Kees de Blok - Academia.edu (original) (raw)

Papers by Kees de Blok

Research paper thumbnail of On the design of near atmospheric air operated thermoacoustic engines

Conversion of heat (from primary energy sources) into a higher form of energy, like mechanical po... more Conversion of heat (from primary energy sources) into a higher form of energy, like mechanical power or electricity, is one of the oldest and most wide spread underlying technologies supporting nearly all our modern infrastructure, communication and social activities which in their turn are recognized as essential ingredients for prosperity. Therefore, The availability of devices for small scale conversion of heat into electricity could contribute to the improvement of living conditions in rural areas and developing countries.

Research paper thumbnail of A coherent optical system for analogue multichannel video transmission

A heterodyne analogue system using optical phase modulation is well suited for analogue transmiss... more A heterodyne analogue system using optical phase modulation is well suited for analogue transmission of CATV signals with a large number of videochannels. The authors describe the realisation of a heterodyne transmission system using optical phase modulation and nonsynchronous demodulation. In the experimental setup 18 standard FDM multiplexed TV channels (PAL system) are modulated onto a single optical carrier; the system concept allows transmission of 30 channels. The power budget allows a further increase in capacity by using multiple (at least 10) optical carriers in optical FDM, each carrying 30 TV channels. In order to meet the stringent phase noise requirements, two novel concepts are presented for phase noise reduction: optical filtering and phase-noise compensation based on linear heterodyne detection. For reduction of the required receiver bandwidth, a new detection scheme has been developed, offering simultaneous phase diversity, intensity noise suppression and frequency ...

Research paper thumbnail of Direct-reading one-port acoustic network analyzer

Journal of The Audio Engineering Society, 1993

A novel measurement instrument is proposed to perform reflection measurements of guided acoustic ... more A novel measurement instrument is proposed to perform reflection measurements of guided acoustic waves. Both the magnitude and the phase of the reflection coefficient are measured simultaneously. The compact construction and the direct readout feature facilitate an attractive measurement alternative for traditional standing wave ratio detectors with movable microphones. These adwantages are decisive for infrasonic frequencies

Research paper thumbnail of Full Characterization of Linear Acoustic Networks Based on N-Ports and S Parameters

Journal of The Audio Engineering Society, 1992

Research paper thumbnail of Thermo-akoestische systemen voor het opwaarderen van industriële restwarmte Openbare eindrapportage EOS-LT04022

Dit document bevat de openbare rapportage van het project "thermo-akoestische systemen voor ... more Dit document bevat de openbare rapportage van het project "thermo-akoestische systemen voor het opwaarderen van restwarmte (TASOR)". Het project is uigevoerd met subsidie van het Ministerie van Economische Zaken, regeling EOS: Lange Termijn, uitgevoerd door SenterNovem. Het project staat bij EOS-LT bekend onder het projectnummer EOSLT04022.

Research paper thumbnail of The analysis of hybrid solar powered cooling/heating system with the travelling-wave thermoacoustic refrigerator

Proceedings of the 3rd International Workshop on Thermoacoustics, 2015

Research paper thumbnail of Details and experimental results of a stand-alone container cooled by a solar driven multi-stage traveling wave thermoacoustic system

3rd international workshop on thermoacoustics, University of Twente, 26-27 October 2015, 2015

Research paper thumbnail of High-dynamic-range heterodyne measurement of optical spectra

Optics Letters, 1991

The dynamic range of a conventional heterodyne spectroscope is limited by the intensity noise and... more The dynamic range of a conventional heterodyne spectroscope is limited by the intensity noise and the shot noise of the optical spectrum under test. We propose to improve the dynamic range by several orders of magnitude by using phase-sensitive detection. We demonstrate the feasibility of our method by measuring the tails of a distributedfeedback laser line 60 dB below maximum, which gave an improvement of 35 dB compared with that of the conventional technique: 15 dB by using a balanced receiver and another 20 dB by the phase-sensitive detection.

Research paper thumbnail of Core alignment procedure for single-mode-fibre jointing

Electronics Letters, 1984

Indexing term: Optical fibres An auxiliary optical system is described which will enable the core... more Indexing term: Optical fibres An auxiliary optical system is described which will enable the core alignment of single-mode fibres in a jointing location without use of far-end apparatus. The system is based on the launching of an optical signal into the core of the first fibre and the detection of this signal from the core of the second fibre by bending of the fibres and without removal of the coating. A two-step experimental alignment procedure is described consisting of a visual coarse alignment followed by a fine alignment by means of a simple piezo-electric fibre translator.

Research paper thumbnail of Field measurement of splice loss applying the backscattering method

Electronics Letters, 1979

Step-index multimode 60 8-5 21-7 AlGaAs/GaAs 0-85 Si a.p.d.-26-3 51 5 2-4 Experiment 2 Single-mod... more Step-index multimode 60 8-5 21-7 AlGaAs/GaAs 0-85 Si a.p.d.-26-3 51 5 2-4 Experiment 2 Single-mode 61 8-2 29-4 AlGaAs/GaAs 0-85 Si a.p.d.-36-3 42 2 0-5 Experiment 3 Single-mode 11 32-0 21-3 InGaAsP/InP 1 29 Ge a.p.d.

Research paper thumbnail of Optical fiber power-splitter with selectable splitting ratio

Applied Optics, 1982

An optical fiber power-splitter using a thin phase grating is described. Special attention is pai... more An optical fiber power-splitter using a thin phase grating is described. Special attention is paid to the wave-length dependency, the insertion loss, and the splitting ratio. By feedback of the output signal, a variety of splitting ratios can be obtained despite the use of a very simple (but highly efficient) grating with a low splitting factor. Experiments were performed with a simple nonoptimal biphase grating confirming the theoretical description. Double passing of the grating results in a selectable splitting ratio of 3, 5, 7, or 9 with a nonuniform power-level distribution for the splitting ratios 5 and 7. Wavelength dependency is hardly restrictive for the applications that can be foreseen for these devices.

Research paper thumbnail of <title>Phase Noise Suppression In Coherent Optical Communication Systems By Differential Modulation</title>

Coherent Lightwave Communications: Fourth in a Series, 1990

Two novel concepts for suppression of laser phase noise in coherent optical communication systems... more Two novel concepts for suppression of laser phase noise in coherent optical communication systems are presented, based on compensation after heterodyne detection. As a result, the normally imposed requirements on laser linewidth to bit rate ratio can be diminished considerably. Discussion of both techniques is given, together with computer simulations and experiments demonstrating the principles of operation.

Research paper thumbnail of Proceedings of the 3rd International Workshop on Thermoacoustics : 26-27 October, 2015, University of Twente, The Netherlands

Thermoacoustic refrigeration systems: recent developments TS02 Paweł Owczarek Details and experim... more Thermoacoustic refrigeration systems: recent developments TS02 Paweł Owczarek Details and experimental results of a stand-alone container cooled by a solar driven multi-stage traveling wave thermoacoustic system TS04 Chris Lawn Optimization of the loop in a travelling-wave thermo-acoustic engine TS05 Maurice-Xavier Francois The VALTA project: full scale conversion of CHP engine flue gas heat into electricity 12:20 13:20 Lunch Grand café 13:20 14:40 Session 2a Erlenmeyer AE05 Douglas Wilcox Development of a compact thermoacoustic-Stirling electric generator AE02 Jeffrey Lin High-fidelity simulations of a standing-wave thermoacousticpiezoelectric engine AE04 Bakhtier Farouk Signal conditioning of carbon nanotube loudspeaker AE01 Ken Kaneuchi Evaluation of bi-directional turbines using the two-sensor method 14:40 14:50 Coffee The Gallery 14:50 16:10 Session 3a Erlenmeyer AE03 Johan Brussen Modeling and controlling the generator of a thermoacoustic Stirling engine AE06 Maurice-Xavier Francois Space thermoacoustic radio-isotopic power system: SpaceTRIPS TS15 Hiroaki Hyodo Dynamics of forced synchronization in thermoacoustic system 16:10 16:20 Coffee The Gallery 16:20 17:20 Session 4a Erlenmeyer TC01 Marialuisa Napolitano The role of stack non acoustic parameters on thermodynamic performance of standing wave devices TC02 Esmatullah Maiwand Sharify CFD study of oscillatory flow around parallel plates in a traveling-wave thermoacoustic engine

Research paper thumbnail of Towards the application of thermoacoustic cooling in office buildings : performance governing parameters and models for performance predictions

Solar assisted thermoacoustic cooling is with the recent advances in energy conversion efficiency... more Solar assisted thermoacoustic cooling is with the recent advances in energy conversion efficiency an interesting alternative to sorption based technologies. Although thermoacoustic cooling is characterized with a slightly reduced COP, is has the advantage to require little to no maintenance and has zero global warming potential. To successfully use the technology to cool office buildings an optimally designed machine and a careful building integration is required. To assess the integrated performance of building, thermoacoustic cooler and heat rejection system, the authors propose to use building and system performance simulation tools. However, there are no component models readily available to model a thermoacoustic cooler within those environments. In this contribution the authors aim to determine the needed modelling complexity level for a component model of a thermoacoustic cooler. As the energy conversion efficiencies are sensitive to geometrical and operational parameter of t...

Research paper thumbnail of Implementing a bidirectional impulse turbine into a thermoacoustic refrigerator

The Journal of the Acoustical Society of America, 2020

Research paper thumbnail of Review on the conversion of thermoacoustic power into electricity

The Journal of the Acoustical Society of America, 2018

Thermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently in... more Thermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently into electric power. This article provides a review of the four main methods to convert the (thermo)acoustic power into electricity. First, loudspeakers and linear alternators are discussed in a section on electromagnetic devices. This is followed by sections on piezoelectric transducers, magnetohydrodynamic generators, and bidirectional turbines. Each segment provides a literature review of the given technology for the field of thermoacoustics, focusing on possible configurations, operating characteristics, output performance, and analytical and numerical methods to study the devices. This information is used as an input to discuss the performance and feasibility of each method, and to identify challenges that should be overcome for a more successful implementation in thermoacoustic engines. The work is concluded by a comparison of the four technologies, concentrating on the possible area...

Research paper thumbnail of The VALTA project: Full scale conversion of CHP engine flue gas heat into electricity

Proceedings of the 3rd International Workshop on Thermoacoustics, 2015

Research paper thumbnail of Space thermoacoustic radio-isotopic power system: SpaceTRIPS

Proceedings of the 3rd International Workshop on Thermoacoustics, 2015

Research paper thumbnail of Novel 4-Stage Traveling Wave Thermoacoustic Power Generator

ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting: Volume 2, Fora, 2010

Utilizing low temperature differences from solar vacuum tube collectors or waste heat in the rang... more Utilizing low temperature differences from solar vacuum tube collectors or waste heat in the range 70–200 °C seems to be the most promising and commercial interesting field of applications for thermoacoustic systems. Recently a novel 4-stage “self matching” traveling wave engine is developed and tested. Beside the low acoustic loss and compactness, due to traveling wave feedback, all components per stage are identical which is beneficial from (mass) production point of view. Based on this concept a 100 kWT thermoacoustic power (TAP) generator is under construction. This project is carried out in the framework of phase two of the Dutch SBIR program. The 100 kWT TAP will be installed at a paper manufacturing plant in the Netherlands for converting part of the flue gas at 150°C from the paper drying process into electricity. Emphasis in this project is on production and cost aspects lowering the investment per kWe to a level competitive to ORC’s. After successful completion of this pil...

Research paper thumbnail of COSNET-a coherent optical subscriber network

Journal of Lightwave Technology, 1993

A complete coherent multi-channel system, designed for application in the local loop is presented... more A complete coherent multi-channel system, designed for application in the local loop is presented. The concept and the technical realization of a uni-and bi-directional system in a laboratory demonstrator are described. The realized network control, including frequency management of the bi-directional channels, and network security are discussed. Attention is paid to the evolution scenario from a narrow band to a complete broad-band system. All aspects are integrated in a demonstrator, which is capable of supporting a large number of narrow-band and broad-band distributive and communicative services. Several novel technical solutions (for frequency management, data induced polarization switching (DIPS), high-speed encryption and network signalling) are presented.

Research paper thumbnail of On the design of near atmospheric air operated thermoacoustic engines

Conversion of heat (from primary energy sources) into a higher form of energy, like mechanical po... more Conversion of heat (from primary energy sources) into a higher form of energy, like mechanical power or electricity, is one of the oldest and most wide spread underlying technologies supporting nearly all our modern infrastructure, communication and social activities which in their turn are recognized as essential ingredients for prosperity. Therefore, The availability of devices for small scale conversion of heat into electricity could contribute to the improvement of living conditions in rural areas and developing countries.

Research paper thumbnail of A coherent optical system for analogue multichannel video transmission

A heterodyne analogue system using optical phase modulation is well suited for analogue transmiss... more A heterodyne analogue system using optical phase modulation is well suited for analogue transmission of CATV signals with a large number of videochannels. The authors describe the realisation of a heterodyne transmission system using optical phase modulation and nonsynchronous demodulation. In the experimental setup 18 standard FDM multiplexed TV channels (PAL system) are modulated onto a single optical carrier; the system concept allows transmission of 30 channels. The power budget allows a further increase in capacity by using multiple (at least 10) optical carriers in optical FDM, each carrying 30 TV channels. In order to meet the stringent phase noise requirements, two novel concepts are presented for phase noise reduction: optical filtering and phase-noise compensation based on linear heterodyne detection. For reduction of the required receiver bandwidth, a new detection scheme has been developed, offering simultaneous phase diversity, intensity noise suppression and frequency ...

Research paper thumbnail of Direct-reading one-port acoustic network analyzer

Journal of The Audio Engineering Society, 1993

A novel measurement instrument is proposed to perform reflection measurements of guided acoustic ... more A novel measurement instrument is proposed to perform reflection measurements of guided acoustic waves. Both the magnitude and the phase of the reflection coefficient are measured simultaneously. The compact construction and the direct readout feature facilitate an attractive measurement alternative for traditional standing wave ratio detectors with movable microphones. These adwantages are decisive for infrasonic frequencies

Research paper thumbnail of Full Characterization of Linear Acoustic Networks Based on N-Ports and S Parameters

Journal of The Audio Engineering Society, 1992

Research paper thumbnail of Thermo-akoestische systemen voor het opwaarderen van industriële restwarmte Openbare eindrapportage EOS-LT04022

Dit document bevat de openbare rapportage van het project "thermo-akoestische systemen voor ... more Dit document bevat de openbare rapportage van het project "thermo-akoestische systemen voor het opwaarderen van restwarmte (TASOR)". Het project is uigevoerd met subsidie van het Ministerie van Economische Zaken, regeling EOS: Lange Termijn, uitgevoerd door SenterNovem. Het project staat bij EOS-LT bekend onder het projectnummer EOSLT04022.

Research paper thumbnail of The analysis of hybrid solar powered cooling/heating system with the travelling-wave thermoacoustic refrigerator

Proceedings of the 3rd International Workshop on Thermoacoustics, 2015

Research paper thumbnail of Details and experimental results of a stand-alone container cooled by a solar driven multi-stage traveling wave thermoacoustic system

3rd international workshop on thermoacoustics, University of Twente, 26-27 October 2015, 2015

Research paper thumbnail of High-dynamic-range heterodyne measurement of optical spectra

Optics Letters, 1991

The dynamic range of a conventional heterodyne spectroscope is limited by the intensity noise and... more The dynamic range of a conventional heterodyne spectroscope is limited by the intensity noise and the shot noise of the optical spectrum under test. We propose to improve the dynamic range by several orders of magnitude by using phase-sensitive detection. We demonstrate the feasibility of our method by measuring the tails of a distributedfeedback laser line 60 dB below maximum, which gave an improvement of 35 dB compared with that of the conventional technique: 15 dB by using a balanced receiver and another 20 dB by the phase-sensitive detection.

Research paper thumbnail of Core alignment procedure for single-mode-fibre jointing

Electronics Letters, 1984

Indexing term: Optical fibres An auxiliary optical system is described which will enable the core... more Indexing term: Optical fibres An auxiliary optical system is described which will enable the core alignment of single-mode fibres in a jointing location without use of far-end apparatus. The system is based on the launching of an optical signal into the core of the first fibre and the detection of this signal from the core of the second fibre by bending of the fibres and without removal of the coating. A two-step experimental alignment procedure is described consisting of a visual coarse alignment followed by a fine alignment by means of a simple piezo-electric fibre translator.

Research paper thumbnail of Field measurement of splice loss applying the backscattering method

Electronics Letters, 1979

Step-index multimode 60 8-5 21-7 AlGaAs/GaAs 0-85 Si a.p.d.-26-3 51 5 2-4 Experiment 2 Single-mod... more Step-index multimode 60 8-5 21-7 AlGaAs/GaAs 0-85 Si a.p.d.-26-3 51 5 2-4 Experiment 2 Single-mode 61 8-2 29-4 AlGaAs/GaAs 0-85 Si a.p.d.-36-3 42 2 0-5 Experiment 3 Single-mode 11 32-0 21-3 InGaAsP/InP 1 29 Ge a.p.d.

Research paper thumbnail of Optical fiber power-splitter with selectable splitting ratio

Applied Optics, 1982

An optical fiber power-splitter using a thin phase grating is described. Special attention is pai... more An optical fiber power-splitter using a thin phase grating is described. Special attention is paid to the wave-length dependency, the insertion loss, and the splitting ratio. By feedback of the output signal, a variety of splitting ratios can be obtained despite the use of a very simple (but highly efficient) grating with a low splitting factor. Experiments were performed with a simple nonoptimal biphase grating confirming the theoretical description. Double passing of the grating results in a selectable splitting ratio of 3, 5, 7, or 9 with a nonuniform power-level distribution for the splitting ratios 5 and 7. Wavelength dependency is hardly restrictive for the applications that can be foreseen for these devices.

Research paper thumbnail of <title>Phase Noise Suppression In Coherent Optical Communication Systems By Differential Modulation</title>

Coherent Lightwave Communications: Fourth in a Series, 1990

Two novel concepts for suppression of laser phase noise in coherent optical communication systems... more Two novel concepts for suppression of laser phase noise in coherent optical communication systems are presented, based on compensation after heterodyne detection. As a result, the normally imposed requirements on laser linewidth to bit rate ratio can be diminished considerably. Discussion of both techniques is given, together with computer simulations and experiments demonstrating the principles of operation.

Research paper thumbnail of Proceedings of the 3rd International Workshop on Thermoacoustics : 26-27 October, 2015, University of Twente, The Netherlands

Thermoacoustic refrigeration systems: recent developments TS02 Paweł Owczarek Details and experim... more Thermoacoustic refrigeration systems: recent developments TS02 Paweł Owczarek Details and experimental results of a stand-alone container cooled by a solar driven multi-stage traveling wave thermoacoustic system TS04 Chris Lawn Optimization of the loop in a travelling-wave thermo-acoustic engine TS05 Maurice-Xavier Francois The VALTA project: full scale conversion of CHP engine flue gas heat into electricity 12:20 13:20 Lunch Grand café 13:20 14:40 Session 2a Erlenmeyer AE05 Douglas Wilcox Development of a compact thermoacoustic-Stirling electric generator AE02 Jeffrey Lin High-fidelity simulations of a standing-wave thermoacousticpiezoelectric engine AE04 Bakhtier Farouk Signal conditioning of carbon nanotube loudspeaker AE01 Ken Kaneuchi Evaluation of bi-directional turbines using the two-sensor method 14:40 14:50 Coffee The Gallery 14:50 16:10 Session 3a Erlenmeyer AE03 Johan Brussen Modeling and controlling the generator of a thermoacoustic Stirling engine AE06 Maurice-Xavier Francois Space thermoacoustic radio-isotopic power system: SpaceTRIPS TS15 Hiroaki Hyodo Dynamics of forced synchronization in thermoacoustic system 16:10 16:20 Coffee The Gallery 16:20 17:20 Session 4a Erlenmeyer TC01 Marialuisa Napolitano The role of stack non acoustic parameters on thermodynamic performance of standing wave devices TC02 Esmatullah Maiwand Sharify CFD study of oscillatory flow around parallel plates in a traveling-wave thermoacoustic engine

Research paper thumbnail of Towards the application of thermoacoustic cooling in office buildings : performance governing parameters and models for performance predictions

Solar assisted thermoacoustic cooling is with the recent advances in energy conversion efficiency... more Solar assisted thermoacoustic cooling is with the recent advances in energy conversion efficiency an interesting alternative to sorption based technologies. Although thermoacoustic cooling is characterized with a slightly reduced COP, is has the advantage to require little to no maintenance and has zero global warming potential. To successfully use the technology to cool office buildings an optimally designed machine and a careful building integration is required. To assess the integrated performance of building, thermoacoustic cooler and heat rejection system, the authors propose to use building and system performance simulation tools. However, there are no component models readily available to model a thermoacoustic cooler within those environments. In this contribution the authors aim to determine the needed modelling complexity level for a component model of a thermoacoustic cooler. As the energy conversion efficiencies are sensitive to geometrical and operational parameter of t...

Research paper thumbnail of Implementing a bidirectional impulse turbine into a thermoacoustic refrigerator

The Journal of the Acoustical Society of America, 2020

Research paper thumbnail of Review on the conversion of thermoacoustic power into electricity

The Journal of the Acoustical Society of America, 2018

Thermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently in... more Thermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently into electric power. This article provides a review of the four main methods to convert the (thermo)acoustic power into electricity. First, loudspeakers and linear alternators are discussed in a section on electromagnetic devices. This is followed by sections on piezoelectric transducers, magnetohydrodynamic generators, and bidirectional turbines. Each segment provides a literature review of the given technology for the field of thermoacoustics, focusing on possible configurations, operating characteristics, output performance, and analytical and numerical methods to study the devices. This information is used as an input to discuss the performance and feasibility of each method, and to identify challenges that should be overcome for a more successful implementation in thermoacoustic engines. The work is concluded by a comparison of the four technologies, concentrating on the possible area...

Research paper thumbnail of The VALTA project: Full scale conversion of CHP engine flue gas heat into electricity

Proceedings of the 3rd International Workshop on Thermoacoustics, 2015

Research paper thumbnail of Space thermoacoustic radio-isotopic power system: SpaceTRIPS

Proceedings of the 3rd International Workshop on Thermoacoustics, 2015

Research paper thumbnail of Novel 4-Stage Traveling Wave Thermoacoustic Power Generator

ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting: Volume 2, Fora, 2010

Utilizing low temperature differences from solar vacuum tube collectors or waste heat in the rang... more Utilizing low temperature differences from solar vacuum tube collectors or waste heat in the range 70–200 °C seems to be the most promising and commercial interesting field of applications for thermoacoustic systems. Recently a novel 4-stage “self matching” traveling wave engine is developed and tested. Beside the low acoustic loss and compactness, due to traveling wave feedback, all components per stage are identical which is beneficial from (mass) production point of view. Based on this concept a 100 kWT thermoacoustic power (TAP) generator is under construction. This project is carried out in the framework of phase two of the Dutch SBIR program. The 100 kWT TAP will be installed at a paper manufacturing plant in the Netherlands for converting part of the flue gas at 150°C from the paper drying process into electricity. Emphasis in this project is on production and cost aspects lowering the investment per kWe to a level competitive to ORC’s. After successful completion of this pil...

Research paper thumbnail of COSNET-a coherent optical subscriber network

Journal of Lightwave Technology, 1993

A complete coherent multi-channel system, designed for application in the local loop is presented... more A complete coherent multi-channel system, designed for application in the local loop is presented. The concept and the technical realization of a uni-and bi-directional system in a laboratory demonstrator are described. The realized network control, including frequency management of the bi-directional channels, and network security are discussed. Attention is paid to the evolution scenario from a narrow band to a complete broad-band system. All aspects are integrated in a demonstrator, which is capable of supporting a large number of narrow-band and broad-band distributive and communicative services. Several novel technical solutions (for frequency management, data induced polarization switching (DIPS), high-speed encryption and network signalling) are presented.