The apparatus of scan measurement was used to gather the temperature pattern at the combustor outlet,where the average working temperature of gas was about 1700Kand the maximum temperature was about 1 950K.Consequentl...The apparatus of scan measurement was used to gather the temperature pattern at the combustor outlet,where the average working temperature of gas was about 1700Kand the maximum temperature was about 1 950K.Consequently,the measurement part was cooled by water or air.Usually,for intermittent measurement devices,the interval of circle angel could be changed to get a high-density temperature distribution.A continuous measurement manner was adopted to get point in circle.The angle between two measurepoints was 1.286°.The annular combustor outlet was about 40to 50mm in height,where 5or 6measure points were usually arranged.In this device,10measure points were arranged in a range of 45.5mm.Four thermocouples were arranged in circle to obtain 2 800measure-points of the temperature field in a single experiment.Data were drawn from the whole datasheet at intervals.Each group of data whose number decreased in turn,included temperature points of 2 800,1 400,700,and 350,respectively.Several groups of temperature distributions with different densities were established.Subsequently,data processing was conducted to calculate the main combustor characteristics,including arithmetic or integral average temperature,OTDF(overall temperature distribution factor)and RTDF(radial temperature distribution factor).It is found that the data from different groups with different measuring densities result in significant difference on the combustor characteristics.The veracity of temperature characteristics increases with the growing measure-density.展开更多
Nanomeasuring machines developed at the Technische Universitat Ilmenau enable three-dimensional measurements and manufacturing processes with the lowest uncertainties.Due to the requirements for these processes,a high...Nanomeasuring machines developed at the Technische Universitat Ilmenau enable three-dimensional measurements and manufacturing processes with the lowest uncertainties.Due to the requirements for these processes,a highly reproducible and long-term stable tool changing system is needed.For this purpose,kinematically determined couplings are widely used.The state-of-the-art investigations on those are not sufficient for the highest demands on the reproducibility required for this application.A theoretical determination of the reproducibility based on analytical or numerical methods is possible,however not in the desired nanometer range.Due to this,a measurement setup for the determination of the reproducibility in five degrees of freedom with nanometer uncertainty was developed.First,potential measuring devices are systematically examined and measurement principles were developed out of this.A three-dimensional vector-based uncertainty analysis is performed to prove the feasibility of the measurement principle and provides a basis for further design.As a result,a transla-tory measurement uncertainty of 10 nm and a rotatory uncertainty of 11 nrad can be reached.Afterwards,the measurement setup is designed,focusing on the metrological frame and the lift-off device.The developed setup exceeds the uncertainties of the measurement setups presented in the state-of-the-art by an order of magnitude,allowing new in-depth investigations of the reproducibility of kinematic couplings.展开更多
文摘The apparatus of scan measurement was used to gather the temperature pattern at the combustor outlet,where the average working temperature of gas was about 1700Kand the maximum temperature was about 1 950K.Consequently,the measurement part was cooled by water or air.Usually,for intermittent measurement devices,the interval of circle angel could be changed to get a high-density temperature distribution.A continuous measurement manner was adopted to get point in circle.The angle between two measurepoints was 1.286°.The annular combustor outlet was about 40to 50mm in height,where 5or 6measure points were usually arranged.In this device,10measure points were arranged in a range of 45.5mm.Four thermocouples were arranged in circle to obtain 2 800measure-points of the temperature field in a single experiment.Data were drawn from the whole datasheet at intervals.Each group of data whose number decreased in turn,included temperature points of 2 800,1 400,700,and 350,respectively.Several groups of temperature distributions with different densities were established.Subsequently,data processing was conducted to calculate the main combustor characteristics,including arithmetic or integral average temperature,OTDF(overall temperature distribution factor)and RTDF(radial temperature distribution factor).It is found that the data from different groups with different measuring densities result in significant difference on the combustor characteristics.The veracity of temperature characteristics increases with the growing measure-density.
基金the support by the Deutsche Forschungsgemeinschaft(DFG)in the framework of Research Training Group"Tip-and laser-based 3D-Nanofabrication inextended macroscopic working areas"(GRK 2182)at the Technische Universiat Ilmenau,Germany.
文摘Nanomeasuring machines developed at the Technische Universitat Ilmenau enable three-dimensional measurements and manufacturing processes with the lowest uncertainties.Due to the requirements for these processes,a highly reproducible and long-term stable tool changing system is needed.For this purpose,kinematically determined couplings are widely used.The state-of-the-art investigations on those are not sufficient for the highest demands on the reproducibility required for this application.A theoretical determination of the reproducibility based on analytical or numerical methods is possible,however not in the desired nanometer range.Due to this,a measurement setup for the determination of the reproducibility in five degrees of freedom with nanometer uncertainty was developed.First,potential measuring devices are systematically examined and measurement principles were developed out of this.A three-dimensional vector-based uncertainty analysis is performed to prove the feasibility of the measurement principle and provides a basis for further design.As a result,a transla-tory measurement uncertainty of 10 nm and a rotatory uncertainty of 11 nrad can be reached.Afterwards,the measurement setup is designed,focusing on the metrological frame and the lift-off device.The developed setup exceeds the uncertainties of the measurement setups presented in the state-of-the-art by an order of magnitude,allowing new in-depth investigations of the reproducibility of kinematic couplings.
