A method for analyzing the thermal comfort of a vehicle occupant compartment

Abstract

The present invention discloses a method for analyzing the thermal comfort of a vehicle occupant compartment, which includes the following steps: building a CFD flow field analysis model of the occupant compartment; respectively building a basic thermal analysis model of the occupant compartment and a passenger physiological model and combining them to form a thermal analysis model of the occupant compartment; building a thermal analysis model in the preheating stage; building a transient CFD flow field analysis model of the occupant compartment; building a transient CFD flow field analysis model of the occupant compartment in the preheating stage; building a flow field model and a thermal analysis model of the occupant compartment in the driving stage, and coupling calculations to obtain the interior temperature and passenger comfort at different stages of the driving condition. By establishing a thermal comfort analysis model, the present invention can accurately obtain the cooling and heating thermal comfort performance of the occupant compartment during vehicle development, understand whether the cooling and heating loads of the air conditioning system meet the target design requirements, support the reasonable design of energy consumption, and at the same time avoid the situation of changing the component design in the later verification stage of the project, increasing the R & D investment and affecting the project cycle.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobiles and relates to a method for analyzing the thermal comfort of a vehicle occupant compartment. Background Art

[0002] Comfort is a key task in the development of vehicle air conditioning performance. With the booming development of the electric vehicle industry, the energy consumption of air conditioning systems has received increasing attention. How to balance both the comfort of using air conditioning and energy consumption has become an issue that engineers attach great importance to.

[0003] Currently, the industry generally estimates the interior temperature by combining the CFD flow field analysis results of the occupant compartment with the maximum and minimum heating and cooling loads of the air conditioning system. Using this method, there is often an overabundance of air conditioning performance and a large air conditioning energy consumption. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a method for analyzing the thermal comfort of a vehicle occupant compartment, which can accurately predict the air temperature in the occupant compartment and the comfort of passengers, and can help identify whether the air conditioning performance and energy consumption are excessive.

[0005] The object of the present invention is achieved by the following technical solutions:

[0006] A method for analyzing the thermal comfort of a vehicle occupant compartment includes the following steps:

[0007] S1. Build a CFD flow field analysis model of the occupant compartment;

[0008] S2. Build a basic thermal analysis model of the occupant compartment and a passenger physiological model respectively and combine them to form a thermal analysis model of the occupant compartment;

[0009] S3. Build a thermal analysis model for the preheating stage;

[0010] S4. Build a transient CFD flow field analysis model of the occupant compartment;

[0011] S5. Build a transient CFD flow field analysis model of the occupant compartment for the preheating stage;

[0012] S6. Build a flow field model and a thermal analysis model of the occupant compartment during the driving stage, and perform coupled calculations to obtain the interior temperature and passenger comfort at different stages of the driving condition.

[0013] Further, in step S1, the CFD software STARCCM+ is used to build a CFD flow field analysis model of the occupant compartment to obtain the air volume at each air outlet of the face-blowing or foot-blowing air ducts.

[0014] Further, step S2 includes:

[0015] S21. Export the cabin and passenger surface meshes from the CFD flow field analysis model of the passenger compartment respectively, and simplify the mesh elements;

[0016] S22. Import the simplified cabin surface mesh into the thermal analysis software TAItherm, set the material, thickness and surface condition properties of each part of the cabin, and build the basic cabin thermal analysis model;

[0017] S23. Import the simplified passenger surface mesh into the thermal analysis software TAItherm, set the personnel status and metabolic level, and physical conditions to build the passenger physiological model;

[0018] S24. Assemble the passenger physiological model onto the basic cabin thermal analysis model to form the cabin thermal analysis model, and set the thermal connection relationship and contact thermal resistance of the key components in the cabin in the cabin thermal analysis model;

[0019] Further, the step S3 includes: setting the thermal convection conditions of the key components in the cabin, the external convection environment and the preheating time according to the actual conditions of vehicle preheating, building the thermal analysis model in the preheating stage and setting the monitored quantities, and calculating the initial temperature of each wall surface in the cabin after preheating.

[0020] Further, the step S4 includes: building the transient CFD flow field analysis model of the passenger compartment using the computational fluid dynamics CFD software STARCCM+.

[0021] Further, the step S5 includes: taking the air volume and wall temperature of each air outlet in the calculation results of the flow field transient analysis model and the thermal analysis model in the preheating stage as boundary conditions and inputting them, and calculating the flow field in the cabin during the preheating process.

[0022] Further, the step S6 includes:

[0023] S61. Change the flow field model of the cabin during the preheating process, input the driving time of the vehicle as the calculation time of the model, and use this model as the flow field model for the thermal comfort of the cabin during the driving stage.

[0024] S62. Change the thermal analysis model in the preheating stage, re-enter the thermal convection conditions of the key components in the cabin, the model calculation time, the external convection environment conditions and other parameters, and use the thermal analysis model in the preheating stage as the initial condition to build the thermal comfort thermal analysis model during the driving stage, as Figure 2 shown;

[0025] S63. Use the CAE coupling software Cotherm to couple the flow field model for the thermal comfort of the cabin during the driving stage and the thermal comfort thermal analysis model during the driving stage, set the components to be coupled, the start and end times of coupling, the coupling interval, the solution time step of the flow field and thermal analysis models, and the monitored quantities;

[0026] S64. Coupling calculation, and after the calculation is completed, obtain the required parameter results, such as the temperature change in the occupant compartment and human comfort.

[0027] The present invention has the following beneficial effects:

[0028] By establishing a thermal comfort analysis model, the present invention can accurately obtain the cooling and heating thermal comfort performance of the occupant compartment during vehicle development, understand whether the cooling and heating loads of the air conditioning system meet the target design requirements, support the reasonable design of energy consumption, and at the same time avoid the situation of changing the component design during the later verification stage of the project, increasing the R & D investment and affecting the project cycle. Description of the Drawings

[0029] Figure 1 It is a flowchart of a method for analyzing the thermal comfort of a vehicle occupant compartment according to the present invention;

[0030] Figure 2 It is a thermal analysis model of the thermal comfort of the occupant compartment built according to the present invention. Detailed Embodiments

[0031] The technical solution of the present invention will be further described below in conjunction with the drawings and embodiments:

[0032] As Figure 1 shown, a method for analyzing the thermal comfort of a vehicle occupant compartment includes the following steps:

[0033] S1. Build a CFD flow field analysis model for the occupant compartment;

[0034] S2. Build a basic thermal analysis model for the occupant compartment and a passenger physiological model respectively and combine them to form a thermal analysis model for the occupant compartment;

[0035] S3. Build a thermal analysis model for the preheating stage;

[0036] S4. Build a transient CFD flow field analysis model for the occupant compartment;

[0037] S5. Build a transient CFD flow field analysis model for the occupant compartment during the preheating stage;

[0038] S6. Build a flow field model and a thermal analysis model for the occupant compartment during the driving stage, and perform coupling calculation to obtain the vehicle interior temperature and passenger comfort at different stages of the driving condition.

[0039] Further, in step S1, the CFD software STARCCM+ is used to build a CFD flow field analysis model for the occupant compartment to obtain the air volume at each air outlet of the face-blowing or foot-blowing air ducts.

[0040] Further, step S2 includes:

[0041] S21. Export the passenger compartment and passenger surface meshes from the CFD flow field analysis model of the passenger compartment respectively, and simplify the mesh elements;

[0042] S22. Import the simplified passenger compartment surface mesh into the thermal analysis software TAItherm, set the material, thickness and surface condition properties of each part of the passenger compartment, and build the basic thermal analysis model of the passenger compartment;

[0043] S23. Import the simplified passenger surface mesh into the thermal analysis software TAItherm, set the personnel status and metabolic level, and physical conditions to build the passenger physiological model;

[0044] S24. Assemble the passenger physiological model onto the basic thermal analysis model of the passenger compartment to form the thermal analysis model of the passenger compartment, and set the thermal connection relationship and contact thermal resistance of the key components in the passenger compartment in the thermal analysis model of the passenger compartment;

[0045] Further, the step S3 includes: setting the thermal convection conditions of the key components in the passenger compartment, the external convection environment and the preheating time according to the actual conditions of vehicle preheating, building the thermal analysis model in the preheating stage and setting the monitored quantities, and calculating the initial temperature of each wall surface of the passenger compartment after preheating.

[0046] Further, the step S4 includes: building a transient CFD flow field analysis model of the passenger compartment using the computational fluid dynamics CFD software STARCCM+.

[0047] Further, the step S5 includes: inputting the air volume of each air outlet and the wall surface temperature in the calculation results of the flow field transient analysis model and the thermal analysis model in the preheating stage as boundary conditions, and calculating the flow field in the passenger compartment during the preheating process.

[0048] Further, the step S6 includes:

[0049] S61. Modify the flow field model of the passenger compartment during the preheating process, input the driving time of the vehicle as the calculation time of the model, and use this model as the flow field model for thermal comfort in the driving stage of the passenger compartment.

[0050] S62. Modify the thermal analysis model in the preheating stage, re-enter the thermal convection conditions of the key components in the passenger compartment, the model calculation time, the external convection environment conditions and other parameters, and use the thermal analysis model in the preheating stage as the initial condition to build the thermal comfort thermal analysis model in the driving stage, as Figure 2 shown;

[0051] S63. Use the CAE coupling software Cotherm to couple the flow field model for thermal comfort in the driving stage of the passenger compartment and the thermal comfort thermal analysis model in the driving stage, set the components to be coupled, the start and end times of coupling, the coupling interval, the solution time step of the flow field and thermal analysis models, and the monitored quantities;

[0052] S64. Coupling calculation. After the calculation is completed, obtain the required parameter results, such as the temperature change in the passenger compartment and human comfort.

[0053] Embodiment

[0054] A method for analyzing the thermal comfort of a vehicle passenger compartment includes the following steps:

[0055] 1. Use the commercial computational fluid dynamics (CFD) software STARCCM+ to build a flow field model of the passenger compartment and obtain the air volume at each air outlet of the air ducts such as the face-blowing or foot-blowing ducts.

[0056] 2. Respectively export the passenger compartment and passenger surface meshes from the passenger compartment flow field model, and simplify the mesh elements to shorten the model calculation time.

[0057] 3. Import the simplified passenger compartment surface mesh into the commercial thermal analysis software TAItherm, set the properties such as the materials, thicknesses, and surface conditions of various parts of the passenger compartment (glass, door, A-pillar, instrument panel, seat, etc.), and build a basic thermal analysis model of the passenger compartment.

[0058] 4. Import the simplified passenger surface mesh into TAItherm, set the physical conditions such as the human state, metabolic level, and clothing to build a passenger physiological model.

[0059] 5. Assemble the passenger physiological model onto the basic thermal analysis model of the passenger compartment to form a thermal analysis model of the passenger compartment, and set the thermal connection relationship and contact thermal resistance of the key components in the passenger compartment in this model.

[0060] 6. Set the thermal convection conditions, external convection environment, and preheating time of the key components in the passenger compartment according to the actual conditions of vehicle preheating, build a preheating thermal analysis model and set the monitored quantities, and calculate the initial temperature of each wall surface of the passenger compartment after preheating.

[0061] 7. Use STARCCM+ to build a transient CFD flow field analysis model of the passenger compartment, and input the air volume at each air outlet and the wall temperature in the calculation results of the flow field model and the preheating model as boundary conditions to calculate the flow field in the passenger compartment during the preheating process.

[0062] 8. Modify the flow field model of the passenger compartment during the preheating process, input the driving time of the vehicle as the calculation time of the model, and use this model as the thermal comfort flow field model.

[0063] 9. Modify the preheating thermal analysis model, re-enter the parameters such as the thermal convection conditions of the key components in the passenger compartment, the model calculation time, and the external convection environment conditions, and use the preheating thermal analysis model as the initial condition to build a thermal comfort thermal analysis model, as Figure 2 shown;

[0064] 10. Use the CAE coupling software Cotherm to couple the thermal comfort flow field model and the thermal comfort thermal analysis model, and set the components to be coupled, the start and end times of coupling, the coupling interval, the solution time step of the flow field and the thermal analysis model, and the monitored quantities;

[0065] 11. Perform coupling calculations, and after the calculations are completed, obtain the required parameter results, such as the temperature change in the occupant compartment and human comfort.

Claims

1. A method for analyzing the thermal comfort of a vehicle occupant compartment, characterized in that, Including the following steps: S1. Build a CFD flow field analysis model for the crew cabin; S2. Build a basic thermal analysis model for the crew cabin and a passenger physiological model respectively and combine them to form a thermal analysis model for the crew cabin; The step S2 includes: S21. Export the surface meshes of the crew cabin and the passengers from the CFD flow field analysis model of the crew cabin respectively, and simplify the mesh elements; S22. Import the simplified surface mesh of the crew cabin into the thermal analysis software TAItherm, set the material, thickness and surface condition attributes of each part of the crew cabin, and build a basic thermal analysis model for the crew cabin; S23. Import the simplified surface mesh of the passengers into the thermal analysis software TAItherm, set the personnel status and metabolic level, and build a passenger physiological model according to the physical conditions; S24. Assemble the passenger physiological model onto the basic thermal analysis model of the crew cabin to form a thermal analysis model for the crew cabin, and set the thermal connection relationship and contact thermal resistance of the key components in the crew cabin in the thermal analysis model of the crew cabin; S3. Build a thermal analysis model for the preheating stage; S4. Build a transient CFD flow field analysis model for the crew cabin; S5. Build a transient CFD flow field analysis model for the crew cabin during the preheating stage; S6. Build a flow field model and a thermal analysis model for the crew cabin during the driving stage, and perform coupled calculations to obtain the vehicle interior temperature and passenger comfort at different stages of the driving conditions; The step S6 includes: S61. Modify the flow field model of the crew cabin during the preheating process, input the time of the vehicle driving process as the calculation time of the model, and use this model as the flow field model for the thermal comfort of the crew cabin during the driving stage; S62. Modify the thermal analysis model for the preheating stage, re-enter the thermal convection conditions of the key components in the crew cabin, the model calculation time, and the external convection environment condition parameters, and use the thermal analysis model for the preheating stage as the initial condition to build a thermal comfort thermal analysis model for the driving stage; S63. Use the CAE coupling software Cotherm to couple the flow field model for the thermal comfort of the crew cabin during the driving stage and the thermal comfort thermal analysis model for the driving stage, and set the components to be coupled, the start and end times of coupling, the coupling interval, the solution time step of the flow field and the thermal analysis model, and the monitored quantities; S64. Perform coupled calculations, and after the calculations are completed, obtain the required parameter results, such as the temperature change in the crew cabin and the human comfort level.

2. The method for analyzing the thermal comfort of a vehicle occupant compartment according to claim 1, characterized in that, In the step S1, the CFD software STARCCM+ is used to build a CFD flow field analysis model for the crew cabin to obtain the air volume at each air outlet of the face-blowing or foot-blowing air ducts.

3. The method for analyzing the thermal comfort of a vehicle occupant compartment according to claim 1, characterized in that, The step S3 includes: Set the thermal convection conditions of the key components in the crew cabin, the external convection environment and the preheating time according to the actual conditions of vehicle preheating, build a thermal analysis model for the preheating stage and set the monitored quantities, and calculate the initial temperature of each wall surface of the crew cabin after preheating.

4. The method for analyzing the thermal comfort of a vehicle occupant compartment according to claim 1, characterized in that, The step S4 includes: Use the CFD software STARCCM+ to build a transient CFD flow field analysis model for the crew cabin.

5. The method for analyzing the thermal comfort of a vehicle occupant compartment according to claim 1, characterized in that, The step S5 includes: Input the air volume at each air outlet and the wall surface temperature in the calculation results of the transient flow field analysis model and the thermal analysis model for the preheating stage as boundary conditions to calculate the flow field inside the crew cabin during the preheating process.

Images