A laminar kinetic energy model based on the Klebanoff-mode dynamics to predict bypass transition

A theory is presented for calculating the fluctuations in a laminar boundary layer when the free stream is turbulent. The kinetic energy equation for these fluctuations is derived and a new mechanism is revealed for their production. A methodology is presented for solving the equation using standard boundary layer computer codes. Solutions of the equation show that the fluctuations grow at first almost linearly with distance and then more slowly as viscous dissipation becomes important. Comparisons of calculated growth rates and kinetic energy profiles with data show good agreement. In addition, a hypothesis is advanced for the effective forcing frequency and free-stream turbulence level that produce these fluctuations. Finally, a method to calculate the onset of transition is examined and the results compared to data.

Download Full-text

A novel energy model based predictive motion estimation algorithm

2014 22nd Iranian Conference on Electrical Engineering (ICEE) ◽

10.1109/iraniancee.2014.6999545 ◽

2014 ◽

Author(s):

Amir Ghahremani ◽

Amir Mousavinia

Keyword(s):

Motion Estimation ◽

Estimation Algorithm ◽

Energy Model ◽

Model Based ◽

Motion Estimation Algorithm

Download Full-text

Realistic energy model based energy balanced optimization for Low Rate WPAN network

IEEE Southeastcon 2009 ◽

10.1109/secon.2009.5174087 ◽

2009 ◽

Author(s):

Kunjie Xu ◽

Ivan Howitt

Keyword(s):

Energy Model ◽

Model Based ◽

Balanced Optimization ◽

Low Rate

Download Full-text

Development of a Building Energy Model Based on State-Space Analysis and Determining the Performance Characteristics

Lecture Notes in Mechanical Engineering - Recent Advances in Mechanical Engineering ◽

10.1007/978-981-15-8704-7_24 ◽

2020 ◽

pp. 199-204

Author(s):

V. S. K. V. Harish ◽

Arun Kumar

Keyword(s):

State Space ◽

Building Energy ◽

Energy Model ◽

Performance Characteristics ◽

Space Analysis ◽

State Space Analysis ◽

Model Based

Download Full-text

Logistics 4.0 Energy Modelling

Research Anthology on Cross-Industry Challenges of Industry 4.0 ◽

10.4018/978-1-7998-8548-1.ch023 ◽

2021 ◽

pp. 436-460

Author(s):

Megashnee Munsamy ◽

Arnesh Telukdarie ◽

Pavitra Dhamija

Keyword(s):

Industry 4.0 ◽

Energy Demand ◽

Business Processes ◽

Industrial Revolution ◽

Ghg Emissions ◽

Energy Model ◽

Logistics Network ◽

Model Based ◽

Research Propositions ◽

Energy Optimisation

Logistics activities are significant energy consumers and known contributors to GHG emissions, hence optimisation of logistics energy demand is of critical importance. The onset of the fourth Industrial revolution delivers significant technological opportunities for logistics optimisation with additional benefits in logistics energy optimisation. This research propositions a business process centric logistics model based on Industry 4.0. A Logistics 4.0 architecture is developed comprising Industry 4.0 technologies and associated enablers. The Industry 4.0 architecture components are validated by conducting a Systematic Literature Review on Industry 4.0 and logistics. Applying the validated Logistics 4.0 architecture to a cyber physical logistics energy model, based on the digitalisation of business processes, a comprehensive simulation is developed identified as the Logistic 4.0 Energy Model. The model simulates the technological impact of Industry 4.0 on a logistics network. The model generates energy and CO2 emission values for “as-is” and “to-be” Industry 4.0 scenarios.

Download Full-text

A Bypass Transition Model Based on the Intermittency Function

Flow Turbulence and Combustion ◽

10.1007/s10494-014-9533-9 ◽

2014 ◽

Vol 93 (1) ◽

pp. 37-61 ◽

Cited By ~ 24

Author(s):

Xuan Ge ◽

Sunil Arolla ◽

Paul Durbin

Keyword(s):

Transition Model ◽

Bypass Transition ◽

Model Based

Download Full-text

The Path to Predicting Bypass Transition

Volume 1: Turbomachinery ◽

10.1115/96-gt-199 ◽

1996 ◽

Cited By ~ 3

Author(s):

R. E. Mayle ◽

A. Schulz

Keyword(s):

Boundary Layer ◽

Kinetic Energy ◽

Energy Equation ◽

Free Stream ◽

Bypass Transition ◽

Turbulence Level ◽

Free Stream Turbulence ◽

Energy Profiles ◽

Computer Codes ◽

Good Agreement

A theory is presented for calculating the fluctuations in a laminar boundary layer when the free stream is turbulent. The kinetic energy equation for these fluctuations is derived and a new mechanism is revealed for their production. A methodology is presented for solving the equation using standard boundary layer computer codes. Solutions of the equation show that the fluctuations grow at first almost linearly with distance and then more slowly as viscous dissipation becomes important. Comparisons of calculated growth rates and kinetic energy profiles with data show good agreement. In addition, a hypothesis is advanced for the effective forcing frequency and free-stream turbulence level which produce these fluctuations. Finally, a method to calculate the onset of transition is examined and the results compared to data.

Download Full-text

Local-Correlation Based Zero-Equation Transition Model for Turbomachinery

Volume 1: Compressors, Fans, and Pumps; Turbines; Heat Transfer; Structures and Dynamics ◽

10.1115/gtindia2019-2615 ◽

2019 ◽

Cited By ~ 1

Author(s):

Jatinder Pal Singh Sandhu

Keyword(s):

Kinetic Energy ◽

Turbulent Kinetic Energy ◽

Gamma Transition ◽

Test Case ◽

Transition Model ◽

Bypass Transition ◽

Local Correlation ◽

New Model ◽

Transition Prediction ◽

Transition Mechanism

Abstract In this paper, we present a new local-correlation based zero-equation transition model. The new model, which is derived from the local-correlation based one-equation gamma transition model (Menter, F. R., Smirnov, P. E., Liu, T., and Avancha, R., A One-Equation Local Correlation-Based Transition Model, Flow, Turbulence and Combustion, vol. 95, 2015, pp. 583619.), does not require any additional equation to be solved, by defining a new variable, which captures the turbulent kinetic energy and intermittency collectively. The new model only adds three more source terms to the existing transport equation of turbulent kinetic energy. Hence the new model is straightforward to implement in already existing RANS solvers and reduces the computational memory requirement as compared to the other transition models. The transition prediction capability of the new model is tested and compared against the one-equation gamma transition model, especially for turbomachinery applications, where bypass transition is the primary transition mechanism, using a standard flat plate test case, and S809 airfoil. Preliminary results show that the new zero-equation transition model produces satisfactory results in terms of transition-location prediction.

Download Full-text