阅读说明：本技术 一种倾转多旋翼飞行器动力系统分布方案的设计方法 (Design method for power system distribution scheme of tilting multi-rotor aircraft ) 是由 严旭飞 娄斌 王晓波 陈令凯 谢也 谢安桓 张丹 于 2021-02-07 设计创作，主要内容包括：本发明公开了一种倾转多旋翼飞行器动力系统分布方案的设计方法,其包括倾转多旋翼飞行器基本参数设计方法,以及推重比、悬停拉力、单个旋翼失效和旋翼动力系统功耗分析方法。所述的倾转多旋翼飞行器基本参数设计方法是推重比、悬停拉力、单个旋翼失效和旋翼动力系统功耗分析方法的前提。通过本发明提出的研究方法,可以综合分析旋翼尺寸、桨叶片数、旋翼分布等对飞行器的推重比、悬停拉力以及单个旋翼失效后的修正影响,并同时考虑机翼展长限制,桨尖速度限制(旋翼噪声限制)以及动力系统功耗限制。该发明可以在倾转多旋翼飞行器的概念设计阶段快速确定合理的飞行器动力系统分布方案,从而显著加快飞行器概念设计的研究进程。(The invention discloses a design method of a power system distribution scheme of a tilting multi-rotor aircraft, which comprises a basic parameter design method of the tilting multi-rotor aircraft, and a thrust-weight ratio, hovering pull force, single rotor failure and power consumption analysis method of a rotor power system. The design method of the basic parameters of the tilting multi-rotor aircraft is the premise of a thrust-weight ratio, hovering tension, single rotor failure and a power consumption analysis method of a rotor power system. Through the research method provided by the invention, the influences of the size of the rotor, the number of blades, the distribution of the rotor and the like on the thrust-weight ratio and the hovering tension of an aircraft and the correction of a single rotor after failure can be comprehensively analyzed, and the span length limit, the tip speed limit (rotor noise limit) and the power consumption limit of a power system are considered at the same time. The method can quickly determine a reasonable aircraft power system distribution scheme in the conceptual design stage of the tilting multi-rotor aircraft, thereby remarkably accelerating the research process of the conceptual design of the aircraft.)

1. A design method for a power system distribution scheme of a tilting multi-rotor aircraft is characterized by comprising a design method for basic parameters of the tilting multi-rotor aircraft and a thrust-weight ratio, hovering pulling force, single rotor failure and power consumption analysis method for the rotor power system, wherein the basic parameters of the tilting multi-rotor aircraft comprise aircraft load, takeoff weight, wingspan, aspect ratio, cruising speed, thrust-weight ratio range, rotor root total pitch, blade negative torque and the like.

2. The method of designing a tiltrotor multi-rotor aircraft power-system distribution according to claim 1, wherein the multi-rotor aircraft includes at least 4 rotors.

3. The method for designing a power system distribution scheme of a tiltrotor multi-rotor aircraft according to claim 1, wherein the method for designing basic parameters of the tiltrotor multi-rotor aircraft comprises the following steps:

1) determining aircraft loads according to design requirements;

2) counting the takeoff weight ranges of various aircrafts according to the loads, and determining the takeoff weight;

3) counting the span ranges of various tilting multi-rotor aircrafts according to the load and the pneumatic configuration of the aircrafts, thereby determining the span and aspect ratio;

4) according to the load, the cruising speed range of various tilting multi-rotor aircrafts is counted, so that the cruising speed is determined;

5) according to the load, counting the thrust-weight ratio range of various tilting multi-rotor aircrafts;

6) and according to the load and the cruising speed, counting the total pitch of the propeller roots and the negative torque of the propeller blades of various tilting multi-rotor aircrafts, thereby determining a group of feasible total pitch of the propeller roots and negative torque of the propeller blades.

4. The method of claim 1 wherein the thrust-to-weight ratio, hover drag, single rotor failure and rotor power system power consumption analysis is performed by:

7) preliminarily determining a feasible rotor wing layout and a blade number set according to basic parameters of the tilting multi-rotor aircraft;

8) weight reduction ratio and power consumption analysis: respectively calculating and comparing the body thrust-weight ratio of each group of rotor wing layout and the blade number under the maximum allowable blade tip Mach number and the corresponding total power required by the rotor wing, and analyzing in a set to obtain a first group of feasible rotor wing layout and each rotor wing blade number range by taking low noise, low power consumption and large thrust-weight ratio as targets;

9) hovering pulling force and power consumption analysis: respectively calculating and comparing the total required power of the rotor power system under the condition of each group of rotor layout and the number of blades in the hovering state, and analyzing in a set to obtain a second group of feasible rotor layout and the number range of each rotor blade by taking low noise and low power consumption as targets;

10) preliminary analysis of single rotor failure: respectively calculating and comparing the corrected tension change of each group of rotor wing layout and the residual rotor wings under the blade number after a single rotor wing fails in a hovering state, and analyzing in a set to obtain a third group of feasible rotor wing layout and the blade number range of each rotor wing by taking low noise and low power consumption as targets;

11) and (4) taking intersection of the three groups of rotor layouts obtained in the steps 8) to 10) and the number range of each rotor blade to obtain a final power system distribution scheme of the tilting multi-rotor aircraft.

5. The method of designing a tiltrotor multi-rotor aircraft power system distribution scheme according to claim 4, wherein the maximum allowable tip mach number is 0.5Ma or 0.6 Ma.

6. The method of designing a tiltrotor aircraft power system distribution according to claim 4, wherein the rotor layout includes rotor number, rotor radius, and installation location.

7. The method for designing the power system distribution scheme of the tiltrotor multi-rotor aircraft according to claim 4, wherein when the target aircraft has only one wing, the situation that one of the wings fails is analyzed; when the target model has a front wing and a rear wing, the following conditions exist:

when the number of the rotors of the rear wing is less than that of the rotors of the front wing, the condition that one rotor on the rear wing fails is only needed to be analyzed.

When the number of the front wing rotors is less than that of the rear wing, the condition that one rotor on the front wing is invalid is only needed to be analyzed.

8. The method of designing a tiltrotor aircraft power system distribution scheme according to claim 7, wherein: when the number of the rotors of the front wing and the rear wing of the target airplane type is the same, the airplane body is more difficult to maintain flight after judging which rotor on which wing fails, and the condition that one rotor on the corresponding wing fails is analyzed.

Technical Field

The invention belongs to the field of aircraft design, and particularly relates to a design method of a power system distribution scheme of a tilting multi-rotor aircraft.

Background

Urban air traffic transportation and various special flight tasks (air sightseeing, logistics transportation, anti-terrorism and anti-riot, post-disaster rescue and the like) put higher requirements on the flight performance of the aircraft, including the capabilities of high-efficiency hovering performance, large voyage, high-speed flight entering and the like. The rotor assembly of the conventional rotor type aircraft has asymmetric left and right airflow when flying forwards, and the maximum flying speed of the conventional rotor type aircraft is limited by the airflow compressibility of the forward blades and airflow separation of the backward blades, so that the flying speed is difficult to further improve.

In order to overcome the problems, researchers at home and abroad make a great deal of exploration and attempt and provide a plurality of new configuration schemes. The tilting multi-rotor aircraft can give consideration to both low-speed hovering and high-speed forward flying performance, and is a novel structural scheme which is successful at present. In addition, due to the application of a distributed power (DEP) technology, the redundancy of a power system is improved, and the step-by-step tilting of the rotor wing assembly can be realized, so that the tilting multi-rotor aircraft can meet the aims of safety and high efficiency. However, due to the presence of DEP multi-rotor configurations, the distribution scheme of the rotor power system has been a difficult problem in the conceptual design phase of tiltrotor multi-rotor aircraft: if the number of the rotors is too small, the safe landing of the aircraft body after the failure of a single rotor cannot be ensured, or the flight task can be continuously completed; if the rotor number is too much, then because organism size's restriction, the oar dish area of whole rotor group can reduce by a wide margin, leads to aerodynamic efficiency to descend, increases the consumption on foot.

Disclosure of Invention

The invention aims to provide a design method of a power system distribution scheme of a tilting multi-rotor aircraft aiming at the defects of the prior art.

The purpose of the invention is realized by the following technical scheme: a design method for a power system distribution scheme of a tilting multi-rotor aircraft comprises a design method for basic parameters of the tilting multi-rotor aircraft and an analysis method for thrust-weight ratio, hovering pulling force, single rotor failure and power consumption of the rotor power system, wherein the basic parameters of the tilting multi-rotor aircraft comprise aircraft load, takeoff weight, wingspan, aspect ratio, cruising speed, thrust-weight ratio range, rotor root total pitch and blade negative torque.

Further, the multi-rotor aircraft comprises at least 4 rotors.

Further, the method for designing the basic parameters of the tilting multi-rotor aircraft comprises the following steps:

1) determining aircraft loads according to design requirements;

2) counting the takeoff weight ranges of various aircrafts according to the loads, and determining the takeoff weight;

3) counting the span ranges of various tilting multi-rotor aircrafts according to the load and the pneumatic configuration of the aircrafts, thereby determining the span and aspect ratio;

4) according to the load, the cruising speed range of various tilting multi-rotor aircrafts is counted, so that the cruising speed is determined;

5) according to the load, counting the thrust-weight ratio range of various tilting multi-rotor aircrafts;

6) and according to the load and the cruising speed, counting the total pitch of the propeller roots and the negative torque of the propeller blades of various tilting multi-rotor aircrafts, thereby determining a group of feasible total pitch of the propeller roots and negative torque of the propeller blades.

Further, the thrust-weight ratio, hovering pull force, single rotor failure and power consumption analysis method of the rotor power system is realized by the following steps:

7) preliminarily determining a feasible rotor wing layout and a blade number set according to basic parameters of the tilting multi-rotor aircraft; the rotor wing layout comprises the number of rotor wings, the radius of the rotor wings and the installation position;

8) weight reduction ratio and power consumption analysis: respectively calculating and comparing the body thrust-weight ratio of each group of rotor wing layout and the blade number under the maximum allowable blade tip Mach number and the corresponding total power required by the rotor wing, and analyzing in a set to obtain a first group of feasible rotor wing layout and each rotor wing blade number range by taking low noise, low power consumption and large thrust-weight ratio as targets;

9) hovering pulling force and power consumption analysis: respectively calculating and comparing the total required power of the rotor power system under the condition of each group of rotor layout and the number of blades in the hovering state, and analyzing in a set to obtain a second group of feasible rotor layout and the number range of each rotor blade by taking low noise and low power consumption as targets;

10) preliminary analysis of single rotor failure: respectively calculating and comparing the corrected tension change of each group of rotor wing layout and the residual rotor wings under the blade number after a single rotor wing fails in a hovering state, and analyzing in a set to obtain a third group of feasible rotor wing layout and the blade number range of each rotor wing by taking low noise and low power consumption as targets;

11) and (4) taking intersection of the three groups of rotor layouts obtained in the steps 8) to 10) and the number range of each rotor blade to obtain a final power system distribution scheme of the tilting multi-rotor aircraft.

Further, the maximum allowable tip mach number is 0.5Ma or 0.6 Ma.

Further, when the target machine type only has one wing, analyzing the condition that one rotor on the wing fails; when the target airplane type has a front wing and a rear wing, the following three conditions exist:

when the number of the rotors of the rear wing is less than that of the rotors of the front wing, only the failure condition of one rotor on the rear wing needs to be analyzed;

when the number of the front wing rotors is less than that of the rear wing, only the condition that one rotor on the front wing is invalid needs to be analyzed;

when the number of the rotors of the front wing and the rear wing is the same, the aircraft body is more difficult to maintain flight after a single rotor on which part of the wings fails according to the actual condition, and the failure condition of one rotor on the corresponding wing is analyzed.

The invention has the following beneficial effects: the invention comprehensively analyzes the influences of the size of the rotor, the number of blades, the distribution of the rotor and the like on the thrust-weight ratio and the hovering tension of the aircraft and the correction effect of the single rotor after failure, and simultaneously considers the limitation of the span length of the aircraft, the limitation of the speed of a blade tip (the limitation of the noise of the rotor) and the limitation of the power consumption of a power system. The invention can quickly determine a reasonable aircraft power system distribution scheme in the conceptual design stage of the tilting multi-rotor aircraft, thereby remarkably accelerating the research process of the conceptual design of the aircraft.

Detailed Description

The present invention will be described in detail below based on preferred embodiments, and objects and effects of the present invention will become more apparent, and the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention discloses a design method of a power system distribution scheme of a tilting multi-rotor aircraft, which comprises a design method of basic parameters of the tilting multi-rotor aircraft, and a thrust-weight ratio, hovering pull force, single rotor failure and power consumption analysis method of a rotor power system. The basic parameters of the tilting multi-rotor aircraft comprise aircraft load, takeoff weight, wingspan, aspect ratio, cruising speed, thrust-weight ratio range, rotor root total pitch and blade negative torque; the multi-rotor aircraft includes at least 4 rotors. The basic parameter design method of the tilting multi-rotor aircraft is a precondition of a thrust-weight ratio, hovering tension, single rotor failure and a power consumption analysis method of a rotor power system.

For convenience of understanding, it is assumed herein that all rotor parameters employed by the tiltrotor multi-rotor aircraft in this embodiment are consistent. The present embodiment includes the following steps:

1. the method for designing basic parameters of the tilting multi-rotor aircraft comprises the following sub-steps:

1.1, determining the load of the aircraft according to the mission use and the design requirement of the aircraft: taking passenger capacity as a design index, and taking the weight of 100kg per passenger as a design amount; the weight determination is carried out by the general standard of goods according to the goods as the design index.

1.2, takeoff weight of aircraft: and counting the takeoff weight ranges of various aircrafts according to the design load, so as to determine the takeoff weights of various aircrafts.

1.3, the wingspan and aspect ratio of the aircraft: according to the load and the pneumatic configuration of the aircraft, the wingspan ranges of various tilting multi-rotor aircraft with the power system close to the prototype are counted, and therefore the wingspan and aspect ratio are determined.

1.4, cruising speed of the aircraft: according to the load, the cruise speed range of various current tilting multi-rotor aircrafts is counted, so that the cruise speed is determined.

1.5, thrust-weight ratio of the aircraft: according to the design load, the thrust-weight ratio range of various tilting multi-rotor aircrafts is counted, so that the thrust-weight ratio is determined.

1.6, the total pitch of the rotor root of the aircraft and the negative torque of the blades: the rotor root total pitch and the blade negative torque are two most main parameters influencing the pulling force and the power of a rotor, and the total pitch and the blade negative torque of the roots of various conventional tilting multi-rotor aircrafts can be counted according to the load and the cruising speed, so that a group of feasible root total pitch and blade negative torque are determined and used as basic parameters of the rotor blades for subsequent thrust-weight ratio and power consumption analysis and single rotor failure preliminary analysis.

2. The method for analyzing the thrust-weight ratio, the hovering pulling force, the single rotor failure and the power consumption of the rotor power system comprises the following substeps:

and 2.1, preliminarily determining feasible combinations of m rotor layout schemes and the number n of blades according to the basic parameters obtained in the step 1. The rotor wing layout parameters specifically include the number of rotor wings, the radius (size) of the rotor wings, the specific installation position on the machine body and the like.

2.2, weight-push ratio and power consumption analysis: the body thrust-weight ratios of m rotor wing layouts and n blades at two types of maximum blade tip Mach numbers (such as low wave resistance 0.5Ma and medium and high wave resistance 0.6Ma) and the corresponding total power requirements of the rotor wings are analyzed and compared respectively. With the goals of low noise, low power consumption and large thrust-weight ratio as targets, a first set of feasible rotor layouts and the range of the number of rotor blades are obtained through analysis in the set and recorded as S1. The blade tip Mach number has a direct relation with the rotor noise, and the smaller the blade tip Mach number is, the smaller the rotor noise is.

2.3, analyzing hovering pulling force and power consumption: the tilting multi-rotor aircraft needs to enter a hovering state in the vertical take-off and landing, fixed-point detection and sightseeing processes, the rotor has a high induced speed in the hovering state, the required power is high, and other pneumatic components cannot generate aerodynamic force and aerodynamic moment (except for aerodynamic interference of rotor wake flow), so that the hovering state is a state needing to be considered firstly when the size and the distribution scheme of the rotor of the aircraft with the new configuration are researched. And respectively analyzing and comparing the total required power of the rotor power system under m rotor layouts and n blades when the body is suspended, and analyzing and obtaining a second group of feasible rotor layouts and the number range of each rotor blade in a set by taking low noise and low power consumption as targets, wherein the range is recorded as S2.

2.4, single rotor failure preliminary analysis: after a single rotor wing of the wing fails, the rotor wings at the symmetrical positions need to be directly closed, so that the balance in the rolling direction is ensured, and the residual rotor wings jointly improve the pulling force so as to maintain the balance of the pitching moment and the gravity; preliminarily analyzing the corrected tension change of the residual rotors after the single rotor fails in the hovering state of the aircraft with the new configuration: under m kinds of rotor layouts, n pieces of paddle of analysis contrast respectively, after single rotor became invalid, the correction pulling force of remaining rotor changes, with low noise and low-power consumption as the target, analysis obtained the feasible rotor layout of third group and each rotor paddle number scope in the set, mark as S3. When the target machine type only has one wing, analyzing the condition that one rotor on the wing fails; when the target airplane type has a front wing and a rear wing, the following three conditions exist: when the number of the rotors of the rear wing is less, the flight maintenance is more difficult after the single rotor on the rear wing fails, so that the condition that only one rotor on the rear wing fails needs to be analyzed; when the number of the front wing rotors is small, the maintenance of flight after the failure of a single rotor on the front wing is more difficult, so that the condition that only one rotor on the front wing is failed needs to be analyzed; when the number of the rotors of the front wing and the rear wing is the same, the aircraft body is more difficult to maintain flight according to the situation that in the actual situation, after a single rotor on one part of the wings fails, and the situation that one rotor on the part of the wings fails is analyzed.

And 2.5, taking intersection of the three groups of rotor layouts and the number ranges S1, S2 and S3 of the rotor blades to finally obtain a power system distribution scheme of the tilting multi-rotor aircraft, which can meet the requirements of maneuverability, low noise, low power consumption and high safety.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and although the invention has been described in detail with reference to the foregoing examples, it will be apparent to those skilled in the art that various changes in the form and details of the embodiments may be made and equivalents may be substituted for elements thereof. All modifications, equivalents and the like which come within the spirit and principle of the invention are intended to be included within the scope of the invention.