acceleration levels for different typologies of vehicles. Each vehicle passage has been considered as a single event. Vibration levels due to each single event have been measured by means of a data acquisition system. Measurement results allowed to individuate the relations among vibration levels, typology of vehicle, vehicle velocity and soil characteristics. Thus, acceleration levels may be estimated at different distances from the vibration source by adopting a propagation model which has been previously proposed for train induced soil vibrations .
Reduction methods for ultra freezers noise emissions are here studied. The investigated freezer i... more Reduction methods for ultra freezers noise emissions are here studied. The investigated freezer is the model "PLATINUM 750 V", manufactured by Angelantoni Industrie S.p.a.. An intensity and a vibration measurements campaign has been led in order to individuate freezer noise characteristics. A sound pressure measurement campaign have been also carried out for low frequency noise components determination; a comparison has been made between power levels obtained by two measurement methods: intensity and pressure level measurements. Measurements results have shown that freezer fan and compressors are the main noise sources. Thus, some vibration and acoustic insulation solutions have been proposed and realized. Noise reduction solutions performances have been verified by a measurement campaign.
L'incremento della temperatura media della Terra sia esso dovuto a cause naturali che antropiche ... more L'incremento della temperatura media della Terra sia esso dovuto a cause naturali che antropiche è un fatto ormai condiviso da tutta la comunità scientifica. Le conseguenze dell'incremento della temperatura sono evidenti: innalzamento del livello degli oceani, scioglimento dei ghiacci, desertificazione, eventi meteorologici estremi, etc.. Le conseguenze sociali, economiche e politiche sono altrettanto preoccupanti. Studi recenti hanno stimato che l'entità dei danni prodotti dai cambiamenti ambientali da inizio secolo fino ad oggi è pari a quello delle due guerre mondiali messe insieme. Alla luce di tali considerazioni e delle allarmanti previsioni di crescita della temperatura nei prossimi decenni risulta quindi urgente l'individuazione di una soluzione tecnologica ambientalmente compatibile che consenta di contrastare il riscaldamento globale nel breve termine.
An investigation on the acoustical characteristics of an electromagnetic hemianechoic room is her... more An investigation on the acoustical characteristics of an electromagnetic hemianechoic room is here proposed. The research has been carried out within an agreement between the Perugia University Acoustic Laboratory and Angelantoni Industrie S.p.a. Angelantoni Industrie hemianechoic room has been investigated. The room has been created for electromagnetic compatibility tests. It is fully insulated from the outside environment and it guarantees more than 10 KOhms of insulating power. A hybrid solution has been chosen for the anechoic lining of walls and ceiling; the 'quiet zone' is covered by 24" cones coupled to ferrite tiles whereas the remaining parts are covered with 36" cones. No fixed anechoic insulation is on the floor (hemianechoic type). An acoustic measurement campaign has been carried out in order to verify if the investigated room is characterized also by high acoustic hemianechoic performances. Measurements have been led according to ISO 3745. Measurement results have shown that the investigated room, differently from the acoustic typical hemianechoic rooms, accords to ISO 3745 only for 315-20000 Hz frequency range and for a 2.5 m radius hemispheric surface.
Per limitare le conseguenze sull'ambiente derivanti dall'aumento di consumo di combustibili fossi... more Per limitare le conseguenze sull'ambiente derivanti dall'aumento di consumo di combustibili fossili, la comunità internazionale si è rivolta a nuove soluzioni tecnologiche quali Fuel Cells (FC) e Veicoli alimentati a Celle a Combustibile (FCV) che impiegano come combustibile l'idrogeno. Tra gli ostacoli più grandi che si frappongono alla diffusione di queste nuove tecnologie ci sono però quelli legati allo stoccaggio e al trasporto dell' H 2 stesso.
Journal of The Acoustical Society of America, 2002
An original prototype for train locomotor exhaust gas pipe noise reduction (electronic muffler) i... more An original prototype for train locomotor exhaust gas pipe noise reduction (electronic muffler) is proposed: the system is based on an active noise control technique. An acoustical measurement campaign has shown that locomotor exhaust noise is characterized by very low frequency components (less than 80 Hz) and very high acoustic power (up to 110 dB). A peculiar electronic muffler characterized by high acoustical efficiency at very low frequencies has been designed and realized at Perugia University Acoustic Laboratory; it has been installed on an Italian D.245 train locomotor, equipped with a 500-kW diesel engine. The electronic muffler has been added to the traditional passive muffler. Very low transmission losses are introduced by the electronic muffler because of its particular shape; thus, engine efficiency does not further decrease. Canceling noise is generated by means of DSP-based numerical algorithm. Disturbing noise and canceling noise destructively interfere at the exhaust duct outlet section; outgoing noise is thus reduced. The control system reduces exhaust noise both in the steady and unsteady engine regime. Measurement results have shown that electronic muffler introduces up to 15 dB noise abatement in the low-frequency components.
Pipe §net" is an Italian innovative freight transport system for payloads up to 50 Kg, constitute... more Pipe §net" is an Italian innovative freight transport system for payloads up to 50 Kg, constituted by a network of vacuum-sealed pipes where goods-carrying capsules are moved by electric linear motors in very low friction conditions and at variable speed. The system is at an advanced concept stage with many researches and a feasibility study accomplished. In comparison with other systems Pipe §net focuses on small volume freight, thus avoiding many of the critical issues innovative systems meet in their development: construction complexity, overall size and interference of the new infrastructures with the territory, safety requirements of vehicles transporting both passengers and freight and/or transferring tons of goods, all of these issues affect the progress of untraditional systems due to cost, environmental impact and timing.
An original method to evaluate vibration levels due to road vehicles is proposed. A measurement c... more An original method to evaluate vibration levels due to road vehicles is proposed. A measurement campaign has been carried out to individuate vibration acceleration levels for different typologies of vehicles. Each vehicle passage has been considered as a single event. Vibration levels due to each single event have been measured by means of a data acquisition system. Measurement results allowed to individuate the relations among vibration levels, typology of vehicle, vehicle velocity and soil characteristics. Thus, acceleration levels may be estimated at different distances from the vibration source by adopting a propagation model which has been previously proposed for train induced soil vibrations .
Nel presente lavoro si propone un sistema per la climatizzazione degli ambienti abitativi basato ... more Nel presente lavoro si propone un sistema per la climatizzazione degli ambienti abitativi basato sull'effetto serra e materiali a cambiamento di fase (PCM). Il sistema è costituito da PCM opportunamente installato dietro pareti vetrate esposte alla radiazione solare; l'effetto serra consente di accumulare nelle ore diurne l'energia necessaria a bilanciare il carico termico notturno. L'ottimizzazione del sistema e la validazione delle scelte progettuali adottate sono state effettuate mediante simulazioni numeriche con un codice di calcolo ai volumi finiti. I risultati delle simulazioni hanno peraltro permesso di individuare i parametri e le condizioni operative che rendono conveniente l'impiego di tali sistemi.
Reduction methods for ultra freezers noise emissions are here studied. The investigated freezer i... more Reduction methods for ultra freezers noise emissions are here studied. The investigated freezer is the model "PLATINUM 750 V", manufactured by Angelantoni Industrie S.p.a.. An intensity and a vibration measurements campaign has been led in order to individuate freezer noise characteristics. A sound pressure measurement campaign have been also carried out for low frequency noise components determination; a comparison has been made between power levels obtained by two measurement methods: intensity and pressure level measurements. Measurements results have shown that freezer fan and compressors are the main noise sources. Thus, some vibration and acoustic insulation solutions have been proposed and realized. Noise reduction solutions performances have been verified by a measurement campaign.
operate at temperatures ranging from 600 to 700°C; high temperatures allow to obtain low internal... more operate at temperatures ranging from 600 to 700°C; high temperatures allow to obtain low internal losses with large benefits in terms of generated electric power. A new geometry for small sized MCFCs is proposed in this paper. Cell thermofluidodynamic performance has been analyzed through a numerical code. Simulation results verified the suitability of the proposed cell design solutions. A stack consisting of three elementary units has been created in order to experimentally evaluate the proposed cell performance.
L'incremento della temperatura media della Terra sia esso dovuto a cause naturali che antropiche ... more L'incremento della temperatura media della Terra sia esso dovuto a cause naturali che antropiche è un fatto ormai condiviso da tutta la comunità scientifica. Le conseguenze dell'incremento della temperatura sono evidenti: innalzamento del livello degli oceani, scioglimento dei ghiacci, desertificazione, eventi meteorologici estremi, etc.. Le conseguenze sociali, economiche e politiche sono altrettanto preoccupanti. Studi recenti hanno stimato che l'entità dei danni prodotti dai cambiamenti ambientali da inizio secolo fino ad oggi è pari a quello delle due guerre mondiali messe insieme. Alla luce di tali considerazioni e delle allarmanti previsioni di crescita della temperatura nei prossimi decenni risulta quindi urgente l'individuazione di una soluzione tecnologica ambientalmente compatibile che consenta di contrastare il riscaldamento globale nel breve termine.
Fin spacing is chosen to maximize heat transmission rate. Maximization is attained as a compromis... more Fin spacing is chosen to maximize heat transmission rate. Maximization is attained as a compromise between two opposite trends: fin surface maximization and adduction coefficient maximization. In this paper a new relation for the optimum spacing between rectangular fins is proposed. The relation was obtained keeping into account non-unitary fin efficiency. Demonstration is achieved by a theoretical approach which regards only rectangular fins. Results were verified also by numerical simulations. An original method to evaluate radiative heat flux is proposed too. The method allows to obtain an original simple radiative heat flux equation. Numerical simulations and theoretical evaluations show that the proposed convective flux optimization method and the model for radiative flux estimation are respectively suitable for high length and high temperature rectangular fins. 4 3 2 1 J J J J dA e T a J J J J
Per limitare le conseguenze sull'ambiente derivanti dall'aumento di consumo di combustibili fossi... more Per limitare le conseguenze sull'ambiente derivanti dall'aumento di consumo di combustibili fossili, la comunità internazionale si è rivolta a nuove soluzioni tecnologiche quali Fuel Cells (FC) e Veicoli alimentati a Celle a Combustibile (FCV) che impiegano come combustibile l'idrogeno. Tra gli ostacoli più grandi che si frappongono alla diffusione di queste nuove tecnologie ci sono però quelli legati allo stoccaggio e al trasporto dell' H 2 stesso.
In this paper an innovative concrete and inert mixture is proposed to assemble building partition... more In this paper an innovative concrete and inert mixture is proposed to assemble building partition walls. Mixture is made for no-structural light concrete by aggregating concrete with natural and artificial inerts. Pumice, lapillus and rubber are employed as inerts. A measurement campaign was carried out to evaluate the materials acoustic properties for different samples composition. Experimental tests were realized by an impedance tube: transmission loss was evaluated by a four microphone transfer function method, based on ISO 10534-2. Test results are here reported. Measurements results allows to determine the optimum mixture in term of acoustic properties.
Pipe §net" is an Italian innovative freight transport system for payloads up to 50 Kg, constitute... more Pipe §net" is an Italian innovative freight transport system for payloads up to 50 Kg, constituted by a network of vacuum-sealed pipes where goods-carrying capsules are moved by electric linear motors in very low friction conditions and at variable speed. The system is at an advanced concept stage with many researches and a feasibility study accomplished. In comparison with other systems Pipe §net focuses on small volume freight, thus avoiding many of the critical issues innovative systems meet in their development: construction complexity, overall size and interference of the new infrastructures with the territory, safety requirements of vehicles transporting both passengers and freight and/or transferring tons of goods, all of these issues affect the progress of untraditional systems due to cost, environmental impact and timing.
This paper deals with an experimental investigation on water photosonolysis for hydrogen producti... more This paper deals with an experimental investigation on water photosonolysis for hydrogen production. Water splitting is obtained by superposition of photolysis and sonolysis phenomena (photosonolysis) which are induced by the combined action of sunlight and ultrasounds. An experimental device was realized to investigate such phenomena; experimental tests were carried out: hydrogen production increases linearly with time; besides, hydrogen production dims as pressure increases. Thus, the proposed method suggests further investigations focused to test improvements on ultrasound-water matching and sunlight catalyst; a new reactor will be designed which is characterized by innovative systems for hydrogen separation.
Nel presente lavoro si propone un sistema per la climatizzazione degli ambienti abitativi basato ... more Nel presente lavoro si propone un sistema per la climatizzazione degli ambienti abitativi basato sull'effetto serra e materiali a cambiamento di fase (PCM). Il sistema è costituito da PCM opportunamente installato dietro pareti vetrate esposte alla radiazione solare; l'effetto serra consente di accumulare nelle ore diurne l'energia necessaria a bilanciare il carico termico notturno. L'ottimizzazione del sistema e la validazione delle scelte progettuali adottate sono state effettuate mediante simulazioni numeriche con un codice di calcolo ai volumi finiti. I risultati delle simulazioni hanno peraltro permesso di individuare i parametri e le condizioni operative che rendono conveniente l'impiego di tali sistemi.
An investigation on the acoustical characteristics of an electromagnetic hemianechoic room is her... more An investigation on the acoustical characteristics of an electromagnetic hemianechoic room is here proposed. The research has been carried out within an agreement between the Perugia University Acoustic Laboratory and Angelantoni Industrie S.p.a. Angelantoni Industrie hemianechoic room has been investigated. The room has been created for electromagnetic compatibility tests. It is fully insulated from the outside environment and it guarantees more than 10 KOhms of insulating power. A hybrid solution has been chosen for the anechoic lining of walls and ceiling; the 'quiet zone' is covered by 24" cones coupled to ferrite tiles whereas the remaining parts are covered with 36" cones. No fixed anechoic insulation is on the floor (hemianechoic type). An acoustic measurement campaign has been carried out in order to verify if the investigated room is characterized also by high acoustic hemianechoic performances. Measurements have been led according to ISO 3745. Measurement results have shown that the investigated room, differently from the acoustic typical hemianechoic rooms, accords to ISO 3745 only for 315-20000 Hz frequency range and for a 2.5 m radius hemispheric surface.
Journal of The Acoustical Society of America, 2002
An original prototype for train locomotor exhaust gas pipe noise reduction (electronic muffler) i... more An original prototype for train locomotor exhaust gas pipe noise reduction (electronic muffler) is proposed: the system is based on an active noise control technique. An acoustical measurement campaign has shown that locomotor exhaust noise is characterized by very low frequency components (less than 80 Hz) and very high acoustic power (up to 110 dB). A peculiar electronic muffler characterized by high acoustical efficiency at very low frequencies has been designed and realized at Perugia University Acoustic Laboratory; it has been installed on an Italian D.245 train locomotor, equipped with a 500-kW diesel engine. The electronic muffler has been added to the traditional passive muffler. Very low transmission losses are introduced by the electronic muffler because of its particular shape; thus, engine efficiency does not further decrease. Canceling noise is generated by means of DSP-based numerical algorithm. Disturbing noise and canceling noise destructively interfere at the exhaust duct outlet section; outgoing noise is thus reduced. The control system reduces exhaust noise both in the steady and unsteady engine regime. Measurement results have shown that electronic muffler introduces up to 15 dB noise abatement in the low-frequency components.
An original method to evaluate vibration levels due to road vehicles is proposed. A measurement c... more An original method to evaluate vibration levels due to road vehicles is proposed. A measurement campaign has been carried out to individuate vibration acceleration levels for different typologies of vehicles. Each vehicle passage has been considered as a single event. Vibration levels due to each single event have been measured by means of a data acquisition system. Measurement results allowed to individuate the relations among vibration levels, typology of vehicle, vehicle velocity and soil characteristics. Thus, acceleration levels may be estimated at different distances from the vibration source by adopting a propagation model which has been previously proposed for train induced soil vibrations .
Reduction methods for ultra freezers noise emissions are here studied. The investigated freezer i... more Reduction methods for ultra freezers noise emissions are here studied. The investigated freezer is the model "PLATINUM 750 V", manufactured by Angelantoni Industrie S.p.a.. An intensity and a vibration measurements campaign has been led in order to individuate freezer noise characteristics. A sound pressure measurement campaign have been also carried out for low frequency noise components determination; a comparison has been made between power levels obtained by two measurement methods: intensity and pressure level measurements. Measurements results have shown that freezer fan and compressors are the main noise sources. Thus, some vibration and acoustic insulation solutions have been proposed and realized. Noise reduction solutions performances have been verified by a measurement campaign.
L'incremento della temperatura media della Terra sia esso dovuto a cause naturali che antropiche ... more L'incremento della temperatura media della Terra sia esso dovuto a cause naturali che antropiche è un fatto ormai condiviso da tutta la comunità scientifica. Le conseguenze dell'incremento della temperatura sono evidenti: innalzamento del livello degli oceani, scioglimento dei ghiacci, desertificazione, eventi meteorologici estremi, etc.. Le conseguenze sociali, economiche e politiche sono altrettanto preoccupanti. Studi recenti hanno stimato che l'entità dei danni prodotti dai cambiamenti ambientali da inizio secolo fino ad oggi è pari a quello delle due guerre mondiali messe insieme. Alla luce di tali considerazioni e delle allarmanti previsioni di crescita della temperatura nei prossimi decenni risulta quindi urgente l'individuazione di una soluzione tecnologica ambientalmente compatibile che consenta di contrastare il riscaldamento globale nel breve termine.
An investigation on the acoustical characteristics of an electromagnetic hemianechoic room is her... more An investigation on the acoustical characteristics of an electromagnetic hemianechoic room is here proposed. The research has been carried out within an agreement between the Perugia University Acoustic Laboratory and Angelantoni Industrie S.p.a. Angelantoni Industrie hemianechoic room has been investigated. The room has been created for electromagnetic compatibility tests. It is fully insulated from the outside environment and it guarantees more than 10 KOhms of insulating power. A hybrid solution has been chosen for the anechoic lining of walls and ceiling; the 'quiet zone' is covered by 24" cones coupled to ferrite tiles whereas the remaining parts are covered with 36" cones. No fixed anechoic insulation is on the floor (hemianechoic type). An acoustic measurement campaign has been carried out in order to verify if the investigated room is characterized also by high acoustic hemianechoic performances. Measurements have been led according to ISO 3745. Measurement results have shown that the investigated room, differently from the acoustic typical hemianechoic rooms, accords to ISO 3745 only for 315-20000 Hz frequency range and for a 2.5 m radius hemispheric surface.
Per limitare le conseguenze sull'ambiente derivanti dall'aumento di consumo di combustibili fossi... more Per limitare le conseguenze sull'ambiente derivanti dall'aumento di consumo di combustibili fossili, la comunità internazionale si è rivolta a nuove soluzioni tecnologiche quali Fuel Cells (FC) e Veicoli alimentati a Celle a Combustibile (FCV) che impiegano come combustibile l'idrogeno. Tra gli ostacoli più grandi che si frappongono alla diffusione di queste nuove tecnologie ci sono però quelli legati allo stoccaggio e al trasporto dell' H 2 stesso.
Journal of The Acoustical Society of America, 2002
An original prototype for train locomotor exhaust gas pipe noise reduction (electronic muffler) i... more An original prototype for train locomotor exhaust gas pipe noise reduction (electronic muffler) is proposed: the system is based on an active noise control technique. An acoustical measurement campaign has shown that locomotor exhaust noise is characterized by very low frequency components (less than 80 Hz) and very high acoustic power (up to 110 dB). A peculiar electronic muffler characterized by high acoustical efficiency at very low frequencies has been designed and realized at Perugia University Acoustic Laboratory; it has been installed on an Italian D.245 train locomotor, equipped with a 500-kW diesel engine. The electronic muffler has been added to the traditional passive muffler. Very low transmission losses are introduced by the electronic muffler because of its particular shape; thus, engine efficiency does not further decrease. Canceling noise is generated by means of DSP-based numerical algorithm. Disturbing noise and canceling noise destructively interfere at the exhaust duct outlet section; outgoing noise is thus reduced. The control system reduces exhaust noise both in the steady and unsteady engine regime. Measurement results have shown that electronic muffler introduces up to 15 dB noise abatement in the low-frequency components.
Pipe §net" is an Italian innovative freight transport system for payloads up to 50 Kg, constitute... more Pipe §net" is an Italian innovative freight transport system for payloads up to 50 Kg, constituted by a network of vacuum-sealed pipes where goods-carrying capsules are moved by electric linear motors in very low friction conditions and at variable speed. The system is at an advanced concept stage with many researches and a feasibility study accomplished. In comparison with other systems Pipe §net focuses on small volume freight, thus avoiding many of the critical issues innovative systems meet in their development: construction complexity, overall size and interference of the new infrastructures with the territory, safety requirements of vehicles transporting both passengers and freight and/or transferring tons of goods, all of these issues affect the progress of untraditional systems due to cost, environmental impact and timing.
An original method to evaluate vibration levels due to road vehicles is proposed. A measurement c... more An original method to evaluate vibration levels due to road vehicles is proposed. A measurement campaign has been carried out to individuate vibration acceleration levels for different typologies of vehicles. Each vehicle passage has been considered as a single event. Vibration levels due to each single event have been measured by means of a data acquisition system. Measurement results allowed to individuate the relations among vibration levels, typology of vehicle, vehicle velocity and soil characteristics. Thus, acceleration levels may be estimated at different distances from the vibration source by adopting a propagation model which has been previously proposed for train induced soil vibrations .
Nel presente lavoro si propone un sistema per la climatizzazione degli ambienti abitativi basato ... more Nel presente lavoro si propone un sistema per la climatizzazione degli ambienti abitativi basato sull'effetto serra e materiali a cambiamento di fase (PCM). Il sistema è costituito da PCM opportunamente installato dietro pareti vetrate esposte alla radiazione solare; l'effetto serra consente di accumulare nelle ore diurne l'energia necessaria a bilanciare il carico termico notturno. L'ottimizzazione del sistema e la validazione delle scelte progettuali adottate sono state effettuate mediante simulazioni numeriche con un codice di calcolo ai volumi finiti. I risultati delle simulazioni hanno peraltro permesso di individuare i parametri e le condizioni operative che rendono conveniente l'impiego di tali sistemi.
Reduction methods for ultra freezers noise emissions are here studied. The investigated freezer i... more Reduction methods for ultra freezers noise emissions are here studied. The investigated freezer is the model "PLATINUM 750 V", manufactured by Angelantoni Industrie S.p.a.. An intensity and a vibration measurements campaign has been led in order to individuate freezer noise characteristics. A sound pressure measurement campaign have been also carried out for low frequency noise components determination; a comparison has been made between power levels obtained by two measurement methods: intensity and pressure level measurements. Measurements results have shown that freezer fan and compressors are the main noise sources. Thus, some vibration and acoustic insulation solutions have been proposed and realized. Noise reduction solutions performances have been verified by a measurement campaign.
operate at temperatures ranging from 600 to 700°C; high temperatures allow to obtain low internal... more operate at temperatures ranging from 600 to 700°C; high temperatures allow to obtain low internal losses with large benefits in terms of generated electric power. A new geometry for small sized MCFCs is proposed in this paper. Cell thermofluidodynamic performance has been analyzed through a numerical code. Simulation results verified the suitability of the proposed cell design solutions. A stack consisting of three elementary units has been created in order to experimentally evaluate the proposed cell performance.
L'incremento della temperatura media della Terra sia esso dovuto a cause naturali che antropiche ... more L'incremento della temperatura media della Terra sia esso dovuto a cause naturali che antropiche è un fatto ormai condiviso da tutta la comunità scientifica. Le conseguenze dell'incremento della temperatura sono evidenti: innalzamento del livello degli oceani, scioglimento dei ghiacci, desertificazione, eventi meteorologici estremi, etc.. Le conseguenze sociali, economiche e politiche sono altrettanto preoccupanti. Studi recenti hanno stimato che l'entità dei danni prodotti dai cambiamenti ambientali da inizio secolo fino ad oggi è pari a quello delle due guerre mondiali messe insieme. Alla luce di tali considerazioni e delle allarmanti previsioni di crescita della temperatura nei prossimi decenni risulta quindi urgente l'individuazione di una soluzione tecnologica ambientalmente compatibile che consenta di contrastare il riscaldamento globale nel breve termine.
Fin spacing is chosen to maximize heat transmission rate. Maximization is attained as a compromis... more Fin spacing is chosen to maximize heat transmission rate. Maximization is attained as a compromise between two opposite trends: fin surface maximization and adduction coefficient maximization. In this paper a new relation for the optimum spacing between rectangular fins is proposed. The relation was obtained keeping into account non-unitary fin efficiency. Demonstration is achieved by a theoretical approach which regards only rectangular fins. Results were verified also by numerical simulations. An original method to evaluate radiative heat flux is proposed too. The method allows to obtain an original simple radiative heat flux equation. Numerical simulations and theoretical evaluations show that the proposed convective flux optimization method and the model for radiative flux estimation are respectively suitable for high length and high temperature rectangular fins. 4 3 2 1 J J J J dA e T a J J J J
Per limitare le conseguenze sull'ambiente derivanti dall'aumento di consumo di combustibili fossi... more Per limitare le conseguenze sull'ambiente derivanti dall'aumento di consumo di combustibili fossili, la comunità internazionale si è rivolta a nuove soluzioni tecnologiche quali Fuel Cells (FC) e Veicoli alimentati a Celle a Combustibile (FCV) che impiegano come combustibile l'idrogeno. Tra gli ostacoli più grandi che si frappongono alla diffusione di queste nuove tecnologie ci sono però quelli legati allo stoccaggio e al trasporto dell' H 2 stesso.
In this paper an innovative concrete and inert mixture is proposed to assemble building partition... more In this paper an innovative concrete and inert mixture is proposed to assemble building partition walls. Mixture is made for no-structural light concrete by aggregating concrete with natural and artificial inerts. Pumice, lapillus and rubber are employed as inerts. A measurement campaign was carried out to evaluate the materials acoustic properties for different samples composition. Experimental tests were realized by an impedance tube: transmission loss was evaluated by a four microphone transfer function method, based on ISO 10534-2. Test results are here reported. Measurements results allows to determine the optimum mixture in term of acoustic properties.
Pipe §net" is an Italian innovative freight transport system for payloads up to 50 Kg, constitute... more Pipe §net" is an Italian innovative freight transport system for payloads up to 50 Kg, constituted by a network of vacuum-sealed pipes where goods-carrying capsules are moved by electric linear motors in very low friction conditions and at variable speed. The system is at an advanced concept stage with many researches and a feasibility study accomplished. In comparison with other systems Pipe §net focuses on small volume freight, thus avoiding many of the critical issues innovative systems meet in their development: construction complexity, overall size and interference of the new infrastructures with the territory, safety requirements of vehicles transporting both passengers and freight and/or transferring tons of goods, all of these issues affect the progress of untraditional systems due to cost, environmental impact and timing.
This paper deals with an experimental investigation on water photosonolysis for hydrogen producti... more This paper deals with an experimental investigation on water photosonolysis for hydrogen production. Water splitting is obtained by superposition of photolysis and sonolysis phenomena (photosonolysis) which are induced by the combined action of sunlight and ultrasounds. An experimental device was realized to investigate such phenomena; experimental tests were carried out: hydrogen production increases linearly with time; besides, hydrogen production dims as pressure increases. Thus, the proposed method suggests further investigations focused to test improvements on ultrasound-water matching and sunlight catalyst; a new reactor will be designed which is characterized by innovative systems for hydrogen separation.
Nel presente lavoro si propone un sistema per la climatizzazione degli ambienti abitativi basato ... more Nel presente lavoro si propone un sistema per la climatizzazione degli ambienti abitativi basato sull'effetto serra e materiali a cambiamento di fase (PCM). Il sistema è costituito da PCM opportunamente installato dietro pareti vetrate esposte alla radiazione solare; l'effetto serra consente di accumulare nelle ore diurne l'energia necessaria a bilanciare il carico termico notturno. L'ottimizzazione del sistema e la validazione delle scelte progettuali adottate sono state effettuate mediante simulazioni numeriche con un codice di calcolo ai volumi finiti. I risultati delle simulazioni hanno peraltro permesso di individuare i parametri e le condizioni operative che rendono conveniente l'impiego di tali sistemi.
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Papers by Franco Cotana