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Papers by Patricia Davies
The Journal of the Acoustical Society of America, 2008
The impact of aircraft noise on sleep disturbance is not accurately assessed by cumulative noise ... more The impact of aircraft noise on sleep disturbance is not accurately assessed by cumulative noise metrics that are often used to predict community impact, such as Ldn, because sleep disturbance is highly dependent on the noise level of individual events. Most existing sleep disturbance models are dose-response relationships that relate the noise level of individual events, as measured by SEL(A) or LAmax to the percent awakened, and independence of responses to individual events is assumed. There are a few models that also incorporate additional parameters such as time of night and noise sensitivity, and some that predict the impact of noise on sleep structure. In order to determine whether a model should be used as a general aircraft noise sleep disturbance prediction tool, its performance in a variety of situations must be evaluated. Data was collected from a number of sleep disturbance studies and comparisons were made between responses and model predictions of awakenings and sleep...
Volume 1: Fluid Applications and Systems; Fluid Measurement and Instrumentation, 2020
The bladeless fan is a new concept of fan that does not have visible impellers. It features low n... more The bladeless fan is a new concept of fan that does not have visible impellers. It features low noise level, uniform airflow, and improved safety. It has been widely applied in household appliances. Since the customers are particularly sensitive to the noise generated by the fan, the aeroacoustics performance of the fan needs to be accurately characterized in the design stage. In this study, computational fluid dynamic (CFD) and computational aeroacoustics (CAA) are applied to investigate the aeroacoustics performance and identify the major noise source of the bladeless fan. A prototype of the bladeless fan, including a wind channel, a base cavity, a rotor and a stator inside the base, is set in a computational domain of 4m × 2m × 2m and the airflow through the fan is simulated. The hybrid mesh is generated, the unstructured mesh in the near field, and the structured at the far field. To compute the flow field, steady RANS simulation (standard k–ε turbulence model) and Large Eddy si...
Acknowledgements We would like to thank and acknowledge the following people: o Paul Riehle and... more Acknowledgements We would like to thank and acknowledge the following people: o Paul Riehle and Randall Furnas of Roush Industries for their assistance in testing 2 Acoustical testing of diesel engines often requires a combination of fired and motored tests. Motored testing is a time-consuming and often expensive task. Reducing the needed amount of motored testing might: Reduce financial costs. Increase availability of testing resources (e.g., the semi-anechoic chamber and technical support). Motivations 3 Method demonstrates how a physical modification to an engine can be simulated by changing 'virtual sources' to simulate far-field noise.
Noise produced by components in a diesel affect the quality of the engine noise. One component so... more Noise produced by components in a diesel affect the quality of the engine noise. One component source related to consumer complaints is gear rattle. Gear rattle is caused by gear tooth impacts resulting from fluctuations in differential torsional acceleration of the driving gears. Previous work in this area has focused on rating the overall sound quality of diesel engines without specifically focusing on models for predicting the perception of gear rattle. Here, a method to generate sounds having different levels of gear rattle is described. First, diesel engine noise recordings were analyzed to determine the engine speed time histories; they were then used to guide gear impact timing and to generate gear noise components. The gear noise transfer paths were then tuned to improve the quality of the gear noise predictions. The gear noise simulation tool is presently being used to generate sounds for subjective tests designed to quantify the detectability, perception of growth, and ann...
International Journal of Solids and Structures, 2013
Journal of The Acoustical Society of America, 1993
The Journal of the Acoustical Society of America, 2008
The impact of aircraft noise on sleep disturbance is not accurately assessed by cumulative noise ... more The impact of aircraft noise on sleep disturbance is not accurately assessed by cumulative noise metrics that are often used to predict community impact, such as Ldn, because sleep disturbance is highly dependent on the noise level of individual events. Most existing sleep disturbance models are dose-response relationships that relate the noise level of individual events, as measured by SEL(A) or LAmax to the percent awakened, and independence of responses to individual events is assumed. There are a few models that also incorporate additional parameters such as time of night and noise sensitivity, and some that predict the impact of noise on sleep structure. In order to determine whether a model should be used as a general aircraft noise sleep disturbance prediction tool, its performance in a variety of situations must be evaluated. Data was collected from a number of sleep disturbance studies and comparisons were made between responses and model predictions of awakenings and sleep...
Volume 1: Fluid Applications and Systems; Fluid Measurement and Instrumentation, 2020
The bladeless fan is a new concept of fan that does not have visible impellers. It features low n... more The bladeless fan is a new concept of fan that does not have visible impellers. It features low noise level, uniform airflow, and improved safety. It has been widely applied in household appliances. Since the customers are particularly sensitive to the noise generated by the fan, the aeroacoustics performance of the fan needs to be accurately characterized in the design stage. In this study, computational fluid dynamic (CFD) and computational aeroacoustics (CAA) are applied to investigate the aeroacoustics performance and identify the major noise source of the bladeless fan. A prototype of the bladeless fan, including a wind channel, a base cavity, a rotor and a stator inside the base, is set in a computational domain of 4m × 2m × 2m and the airflow through the fan is simulated. The hybrid mesh is generated, the unstructured mesh in the near field, and the structured at the far field. To compute the flow field, steady RANS simulation (standard k–ε turbulence model) and Large Eddy si...
Acknowledgements We would like to thank and acknowledge the following people: o Paul Riehle and... more Acknowledgements We would like to thank and acknowledge the following people: o Paul Riehle and Randall Furnas of Roush Industries for their assistance in testing 2 Acoustical testing of diesel engines often requires a combination of fired and motored tests. Motored testing is a time-consuming and often expensive task. Reducing the needed amount of motored testing might: Reduce financial costs. Increase availability of testing resources (e.g., the semi-anechoic chamber and technical support). Motivations 3 Method demonstrates how a physical modification to an engine can be simulated by changing 'virtual sources' to simulate far-field noise.
Noise produced by components in a diesel affect the quality of the engine noise. One component so... more Noise produced by components in a diesel affect the quality of the engine noise. One component source related to consumer complaints is gear rattle. Gear rattle is caused by gear tooth impacts resulting from fluctuations in differential torsional acceleration of the driving gears. Previous work in this area has focused on rating the overall sound quality of diesel engines without specifically focusing on models for predicting the perception of gear rattle. Here, a method to generate sounds having different levels of gear rattle is described. First, diesel engine noise recordings were analyzed to determine the engine speed time histories; they were then used to guide gear impact timing and to generate gear noise components. The gear noise transfer paths were then tuned to improve the quality of the gear noise predictions. The gear noise simulation tool is presently being used to generate sounds for subjective tests designed to quantify the detectability, perception of growth, and ann...
International Journal of Solids and Structures, 2013
Journal of The Acoustical Society of America, 1993