Method of measuring friction stress on interference surface of oil film

A technology of frictional stress and interference surface, which is applied in fluid pressure measurement, measuring device, aerodynamic test and other directions using optical methods, can solve the problems of measurement result error and no consideration of viscosity coefficient change, etc., and achieve accurate results
CN104697705AInactive Publication Date: 2015-06-10INST OF HIGH SPEED AERODYNAMICS OF CHINA AERODYNAMICS RES & DEV CENT
4 Cites 11 Cited by

Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
INST OF HIGH SPEED AERODYNAMICS OF CHINA AERODYNAMICS RES & DEV CENT
Publication Date
2015-06-10
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a method of measuring friction stress on an interference surface of an oil film. The method comprises the following specific steps: step 1, obtaining a variable relationship of a viscosity coefficient [mu] of the oil film when time changes between a time t1 and a time t2, and measuring the thicknesses of the oil film at the time t1 and the time t2; step 2, setting an initial friction stress t0, calculating a thin oil film equation according to the variable relationship of the viscosity coefficient [mu] of the oil film when time changes, the thickness of the oil film at the time t1 and a numerical value, and adopting explicit time-marching to arrive at the time t2, so as to calculate the thickness of the oil film at the time t2; step 3, comparing the thickness of the oil film calculated at the time t2 with the thickness of the oil film measured at the time t2, correcting the friction stress t0 according to a comparison result, and carrying out explicit time-marching to the time t2 from the beginning of the time t1 again, wherein the t0 is the solved friction stress t after the circulation when the thickness of the oil film calculated is consistent to the thickness of the oil film measured. According to the method provided by the invention, the friction stress on the interference surface of the oil film can be obtained.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the technical field of test fluid mechanics, and discloses a method for measuring friction stress on an oil film interference surface. Background technique

[0002] Frictional resistance plays a very important role in the design of aircraft. For commercial aircraft, the frictional resistance accounts for almost 40% to 50% of the total resistance in the cruising state. It is estimated that reducing the resistance by 1% can increase about 10 passengers [1], both in terms of economic benefits and energy conservation and environmental protection. In terms of aspects, drag reduction is very important; for hypersonic powered aircraft, frictional resistance accounts for 30% of the total resistance, which is directly related to whether the aircraft can obtain positive thrust and whether the design scheme is successful; For re-entry gliding weapons, the size of frictional resistance directly affects its range, which is related to the s...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More