An energy management method for blended wing body civil aircraft

Abstract

The present invention provides an energy management method for a blended wing body civil aircraft. First, the flight of the blended wing body civil aircraft is divided into multiple stages, and the power and energy consumption requirements within the entire flight profile are evaluated. Then, the power decomposition method is adopted to model and analyze the power models of the main power components of the blended wing body civil aircraft. Finally, an energy consumption optimization model is constructed, and an energy consumption optimization coefficient index is set up to dynamically adjust the power output ratio of each main power component. The present invention can adjust the load power in real time under the condition of meeting the flight mission requirements, and the energy management strategy proposed by the present invention has a more efficient performance and less fuel consumption compared with a single energy management strategy.

Description

Technical Field

[0001] The present invention relates to the field of aircraft energy management, and particularly to an energy management method for a blended wing body civil aircraft. Background Art

[0002] The blended wing body civil aircraft is an important direction for future aviation development. Studying the energy management of the blended wing body civil aircraft has the following important significances:

[0003] 1. The research on energy management can help reduce fuel consumption and improve the energy utilization efficiency of aircraft. This is of great significance for reducing operating costs, reducing dependence on limited energy resources, and reducing carbon emissions.

[0004] 2. The impact of the aviation industry on the environment has attracted increasing attention. One of the purposes of studying the energy management of the blended wing body civil aircraft is to reduce pollution to the atmospheric environment. By improving combustion efficiency, using renewable energy, and exploring energy recovery technologies, the adverse impact of aircraft on the environment can be reduced.

[0005] 3. The research on energy management can help improve the flight performance of the blended wing body civil aircraft. Optimizing the power system, improving energy supply and distribution strategies, and adopting advanced energy-saving technologies can improve the propulsion efficiency, acceleration performance, and range of aircraft, providing a better flight experience and service.

[0006] 4. The research on energy management needs to combine advanced technologies and innovative methods to promote the cross-development of the aviation engineering and energy fields. By researching and applying new power systems, energy recovery and reuse technologies, intelligent control systems, etc., the technology of the blended wing body civil aircraft can be continuously advanced, and new ideas and solutions can be provided for the development of the future aviation field.

[0007] Therefore, studying the energy management of the blended wing body civil aircraft can achieve energy conservation and emission reduction, environmental protection, improvement of flight performance, and promotion of technological innovation and sustainable development of the aviation field. This is of great significance for the sustainability of the aviation industry and the development of future air transportation. At present, the domestic research on the energy management of the blended wing body civil aircraft is still in its infancy, and the adopted energy management strategies are relatively single, without fully considering the changes in design requirements brought about by the change of the flight phase of the blended wing body civil aircraft. Summary of the Invention

[0008] In order to solve the problems existing in the prior art, the present invention provides an energy management method for wing-body fusion civil aircraft. The energy management method aims to realize multi-mode-based energy management according to the different flight phases of the wing-body fusion civil aircraft. The energy management method is generally divided into three steps. First, the present invention divides the flight of the wing-body fusion civil aircraft into multiple phases and evaluates the power and energy consumption requirements within the entire flight profile. Then, the present invention adopts the power decomposition method to model and analyze the power model of each major power component of the wing-body fusion civil aircraft. Finally, the present invention constructs an energy consumption optimization model and establishes an energy consumption optimization coefficient index to dynamically adjust the power output ratio of each major power component.

[0009] The technical solution of the present invention is:

[0010] An energy management method for a wing-body blended civil aircraft includes the following steps:

[0011] Step 1: Construct energy consumption demand indicators for different flight phases of the wing-body fusion civil aircraft. The flight phases include takeoff, climb, cruise, descent, and hovering. The energy consumption demand indicator of the wing-body fusion civil aircraft during the entire flight mission is obtained as follows:

[0012] E total =E to +E climb +E cruise +E des +E loiter

[0013] Among them E to is the energy consumption during takeoff, E climb is the energy consumption of the climbing section, E cruise is the energy consumption during the cruise phase, E des is the energy consumption in the descending section, E loiter is the energy consumption during the hovering phase;

[0014] Step 2: Determine the energy consumption of the wing-body blended civil aircraft during the entire flight mission:

[0015]

[0016] Where T total is the flight time; P i is the power of the ith power component of the wing-body integrated civil aircraft, P i =f(k i ), k i is the optimization coefficient of the i-th power component;

[0017] Step 3: Build an energy consumption optimization model

[0018]

[0019] By solving the energy consumption optimization model, the optimization coefficients of each power component that minimize the energy consumption can be obtained.

[0020] Furthermore, in step 1, the energy consumption in each stage is obtained through the following process:

[0021] The power model in the take-off stage is:

[0022]

[0023] In the formula, P to is the required power in the take-off stage; ρ to is the air density in the take-off stage; V to is the flight speed in the take-off stage; S is the wing area; W to (t) is the weight of the aircraft in the take-off stage; g is the acceleration due to gravity; μ is the rolling friction coefficient; C D_to (t) and C L_to (t) are the three-dimensional drag coefficient and lift coefficient in the take-off stage respectively;

[0024] Assume that the take-off time of the blended wing-body civil aircraft is T to , then the energy consumption of the aircraft in the take-off stage is:

[0025]

[0026] The power models in the climb, cruise, descent, and loiter stages are:

[0027]

[0028] In the formula, the subscript i = cl, cr, la, lo indicates the flight stage where the variable is located, cl is the climb stage, cr is the cruise stage, la is the descent stage, and lo is the loiter stage; P i (t), i = cl, cr, la, lo refers to the required power in the climb, cruise, descent, and loiter stages; ρ i , i = cl, cr, la, lo is the air density in the climb, cruise, descent, and loiter stages; V i , i = cl, cr, la, lo is the flight speed in the climb, cruise, descent, and loiter stages; W i , i = cl, cr, la, lo is the weight of the aircraft in the climb, cruise, descent, and loiter stages; V vi , i = cl, cr, la, lo is the vertical speed of the aircraft in the climb, cruise, descent, and loiter stages; C D0 is the drag coefficient; K is the power correction parameter;

[0029] Assume that the climb time of the blended wing-body civil aircraft is T climb, the time taken for the cruise phase is T cruise , the time taken for the descent phase is T des , the time taken for the loiter phase is T loiter , then the energy consumption of the aircraft during the climb, cruise, descent, and loiter phases is:

[0030]

[0031] Furthermore, in step 2, the energy consumption of the blended wing-body civil aircraft during the entire flight mission is:

[0032]

[0033] where P m is the power of the electric motor, P b is the power of the battery, P TE is the power of the engine, P k is the power of the non-propulsion system airframe.

[0034] Furthermore, in step 2, the power models are:

[0035] Construct the power model of the electric motor as

[0036]

[0037] In the formula, P motor is the selected power of the electric motor; p o is the power density of the electric motor; k m is the optimization coefficient of the electric motor power model;

[0038] Construct the power model of the battery as:

[0039]

[0040] In the formula, E b is the energy storage of the battery; e b is the energy density of the battery; C max and C min are the maximum and minimum available charge amounts of the battery respectively; k b is the optimization coefficient of the battery power model;

[0041] Construct the power model of the engine as:

[0042]

[0043] In the formula, P g is the selected power of the engine; η ge is the efficiency of the generator; p TE is the work mass ratio of the engine; k TE is the optimization coefficient of the engine power model;

[0044] The power model of the non-powered system airframe is constructed as follows:

[0045]

[0046] where V cruise_max is the maximum cruise speed; k k is the optimization coefficient of the non-powered system airframe power model; d1, d2, e1, e2, and e3 are the fitting coefficients of the airframe power model.

[0047] Furthermore, in step 2, the non-powered system airframe power model adopts

[0048]

[0049] Furthermore, in step 3, the energy consumption optimization model is

[0050]

[0051] Furthermore, in step 3, the performance constraints adopt four performance constraint conditions: takeoff distance, climb rate, maximum cruise speed, and landing distance.

[0052] In addition, the present invention also proposes corresponding computer programs, readable storage media, and systems:

[0053] A computer system includes: one or more processors, and a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the above method.

[0054] A computer-readable storage medium stores computer-executable instructions, and the instructions are used to implement the above method when executed.

[0055] A computer program includes computer-executable instructions, and the instructions are used to implement the above method when executed.

[0056] Advantageous Effects

[0057] An energy management method for a blended-wing-body civil aircraft provided by the present invention can adjust the load power in real time under the condition of meeting the flight mission requirements. In addition, this technology can effectively regulate the bus power, so that the load power on the bus can be satisfied in a timely manner without providing additional energy. Compared with a single energy management strategy, the energy management strategy proposed by the present invention has more efficient performance and less fuel consumption.

[0058] The following is a further explanation of the bus power: The concept of bus power belongs to the field of communication. Different from the traditional power concept, it does not refer to the physical energy consumption, but refers to the ratio of the total amount of useful information transmitted per unit time to the total amount of data transmitted per unit time. The method proposed in the present invention is a dynamic energy management strategy. Compared with the traditional single fixed energy management strategy, the method proposed in the present invention can make the total amount of useful information transmitted per unit time (reflected by the energy consumption instruction [k m ,k b ,k TE ,k k ) a dynamically changing process. Therefore, the effective regulation of the bus power here refers to the effective regulation of the total amount of useful information (i.e., the energy consumption instruction [k m ,k b ,k TE ,k k ).

[0059] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0061] Figure 1 is a flowchart of the energy management strategy designed by the present invention.

[0062] Figure 2 is a simulation diagram of solving the energy consumption optimization model in the embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0063] The present invention designs a multi-mode based energy management method according to different flight phases of a blended wing body civil aircraft. First, energy consumption analysis and estimation are carried out for different flight phases within the entire flight profile, and then the total aircraft energy consumption of the blended wing body civil aircraft during the entire flight mission is obtained; then, the power decomposition method is used to model and analyze the power models of each main power component of the blended wing body civil aircraft; finally, an energy consumption optimization model is constructed, and the energy consumption optimization coefficient index is obtained to dynamically adjust the power output ratio of each main power component.

[0064] The specific steps are as follows:

[0065] Step 1: Construct the energy consumption demand index for different flight phases of the blended wing body civil aircraft.

[0066] For a blended wing body civil aircraft, a complete flight mission consists of six stages: takeoff, climb, cruise, descent, loiter, and landing. Since the power energy consumption requirement during the landing stage is relatively small and has little impact on the accuracy of the overall energy consumption model, therefore, the present invention will mainly conduct energy consumption analysis and estimation for the following five flight stages: takeoff, climb, cruise, descent, and loiter.

[0067] (1) For the takeoff stage, the power model for the takeoff stage is constructed as:

[0068]

[0069] In the formula, P to is the required power during the takeoff stage; ρ to is the air density during the takeoff stage; V to is the flight speed during the takeoff stage; S is the wing area; W to (t) is the aircraft weight during the takeoff stage; g is the acceleration due to gravity; μ is the rolling friction coefficient; C D_to (t) and C L_to (t) are the three-dimensional drag coefficient and lift coefficient during the takeoff stage respectively. It should be noted that the first term on the right side of the takeoff stage power model equation is the power required to resist aerodynamic drag; the second term is the power required to generate acceleration; the third term is the power required to overcome frictional drag.

[0070] Assume that the time taken for the takeoff section of the blended wing body civil aircraft is T to , then the energy consumption of the aircraft during the takeoff stage is:

[0071]

[0072] (2) For the climb, cruise, descent, and loiter stages, the power model for the climb, cruise, descent, and loiter stages is constructed as:

[0073]

[0074] In the formula, the subscript i = cl, cr, la, lo indicates the flight stage where the variable is located, cl is the climb stage, cr is the cruise stage, la is the descent stage, and lo is the loiter stage; P i (t), i = cl, cr, la, lo refers to the required power during the climb, cruise, descent, and loiter stages; ρ i , i = cl, cr, la, lo is the air density during the climb, cruise, descent, and loiter stages; V i , i = cl, cr, la, lo is the flight speed during the climb, cruise, descent, and loiter stages; W i , i = cl, cr, la, lo is the aircraft weight during the climb, cruise, descent, and loiter stages; V vi, where \(i = cl, cr, la, lo\) represents the vertical speed of the aircraft during the climb, cruise, descent, and loiter phases. \(C\) D0 is the drag coefficient; \(K\) is the power correction parameter, also known as the power sensitivity coefficient, and its value can be obtained through simulation experiments.

[0075] Assume that the time taken for the climb phase of a blended wing-body civil aircraft is \(T\) climb , the time taken for the cruise phase is \(T\) cruise , the time taken for the descent phase is \(T\) des , and the time taken for the loiter phase is \(T\) loiter . Then the energy consumption of the aircraft during the climb, cruise, descent, and loiter phases is:

[0076]

[0077] Therefore, the total aircraft energy consumption requirement index during the entire flight mission for the blended wing-body civil aircraft is:

[0078] \(E\) total \(=\) \(E\) to +\(E\) climb +\(E\) cruise +\(E\) des +\(E\) loiter (5)

[0079] Step 2: Use the power decomposition method to model and analyze the power models of the main power components of the blended wing-body civil aircraft.

[0080] (1) The power model of the electric motor is constructed as

[0081]

[0082] where \(P\) motor is the selected power of the electric motor; \(p\) o is the power density of the electric motor; \(k\) m is the optimization coefficient of the electric motor power model.

[0083] (2) Since the power of the battery depends not only on its maximum rated output power but also on the energy it needs to store, the power model of the battery is constructed as:

[0084]

[0085] where \(E\) b is the energy storage of the battery; \(e\) b is the energy density of the battery; \(C\) max and \(C\) min are the maximum and minimum available charge amounts of the battery respectively; \(k\) b is the optimization coefficient of the battery power model.

[0086] (3) The fuel power generation system consists of an engine and a generator. The power of the engine is determined by its selected power and the work mass ratio, and the power model of the generator is the same as that of the motor. Therefore, the engine power model is as follows:

[0087]

[0088] In the formula, P g is the selected power of the engine; η ge is the efficiency of the generator; p TE is the work mass ratio of the engine; k TE is the optimization coefficient of the engine power model.

[0089] (4) For a blended wing body civil aircraft, the power of the airframe without the engine system is called the non-power system airframe mass. The non-power system airframe power model is constructed as follows:

[0090]

[0091] In the formula, V cruise_max is the maximum cruise speed; k k is the optimization coefficient of the non-power system airframe power model; d1, d2, e1, e2, e3 are the fitting coefficients of the airframe power model. In this embodiment

[0092]

[0093] Assume the flight time is T total , then the energy consumption generated by the main power components of the blended wing body civil aircraft during the entire flight mission is:

[0094]

[0095] Step 3: Construct an energy consumption optimization model, and obtain the energy consumption optimization coefficient index to dynamically adjust the power output ratio of each main power component.

[0096] The energy consumption optimization model of the blended wing body civil aircraft constructed by the present invention is as follows:

[0097]

[0098] In the formula, p(x,u)≤0 refers to the performance constraint conditions of the blended wing body civil aircraft during the flight mission. In this embodiment, 4 performance constraint conditions are selected, namely: takeoff distance, climb rate, maximum cruise speed, landing distance.

[0099] Among them, the specific expression of the takeoff distance constraint condition is:

[0100] 0≤h init ≤h max (12)

[0101] The specific expression of the climb rate constraint condition is as follows:

[0102]

[0103] The specific expression of the maximum cruise speed constraint condition is as follows:

[0104] 0 ≤ V cruise ≤ V cruise,max (14)

[0105] The specific expression of the landing distance constraint condition is as follows:

[0106] 0 ≤ h end ≤ h end,max (15)

[0107] It should be noted that the maximum upper limit values of the 4 performance constraint conditions should be determined according to the actual flight performance of the aircraft.

[0108] The optimization objective function in this energy consumption optimization model is E total + E total2 , and it should be noted that E total + E total2 is not a fixed value because the calculation formula of E total + E total2 contains parameters [k m , k b , k TE , k k that need to be adjusted. As for the following constraint conditions, they are not reflected in the objective function but in the real-time flight process of the aircraft. This optimization process is a real-time optimization process. When we adjust the values of [k m , k b , k TE , k k , in essence, we are controlling the output ratios of the various energy mechanisms (motor, battery, engine, non-power mechanism) of the aircraft. Obviously, the values of [k m , k b , k TE , k k we calculate should at least ensure that the basic flight mission is feasible, that is, the following constraint conditions need to be satisfied.

[0109] Solving this energy consumption optimization model can obtain the optimized coefficient values [k m , k b , k TE , k k of each power model that minimize the energy consumption.. The solution method can utilize existing computing tools (such as the nonlinear optimization solution function fminsearch provided by Matlab), because this is simply an optimization solution problem, and we used this function during the simulation. Attached Figure 2 is what we obtained during the previous simulation for [k m , k b , k TE , k k 's changing process.

[0110] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.

Claims

1. An energy management method for a blended wing body civil aircraft, characterized in that: Including the following steps: Step 1: Construct the energy consumption demand indicators for different flight phases of the blended wing body civil aircraft. The flight phases include takeoff, climb, cruise, descent, and loitering. The whole-aircraft energy consumption demand indicator during the entire flight mission of the blended wing body civil aircraft is obtained as follows: E total = E to + E climb + E cruise + E des + E loiter Among which, E to is the energy consumption during the takeoff phase, E climb is the energy consumption during the climb phase, E cruise is the energy consumption during the cruise phase, E des is the energy consumption during the descent phase, E loiter is the energy consumption during the loiter phase; Step 2: Determine the energy consumption of the blended wing body civil aircraft during the entire flight mission as: where T total is the flight time; P i is the power of the i-th power component of the blended wing body civil aircraft, P i = f(k i ), k i is the optimization coefficient of the i-th power component; Step 3: Construct an energy consumption optimization model By solving the energy consumption optimization model, the optimization coefficients of each power component that minimize the energy consumption can be obtained.

2. The energy management method for a blended wing body civil aircraft according to claim 1, wherein: In Step 1, the energy consumption in each phase is obtained through the following process: The power model for the takeoff phase is: Wherein, P to is the required power during the takeoff phase; ρ to is the air density during the takeoff phase; V to is the flight speed during the takeoff phase; S is the wing area; W to (t) is the weight of the aircraft during the takeoff phase; g is the acceleration due to gravity; μ is the rolling friction coefficient; C D_to (t) and C L_to (t) are the three-dimensional drag coefficient and the lift coefficient during the takeoff phase, respectively; Let the takeoff time of a blended wing-body civil aircraft be T to , then the energy consumption of the aircraft during the takeoff phase is as follows: The power models for the climb, cruise, descent, and loitering phases are: In the formula, the subscript i = cl, cr, la, lo represents the flight phase where the variable is located. cl is the climb phase, cr is the cruise phase, la is the descent phase, and lo is the loiter phase; P i (t), i = cl, cr, la, lo refers to the required power in the climb, cruise, descent, and loiter phases; ρ i , i = cl, cr, la, lo is the air density in the climb, cruise, descent, and loiter phases; V i , i = cl, cr, la, lo is the flight speed in the climb, cruise, descent, and loiter phases; W i , i = cl, cr, la, lo is the aircraft weight in the climb, cruise, descent, and loiter phases; V vi , i = cl, cr, la, lo is the vertical speed of the aircraft in the climb, cruise, descent, and loiter phases; C D0 is the drag coefficient; K is the power correction parameter; Let the time taken for the climb phase of the blended wing-body civil aircraft be \(T\) climb and the time taken for the cruise phase be \(T\) cruise and the time taken for the descent phase be \(T\) des and the time taken for the loiter phase be \(T\) loiter Then the energy consumption of the aircraft during the climb, cruise, descent and loiter phases is as follows:

3. The energy management method for a blended wing body civil aircraft according to claim 1, characterized in that: In Step 2, the energy consumption of the blended wing body civil aircraft during the entire flight mission is: Among which, P m is the motor power, P b is the battery power, P TE is the engine power, P k is the power of the non-power system body.

4. The energy management method for a blended wing body civil aircraft according to claim 3, characterized in that: In Step 2, Construct the power model of the electric motor as Where, P motor is the selected power of the motor; p o is the power density of the motor; k m is the optimization coefficient of the motor power model; Construct the power model of the battery as: where, E b is the energy storage of the battery; e b is the energy density of the battery; C max and C min are the maximum and minimum available charge amounts of the battery respectively; k b is the battery power model optimization coefficient; Construct the power model of the engine as: Where, P g is the selected power of the engine; η ge is the efficiency of the generator; p TE is the working fluid ratio of the engine; k TE is the optimization coefficient of the engine power model; Construct the power model of the non-powered system airframe as: Where, V cruise_max is the maximum cruising speed; k k is the optimization coefficient of the body power model of the non-power system; d1, d2, e1, e2, and e3 are the fitting coefficients of the body power model.

5. The energy management method for a blended wing body civil aircraft according to claim 4, characterized in that: In Step 2, the power model of the non-powered system airframe adopts 6. The energy management method for a blended wing body civil aircraft according to claim 4, wherein: In Step 3, the energy consumption optimization model is 7. The energy management method for a blended wing body civil aircraft according to claim 1, characterized in that: In Step 3, the performance constraints adopt four performance constraint conditions: takeoff distance, climb rate, maximum cruise speed, and landing distance.

8. A computer system, comprising: One or more processors, a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method according to claims 1 to 7.

9. A computer-readable storage medium storing computer-executable instructions, which are used to implement the method according to claims 1 to 7 when executed.

10. A computer program comprising computer-executable instructions, which are used to implement the method according to claims 1 to 7 when executed.

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