Simulation and Experimental Study of the Characteristic Parameters of an Aircraft Cabin Temperature Control Valve

Round 1

Reviewer 1 Report

The paper titled  ”Simulation and Experimental Study of the Characteristic Parameters of an Aircraft Cabin Temperature Control Valve" is reviewed and the authors must revise the paper before it is going to be accepted.

1. The authors must discuss the most relevant literature from the reputed publications in introduction section.

2. Compare the present results with the existing literature.

2. The discussion part in the result analysis should be expanded.

3. The conclusion must be revised with major findings and also incorporate the scope of this work in future.

4. References must be updated with the most recent articles last 5 years.

Author Response

Point 1: The authors must discuss the most relevant literature from the reputed publications in introduction section.

Response 1: The author adds discussion of relevent literature in introduction. We added the sentence to the introduction section as follows:

• In recent years, the research on aircraft cabin temperature control strategy mainly includes fuzzy control [4], expert-PID decoupling control [5], and neural network algorithm [6]. Yonggui Zheng et al. [7] used table-based LPID (Lookup PID) controllers to control the temperature and pressure of the aircraft bleed air simulation test. The dynamic test errors were within 10%, and the steady-state accuracies were within ±2%. Alexander Pollok [8] proposed a new aircraft cabin temperature control system based on PID control and LQG (Linear Quadratic Regulator) control, which can effectively reduce the temperature difference of air mixing chamber to reduce energy consumption of keeping the temperature difference as small as possible.
• Jennious et al. [10] simulated the air conditioning system of the Boeing 737-800 under two different operating conditions. They concluded that changes in the aircraft's environmental conditions have a significant impact on the steady-state outlet temperature and have a significant impact on the heat transfer efficiency in the primary and secondary heat exchangers. The method of temperature control by mixing hot-side gas and colde-side gas is unstable under variable environmental conditions. Sathiyaseelan A. and Arul Mozhi Selvan V. [11] found out the cabin inlet temperature control system would fluctuate more during the substantial change in aircraft flight altitude stage by using AMESim simulation, which means that the traditional method cannot effectively control the hot-side gas under variable conditions.

Point 2: Compare the present results with the existing literature.

Response 2: The author adds the comparison with existing literature in the conclusion part:

Compared with the current temperature control strategies based on the mixing hot-side and cold-side gases in the air mixing chamber introduced in the Introduction section of this paper, the control strategy proposed in this paper can be used under the condition that the engine is the source of hot-side gas without the hot-side and the cold-side air mixing directly. Therefore, the hot-side gas can be directly controlled, the control efficiency can be improved, and the energy consumption generated by the air mixing chamber temperature difference can be reduced.

Point 3: The discussion part in the result analysis should be expanded.

Response 3: The author adds the following discussion on the steady-state identification results of heat exchangers in the disscussion section:

According to the result of the temperature control valve system characteristic test experiment, the affecting factors of heat exchanger efficiency under different working conditions are obtained. In order to achieve the temperature adaptive control system, based on 25-point orthogonal experimental data, the second-order polynomial interpolation model of heat exchanger is identified by experiment. The experimental results show that the fitting accuracy of the heat exchanger model reaches 0.985. Based on this model, this paper takes the unit step hot-side outlet stable temperature as the heat exchanger model input and the hot-side outlet temperature as the output, to obtain the transfer function of the heat exchanger under different flow conditions.

Point 4: The conclusion must be revised with major findings and also incorporate the scope of this work in future.

Response 4:   The conclusion part has been revised according to the major findings of this paper, and the future work scope has been added. The conclusion is revised as follows:

In this paper, the heat exchanger is designed to achieve heat exchange between the hot gas and the cold gas of a temperature control system without mixing, effectively improving the cold gas and the hot gas of the original temperature control system. The disadvantage is the unstable flow from the back to the outlet. Through the CAD modeling of the temperature control value system, an Ansys simulation is designed to qualitatively analyze the influence of the temperature at the outlet of the hot path on the temperature control value system. Then a characteristics test experiment for the temperature control valve and heat exchanger is designed. The current is used to control the torque motor; a series of data are collected; the simulation conclusion is verified; and the possible reasons for the temperature control valve system’s effect on the change of the temperature at the outlet of the hot path are analyzed based on the two aspects of simulation and experiment. Based on the affecting factor, a four-segment identification experiment was designed to analyze the dynamic characteristics of the heat exchanger. According to the experimental data, the steady-state model of the heat exchanger is obtained by a 25-point orthogonal experiment. Taking the predicted hot-side flow rate of the heat exchanger under different flow conditions as input, the heat exchanger model is fitted and dynamically analyzed, which obtains the transfer function of heat exchanger under different working conditions.

In this paper, the mathematical model of the temperature control system is established for the temperature control system, and the dynamic simulation of the temperature control valve is carried out by Ansys, and the main factor of the temperature change of the hot-side outlet is the flow rate of the cold-side gas, the flow rate of the hot-side gas, heat exchanger efficiency and the NTU coefficients. Controlling the butterfly valve rotation can effectively control the cold-side of the gas flow to achieve the hot-side of the gas temperature control. The dynamic time constant of heat exchanger obtained in this paper, combined with the given phase margin and current phase angle, can be used to calculate the maximum lead angle to calculate the real-time PID parameters of the control system and realize the adaptive control of the temperature valve motor.

Compared with the current temperature control strategies based on the mixing hot-side and cold-side gases in the air mixing chamber introduced in the Introduction section of this paper, the control strategy proposed in this paper can be used under the condition that the engine is the source of hot-side gas without the hot-side and the cold-side air mixing directly. Therefore, the hot-side gas can be directly controlled, the control efficiency can be improved, and the energy consumption generated by the air mixing chamber temperature difference can be reduced.

The future work of this paper will be to fit the experimental dynamic time constant of the heat exchanger. According to the given phase margin, and the current angle of the system, the cutoff frequency, open-loop transfer function and maximum advance angle of the system can be calculated. The real-time PID parameters of the temperature control valve can be calculated to realize the adaptive control of the temperature control system under different working conditions.

Point 5: References must be updated with the most recent articles last 5 years.

Response 5: The references have all been updated for the last 5 years. The refences are as follows:

1. Mu, Y.; Liu, M.; Ma, Z. Research on the Measuring Characteristics of a New Design Butterfly Valve Flowmeter. Flow Measurement and Instrumentation, 2019, 70, 101651. [CrossRef]
2. Alexander, P.; Daniel, B.; Ines, K.; Dirk, Z. Rapid Development of an Aircraft Cabin Temperature Regulation Concept. In the Proceedings of the 12th International Modelica Conference, Prag, Germany, 2017. [CrossRef]
3. Liu, Y.; Wu, C.; Min, Z.; Zhang X. Control Logic Design Based on Modeling of Aircraft Cockpit Temperature Control System. In the Proceedings of the International Conference on Man-Machine-Environment System Engineering, Singapore, 2019. [CrossRef]
4. Sathiyaseelan, A.; Arul, M. S. V. Temperature Control of Combat Aircraft Environmental Control System by Time-delay in Loop with Control Input Normalization. In the Proceedings of the 2020 Fourth International Conference on Inventive Systems and Control (ICISC), Coimbatore, India, 8-10, January 2020. [CrossRef]
5. Ren, M.; Wang, J.; Li, R.; Dang, Y. Control law design for temperature control system of large-scale aircraft cabin. Acta Aeronauticaet Astronautica Sinca, 2017, 38, 721501. [CrossRef]
6. Zhang, T. H.; You, X. Y. The Use of Genetic Algorithm and Self-updating Artificial Neural Network for the inverse design of cabin environment. Indoor and Environment, 2017, 26, 347-354. [CrossRef]
7. Zheng, Y.; Liu, M.; Wu, H.; Wang, J. Temperature and Pressure Dynamic Control for the Aircraft Engine Bleed Air Simulation Test Using the LPID Controller. Aerospace, 2021, 8, 367. [CrossRef]
8. Pollok, A. Control Strategies for an Advanced Aircraft-cabin Temperature-system. In the Proceedings of the 2017 IEEE Conference on Control Technology and Applications (CCTA), Maui, HI, USA, 27-30 August 2017. [CrossRef]
9. Yang, Y.; Gao, Z. Power Optimization of the Environmental Control System for the Civil more Electric Aircraft. Energy, 2019, 172, 196-206. [CrossRef]
10. Jennious, I.; Ali, F.; Miguez, M. E.; Escobar, I. C. Simulation of an Aircraft Environmental Control System. Applied Thermal Engineering, 2020, 172, 114925. [CrossRef]
11. Sathiyaseelan, A.; Arul, M. S. V. Modeling and Simulation of a Fighter Aircraft Cabin Temperature Control System Using AMESim. SAE Technical Paper, 2020, 28, 497. [CrossRef]
12. Khan, K. A.; Butt, A. R.; Raza, N. Effects of Heat and Mass Transfer on Unsteady Boundary Layer Flow of a Chemical Reacting Casson Fluid. Results in Physics, 2018, 8, 610-620. [CrossRef]
13. Khan, K. A.; Butt, A. R.; Raza, N.; Maqbool, K. Unsteady Magneto-hydrodynamics Flow between two Orthogonal Moving Porous Plates. The European Physical Journal Plus, 2019, 134, 1. [CrossRef]
14. Fakheri, A.; Heat Exchanger Fundamentals: Analysis and Theory of Design; Springer, Cham: Berlin/Heidelberg, Germany, 2018; pp. 1315–1352. [CrossRef]

Reviewer 2 Report

It's a good work for the readers who intended to do work in that domain.

Comments for author File: Comments.pdf

Author Response

Point 1: Many terms are used in abbreviations. Please explain them. Better to add the nomen-clature.

Response 1: The author added nomenclature, which can be found in the attachment to pdf.

Point 2: The simulation software should be explained more so that the paper should be more beneficial for the reader.

Response 2: The author describes the simulation model built by Ansys and MATLAB simulation software.

• In the solution process, the initial condition parameters of each inlet fluid need to be set in Ansys simulation. In Ansys, this paper sets the butterfly valve pipeline flow rate by finite element analysis method. By using the principle and algorithm of gas heat exchange, the predicted flow rate and temperature of hot-side and cold-side gas at different valve angles can be obtained in the simulation program.
• Using MATLAB, the experimental data of the heat exchanger is processed, and the steady-state model of the heat exchanger is identified by using the algorithm to 25 orthogonal experimental data. By writing MATLAB program to obtain 25 sets of experimental results and fitting algorithm processing, the steady-state interpolation model of the heat exchanger is identified.

Point 3: Bibliography: There are still many papers in the allied fields that are not cited. In your bibliography ('introduction' section), quote the above- mentioned papers (i) Temperature and Pressure Dynamic Control for the Aircraft Engine Bleed Air Simulation Test Using the LPID Controller (ii) MODELING AND SIMULATION OF A FIGHTER AIRCRAFT CABIN TEMPERATURE CONTROL SYSTEM USING AMESIM (iii) Effects of heat and mass transfer on unsteady boundary layer flow of a chemical reacting Casson fluid, Results in physics 8, 610-620. (iv) Unsteady magneto-hydrodynamics flow between two orthogonal moving porous plates, The European Physical Journal Plus 134 (1)

Response 3: In the introduction section, the author updated to the following literature:

1. Mu, Y.; Liu, M.; Ma, Z. Research on the Measuring Characteristics of a New Design Butterfly Valve Flowmeter. Flow Measurement and Instrumentation, 2019, 70, 101651. [CrossRef]
2. Alexander, P.; Daniel, B.; Ines, K.; Dirk, Z. Rapid Development of an Aircraft Cabin Temperature Regulation Concept. In the Proceedings of the 12th International Modelica Conference, Prag, Germany, 2017. [CrossRef]
3. Liu, Y.; Wu, C.; Min, Z.; Zhang X. Control Logic Design Based on Modeling of Aircraft Cockpit Temperature Control System. In the Proceedings of the International Conference on Man-Machine-Environment System Engineering, Singapore, 2019. [CrossRef]
4. Sathiyaseelan, A.; Arul, M. S. V. Temperature Control of Combat Aircraft Environmental Control System by Time-delay in Loop with Control Input Normalization. In the Proceedings of the 2020 Fourth International Conference on Inventive Systems and Control (ICISC), Coimbatore, India, 8-10, January 2020. [CrossRef]
5. Ren, M.; Wang, J.; Li, R.; Dang, Y. Control law design for temperature control system of large-scale aircraft cabin. Acta Aeronauticaet Astronautica Sinca, 2017, 38, 721501. [CrossRef]
6. Zhang, T. H.; You, X. Y. The Use of Genetic Algorithm and Self-updating Artificial Neural Network for the inverse design of cabin environment. Indoor and Environment, 2017, 26, 347-354. [CrossRef]
7. Zheng, Y.; Liu, M.; Wu, H.; Wang, J. Temperature and Pressure Dynamic Control for the Aircraft Engine Bleed Air Simulation Test Using the LPID Controller. Aerospace, 2021, 8, 367. [CrossRef]
8. Pollok, A. Control Strategies for an Advanced Aircraft-cabin Temperature-system. In the Proceedings of the 2017 IEEE Conference on Control Technology and Applications (CCTA), Maui, HI, USA, 27-30 August 2017. [CrossRef]
9. Yang, Y.; Gao, Z. Power Optimization of the Environmental Control System for the Civil more Electric Aircraft. Energy, 2019, 172, 196-206. [CrossRef]
10. Jennious, I.; Ali, F.; Miguez, M. E.; Escobar, I. C. Simulation of an Aircraft Environmental Control System. Applied Thermal Engineering, 2020, 172, 114925. [CrossRef]
11. Sathiyaseelan, A.; Arul, M. S. V. Modeling and Simulation of a Fighter Aircraft Cabin Temperature Control System Using AMESim. SAE Technical Paper, 2020, 28, 497. [CrossRef]
12. Khan, K. A.; Butt, A. R.; Raza, N. Effects of Heat and Mass Transfer on Unsteady Boundary Layer Flow of a Chemical Reacting Casson Fluid. Results in Physics, 2018, 8, 610-620. [CrossRef]
13. Khan, K. A.; Butt, A. R.; Raza, N.; Maqbool, K. Unsteady Magneto-hydrodynamics Flow between two Orthogonal Moving Porous Plates. The European Physical Journal Plus, 2019, 134, 1. [CrossRef]
14. Fakheri, A.; Heat Exchanger Fundamentals: Analysis and Theory of Design; Springer, Cham: Berlin/Heidelberg, Germany, 2018; pp. 1315–1352. [CrossRef]

Point 4: The conclusion section should be more enriched.

Response 4: The conclusion part has been revised according to the major findings of this paper, and the future work scope has been added. The conclusion is revised as follows:

In this paper, the heat exchanger is designed to achieve heat exchange between the hot gas and the cold gas of a temperature control system without mixing, effectively improving the cold gas and the hot gas of the original temperature control system. The disadvantage is the unstable flow from the back to the outlet. Through the CAD modeling of the temperature control value system, an Ansys simulation is designed to qualitatively analyze the influence of the temperature at the outlet of the hot path on the temperature control value system. Then a characteristics test experiment for the temperature control valve and heat exchanger is designed. The current is used to control the torque motor; a series of data are collected; the simulation conclusion is verified; and the possible reasons for the temperature control valve system’s effect on the change of the temperature at the outlet of the hot path are analyzed based on the two aspects of simulation and experiment. Based on the affecting factor, a four-segment identification experiment was designed to analyze the dynamic characteristics of the heat exchanger. According to the experimental data, the steady-state model of the heat exchanger is obtained by a 25-point orthogonal experiment. Taking the predicted hot-side flow rate of the heat exchanger under different flow conditions as input, the heat exchanger model is fitted and dynamically analyzed, which obtains the transfer function of heat exchanger under different working conditions.

In this paper, the mathematical model of the temperature control system is established for the temperature control system, and the dynamic simulation of the temperature control valve is carried out by Ansys, and the main factor of the temperature change of the hot-side outlet is the flow rate of the cold-side gas, the flow rate of the hot-side gas, heat exchanger efficiency and the NTU coefficients. Controlling the butterfly valve rotation can effectively control the cold-side of the gas flow to achieve the hot-side of the gas temperature control. The dynamic time constant of heat exchanger obtained in this paper, combined with the given phase margin and current phase angle, can be used to calculate the maximum lead angle to calculate the real-time PID parameters of the control system and realize the adaptive control of the temperature valve motor.

Compared with the current temperature control strategies based on the mixing hot-side and cold-side gases in the air mixing chamber introduced in the Introduction section of this paper, the control strategy proposed in this paper can be used under the condition that the engine is the source of hot-side gas without the hot-side and the cold-side air mixing directly. Therefore, the hot-side gas can be directly controlled, the control efficiency can be improved, and the energy consumption generated by the air mixing chamber temperature difference can be reduced.

The future work of this paper will be to fit the experimental dynamic time constant of the heat exchanger. According to the given phase margin, and the current angle of the system, the cutoff frequency, open-loop transfer function and maximum advance angle of the system can be calculated. The real-time PID parameters of the temperature control valve can be calculated to realize the adaptive control of the temperature control system under different working conditions.

Point 5: English grammar throughout the manuscript should be checked.

Response 5: The author readjusts the manuscript and correct some grammar errors.

Reviewer 3 Report

Comments:

1. Try to Improve the introduction part

2. Improve the quality of the graphs with high resolution

3. Try to rectify typo and grammatical mistakes

4. What is the main novelty of the present investigation.

5.  Add Nomenclature with SI units

 

 

Author Response

Point 1: Try to Improve the introduction part.

Response 1: The author revised the introduction section, revised the cited literature, and added the following sentences:

• According to the research results, the characteristics of the heat exchanger are analyzed, and the dynamic time constant suitable for the heat exchanger is obtained, which proves the feasibility of the adaptive aircraft cabin temperature control system.
• Therefore, the key point of controlling aircraft cabin temperature by mixing cold-side and hot-side gas is controlling the hot-side gas flow.
• In recent years, the research on aircraft cabin temperature control strategy mainly includes fuzzy control [4], expert-PID decoupling control [5], and neural network algorithm [6]. Yonggui Zheng et al. [7] used table-based LPID (Lookup PID) controllers to control the temperature and pressure of the aircraft bleed air simulation test. The dynamic test errors were within 10%, and the steady-state accuracies were within ±2%. Alexander Pollok [8] proposed a new aircraft cabin temperature control system based on PID control and LQG (Linear Quadratic Regulator) control, which can effectively reduce the temperature difference of air mixing chamber to reduce energy consumption of keeping the temperature difference as small as possible.
• Jennious et al. [10] simulated the air conditioning system of the Boeing 737-800 under two different operating conditions. They concluded that changes in the aircraft's environmental conditions have a significant impact on the steady-state outlet temperature and have a significant impact on the heat transfer efficiency in the primary and secondary heat exchangers. The method of temperature control by mixing hot-side gas and colde-side gas is unstable under variable environmental conditions. Sathiyaseelan A. and Arul Mozhi Selvan V. [11] found out the cabin inlet temperature control system would fluctuate more during the substantial change in aircraft flight altitude stage by using AMESim simulation, which means that the traditional method cannot effectively control the hot-side gas under variable conditions.
• Therefore, this paper proposed a heat exchanger model that does not directly mix the cold-side and hot-side gas to achieve adaptive temperature control of aircraft cabins. Compared with the traditional method of mixing cold-side and hot-side gas, the method proposed in this paper can directly control the hot-side gas provided by the engine to improve the control effect and reduce the energy consumption of the heat exchanger. Based on the fluid heat transfer efficiency theory proposed by Kashif Ali Khan, Asma Rashid Butt, et al. [12,13], this paper used Ansys to simulate and verify the temperature control valve system.

Point 2: Improve the quality of the graphs with high resolution.

Response 2: The author redraws the graph to improve resolution, which can be found in the attachment to pdf.

Point 3: Try to rectify typo and grammatical mistakes.

Response 3: The author readjusts the manuscript and correct some grammar and typo errors.

Point 4: What is the main novelty of the present investigation.

Response 4: Compared with the traditional aircraft cabin temperature control strategy, the main novelty of this paper is to propose a strategy method that does not directly mix cold-side and hot-side gases, so that the hot-side gases can be directly controlled. Ansys is built for simulation verification, and the transfer function of the heat exchanger under different working conditions is obtained by fitting algorithm. In order to make readers understand the main work of this paper more clearly, the author adds the following sentences in the introduction:

Therefore, this paper proposed a heat exchanger model that does not directly mix the cold-side and hot-side gas to achieve adaptive temperature control of aircraft cabins. Compared with the traditional method of mixing cold-side and hot-side gas, the method proposed in this paper can directly control the hot-side gas provided by the engine to improve the control effect and reduce the energy consumption of the heat exchanger.

Point 5: Add Nomenclature with SI units.

Response 5: The author unifies SI units, and adds the nomenclature, which can be found in the pdf attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Authors addressed all the comments. The revised paper may be accpeted.

Author Response

Thanks very much for your kind work and consideration on publication of our paper. On behalf of my co-authors, we would like to express our great appreciation to you.

Thank you and best regards.