One-dimensional Model of a Closed-loop Underwater Propulsion System

2015 ◽  
Author(s):  
Jun Lu
Keyword(s):  
Closed Loop ◽  
Propulsion System ◽  
Dimensional Model ◽  
One Dimensional ◽  
Underwater Propulsion

Research on quasi-one-dimensional modeling and performance analysis of RBCC propulsion system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dong Zhang ◽  
Feng Cheng ◽  
Shuo Tang ◽  
Chun-lin Gong ◽  
Bin Xu
Keyword(s):  
Energy Conservation ◽  
Flight Control ◽  
Transonic Flow ◽  
Propulsion System ◽  
Mixing Efficiency ◽  
Dimensional Model ◽  
Shock Train ◽  
Flow Area ◽  
One Dimensional ◽  
Dimensional Flow

Abstract Quasi-one-dimensional model is the most effective way to realize the rapid iterative design of the overall scheme and control system of RBCC aircraft and has become a research hotspot. In the current research, the quasi-one-dimensional model of RBCC propulsion system is simplified. The model does not include physical characteristics such as wall heat transfer, boundary layer change, specific heat ratio change and transonic flow singularity, which makes the accuracy of the model low and cannot adapt to flight control in large airspace. A RBCC model with high accuracy and adaptability to wide-speed fly is established in this paper. Firstly, based on the laws of kinetic energy conservation and energy conservation, the thrust model of ejection mode is established. Secondly, the quasi-one-dimensional flow control equation is deduced, and the physical mechanism models of core flow area, transonic flow, pre-combustion shock train, heat release law and mixing efficiency are established. On this basis, the quasi-one-dimensional flow model of RBCC dual-mode ramjet is established. Thirdly, based on the law of momentum conservation, the mathematical model of rocket mode is deduced, and the thrust model of rocket mode is established. Finally, the accuracy of the quasi-one-dimensional model is verified by CFD numerical simulation and direct-connect experiment. Taking a typical RBCC launch vehicle as an example, the wide-speed performance of the RBCC propulsion system is calculated and analyzed.

One-Dimensional Simulation and Experimental Investigation of the Shell-Integrated Condenser of the Underwater Closed-Loop Thermal Propulsion System

2016 ◽  
Vol 851 ◽  
pp. 369-376
Author(s):  
Yong Jun Han ◽  
Jun Lu ◽  
Cheng Shi Yang ◽  
Chao Bai ◽  
Zhao Yuan Guo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Optimization Design ◽  
Closed Loop ◽  
Propulsion System ◽  
Cross Sectional ◽  
One Dimensional ◽  
Unmanned Underwater Vehicles ◽  
Simulation And Optimization ◽  
Calculation Results ◽  
Dimensional Simulation

In order to understand heat transfer of the shell condenser in the closed-loop thermal propulsion system of the unmanned underwater Vehicles, the one-dimensional thermal model based on the hull-integrated condenser with helix channels is developed. After this, experimental research is conducted. Through the experiment data and theoretical calculation results compared, the accuracy of the heat transfer mathematical model is verified, and the correlation formulas about heat transfer are developed. In addition, the impacts of three factors on the performance of the shell condenser are investigated, including cross-sectional area of the cooling channel, flow rate and temperature of inlet steam. The research results indicate that the model and the correlation formulas about heat transfer is reliability and accuracy, which can provide a theoretical basis for simulation and optimization design of the shell condenser.

One-dimensional model of valveless pumping in a closed loop and a numerical solution

2006 ◽  
Vol 18 (1) ◽  
pp. 017106 ◽  
Author(s):  
Christos G. Manopoulos ◽  
Demetri S. Mathioulakis ◽  
Sokrates G. Tsangaris
Keyword(s):  
Numerical Solution ◽  
Closed Loop ◽  
Dimensional Model ◽  
One Dimensional ◽  
Valveless Pumping

Research on quasi-one-dimensional modeling and performance analysis of RBCC propulsion system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dong Zhang ◽  
Feng Cheng ◽  
Shuo Tang ◽  
Chun-lin Gong ◽  
Bin Xu
Keyword(s):  
Energy Conservation ◽  
Flight Control ◽  
Transonic Flow ◽  
Propulsion System ◽  
Mixing Efficiency ◽  
Dimensional Model ◽  
Shock Train ◽  
Flow Area ◽  
One Dimensional ◽  
Dimensional Flow

Abstract Quasi-one-dimensional model is the most effective way to realize the rapid iterative design of the overall scheme and control system of RBCC aircraft and has become a research hotspot. In the current research, the quasi-one-dimensional model of RBCC propulsion system is simplified. The model does not include physical characteristics such as wall heat transfer, boundary layer change, specific heat ratio change and transonic flow singularity, which makes the accuracy of the model low and cannot adapt to flight control in large airspace. A RBCC model with high accuracy and adaptability to wide-speed fly is established in this paper. Firstly, based on the laws of kinetic energy conservation and energy conservation, the thrust model of ejection mode is established. Secondly, the quasi-one-dimensional flow control equation is deduced, and the physical mechanism models of core flow area, transonic flow, pre-combustion shock train, heat release law and mixing efficiency are established. On this basis, the quasi-one-dimensional flow model of RBCC dual-mode ramjet is established. Thirdly, based on the law of momentum conservation, the mathematical model of rocket mode is deduced, and the thrust model of rocket mode is established. Finally, the accuracy of the quasi-one-dimensional model is verified by CFD numerical simulation and direct-connect experiment. Taking a typical RBCC launch vehicle as an example, the wide-speed performance of the RBCC propulsion system is calculated and analyzed.

Modelling Techniques in Applied Glaciology: Numerical Modelling of Avalanches

1983 ◽  
Vol 4 ◽  
pp. 297-297
Author(s):  
G. Brugnot
Keyword(s):  
Finite Difference Method ◽  
Transverse Velocity ◽  
Longitudinal Velocity ◽  
Momentum Conservation ◽  
Dimensional Model ◽  
One Dimensional ◽  
Modelling Techniques ◽  
Reference Grid ◽  
The One ◽  
Near Future

We consider the paper by Brugnot and Pochat (1981), which describes a one-dimensional model applied to a snow avalanche. The main advance made here is the introduction of the second dimension in the runout zone. Indeed, in the channelled course, we still use the one-dimensional model, but, when the avalanche spreads before stopping, we apply a (x, y) grid on the ground and six equations have to be solved: (1) for the avalanche body, one equation for continuity and two equations for momentum conservation, and (2) at the front, one equation for continuity and two equations for momentum conservation. We suppose the front to be a mobile jump, with longitudinal velocity varying more rapidly than transverse velocity.We solve these equations by a finite difference method. This involves many topological problems, due to the actual position of the front, which is defined by its intersection with the reference grid (SI, YJ). In the near future our two directions of research will be testing the code on actual avalanches and improving it by trying to make it cheaper without impairing its accuracy.

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