WO2016125695A1 - 粗面の摩擦抵抗予測方法および表面性能評価装置 - Google Patents
粗面の摩擦抵抗予測方法および表面性能評価装置 Download PDFInfo
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- 235000019592 roughness Nutrition 0.000 claims description 171
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- 230000003746 surface roughness Effects 0.000 claims description 12
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N19/00—Investigating materials by mechanical methods
- G01N19/02—Measuring coefficient of friction between materials
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
- G01B11/06—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material
- G01B11/0608—Height gauges
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/30—Measuring arrangements characterised by the use of optical techniques for measuring roughness or irregularity of surfaces
- G01B11/303—Measuring arrangements characterised by the use of optical techniques for measuring roughness or irregularity of surfaces using photoelectric detection means
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- G—PHYSICS
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
- G01N13/02—Investigating surface tension of liquids
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/347—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
- G01N13/02—Investigating surface tension of liquids
- G01N2013/0216—Investigating surface tension of liquids by measuring skin friction or shear force
Definitions
- the present invention relates to a method for predicting an increase in frictional resistance of a rough surface in contact with a fluid, which is simple, without individual differences, and in which an evaluation result can be obtained quickly, and a frictional resistance increase evaluation apparatus using the prediction method.
- the present inventors have intensively studied a method and an apparatus capable of predicting an increase in frictional resistance of rough surfaces having different wavelengths for fluids having different flow velocities. As a result, the inventors have found that the following configuration can predict an increase in frictional resistance due to rough surfaces having different wavelengths, and have completed the present invention.
- the total exposed roughness projected area A per unit area exposed from the thickness of the viscous bottom layer (hereinafter referred to as “exposed roughness projected area A”) is evaluated.
- a frictional resistance prediction method for a rough surface wherein the frictional resistance increase rate FIR (%) is calculated by the following formula (1) or the frictional resistance increase ⁇ is calculated by the following formula (2).
- the coefficient C is a constant depending on the exposure roughness projected area A, and a friction resistance test is performed on a plurality of rough surfaces having different roughnesses by changing the flow velocity V in advance. %) are those obtained by measuring the.
- Note frictional resistance increase rate FIR (%) is the difference tau r-tau 0 frictional resistance tau 0 frictional resistance tau r and smooth the rough surface divided by tau 0 Percentage.
- the coefficient C r is a constant that depends on the fluid density ⁇ , the exposed roughness projected area A, and the flow velocity V, and the friction resistance test is performed by changing the flow velocity V for a plurality of rough surfaces having different roughnesses in advance.
- the frictional resistance increase ⁇ was measured and obtained from the relationship of equation (2).
- the frictional resistance increase ⁇ is a difference ⁇ r ⁇ 0 between the frictional resistance ⁇ r of the rough surface and the frictional resistance ⁇ 0 of the smooth surface.
- ⁇ s is the thickness of the viscous bottom layer, and is obtained by a frictional resistance test of the smooth surface.
- the frictional velocity u * is calculated from the frictional resistance ⁇ 0 of the smooth surface according to the equation (5).
- FIR % Or a value that increases the correlation coefficient between ⁇ and the exposure roughness projection area A is selected.
- Ra arithmetic mean roughness
- ⁇ roughness wavelength
- RSm roughness curve element average length
- R roughness height
- formula The method for predicting the frictional resistance of the rough surface according to [1], wherein the value of the projected projection area A of the exposure roughness calculated using 6) is used.
- the thickness ⁇ s of the viscous bottom layer used to calculate the exposure roughness projected area A is determined by the frictional resistance test of the smooth surface, and from the frictional resistance ⁇ 0 of the smooth surface by the above equation (3).
- the friction velocity u * is calculated, and the equation (1) among the values of ⁇ s calculated using the dimensionless distance y + (2 ⁇ y + ⁇ 8) and the kinematic viscosity coefficient ⁇ of the target fluid according to the equation (4).
- a value that increases the correlation coefficient between FIR (%) or ⁇ and the exposure roughness projection area A is selected.
- [6] An apparatus for evaluating surface performance by the prediction method according to any one of [1] to [5], A measuring section for measuring the roughness height R and the average length RSm of the roughness curve elements; Surface roughness characterized by comprising an exposure roughness projected area A and a calculation means for calculating the frictional resistance increase rate FIR (%) by the above equation (1) or the frictional resistance increase ⁇ by the above equation (2). Evaluation device.
- the measurement unit reads the moving distance with a rotary encoder or linear encoder, and the displacement with a laser displacement meter using a two-dimensional beam, and measures the roughness height R of the three-dimensional shape and the average length RSm of the roughness curve element.
- the surface performance evaluation apparatus according to [6].
- the present invention it is possible to directly calculate the increase in frictional resistance due to roughness in fluids with different flow velocities by a very simple method of simply evaluating the roughness. By using this method, it is possible to determine the surface treatment grade and surface treatment method in contact with the fluid at the target flow velocity.
- FIG. 3 is a schematic diagram showing changes in ⁇ s due to changes in flow velocity on rough surfaces having different roughness wavelengths.
- FIG. 4 is a schematic diagram for calculating the exposed projected area a from the viscous bottom layer ⁇ s using Rc.
- FIG. 5 shows the relationship between Rc and roughness parameters Rz, Ra, Rq, RZJIS.
- FIG. 6 shows a relationship diagram of Ra and roughness parameters Rz, Rc, Rq, RZJIS.
- FIG. 9 shows a schematic diagram of surface roughness measurement using a two-dimensional beam.
- the present invention evaluates the total exposed roughness projection area A per unit area exposed from the thickness of the viscous bottom layer, and calculates the frictional resistance increase rate FIR (%) or the frictional resistance increase ⁇ , thereby depending on the rough surface. This is a method for predicting an increase in frictional resistance.
- Rc is the average height of the roughness curve element
- Ra is the arithmetic average roughness, and these are measured according to JIS B0601: 2001 (ISO 4287: 1997). Since the average height Rc of the roughness curve element is the average of the roughness heights appearing in the cross-sectional curve, the exposure roughness projection area A is shown below using the roughness height Rc, RSm, and the viscous bottom layer height ⁇ s. It can be calculated in a procedure.
- the single exposed roughness projected area a exposed from the viscous bottom layer is a projected area of a cone, it becomes a triangular area of height h and base l. It is calculated using 0.5 ⁇ h ⁇ l as follows. Since l is calculated using RS in FIG. 4 and RSm ⁇ 2x, and h is calculated as Rc ⁇ s, the equation (3) is expressed using Rc and RSm. Is finally shown in the form (9).
- the exposure roughness projection area A is calculated in the form of (11) by multiplying the single exposure roughness projection area a exposed from the viscous bottom layer by the roughness number N per unit area calculated by the equation (10).
- Ra is the arithmetic average roughness, which is a value obtained by folding the roughness curve f (x) from the center line and dividing the area obtained by the roughness curve and the center line by the length, as shown in equation (12). Since it is calculated, it can be regarded as a projected area per unit length. Therefore, as shown in Expression (13), if ⁇ s is reduced, the exposure roughness projected area a exposed from the viscous bottom layer is obtained. Assuming that the number N per unit area of the projected area of the unit length is 1 / RSm in the same manner as the equation (10), the exposure roughness projected area A is calculated by the equation (15). Is done.
- Roughness Measurement Such roughness measurement is evaluated using a surface roughness measuring device such as a contact type, a non-contact type, a manual method, and an automatic method. Usually, a stylus type or a laser displacement type is preferable in terms of simplicity and the like. Above all, if the laser displacement meter uses a line laser (ultra-high-speed inline profile measuring instrument LJ-V7000 series) or the like, three-dimensional measurement can be performed quickly. The obtained data may be stored or analog / digital processed inside the displacement meter.
- LJ-V7000 series ultra-high-speed inline profile measuring instrument
- the cross-sectional curve As it is, but when there is an influence of waviness of a wavelength of 10,000 ⁇ m or more, the cut-off value (in accordance with JIS B 0601: 2001 (ISO 4287: 1997))
- a roughness curve can be obtained by inserting a high-pass filter having a wavelength ⁇ c of 10,000 ⁇ or more.
- the evaluation length and cut-off value ⁇ c required for accurately evaluating the roughness are 10,000 ⁇ m or more, and the measurement interval is 500 ⁇ m or less.
- the measurement interval is 500 ⁇ m
- the minimum wavelength that can be measured is 2,000 ⁇ m.
- the measurement error of the low wavelength roughness is increased, it is practically about 250 ⁇ m. If the measurement interval is reduced, it takes a long time to measure and, as a result, the influence of a wavelength with a low roughness height, which is not related to an increase in frictional resistance, appears.
- the measurement interval is desirable to change the measurement interval (resolution) according to the wavelength of roughness.
- the frictional resistance test is performed by any of the towing test, the circular tube test, the double cylinder test, and the cavitation water tank.
- the frictional resistance ⁇ r (N / m 2 ) of the rough surface at each speed when the roughness cylinder is rotated under the same conditions and the frictional resistance increase rate FIR (% ).
- the thickness of the viscous bottom layer ⁇ s at each speed is obtained by a frictional resistance test on the smooth surface.
- the frictional speed u * is calculated from the smooth surface frictional resistance ⁇ 0 at each speed by the equation (17), and the thickness is calculated by the equation (18).
- FIR (%) or A value that increases the correlation coefficient between ⁇ and the exposure roughness projection area A is selected.
- u * is the friction velocity
- ⁇ is the kinematic viscosity coefficient
- ⁇ is the fluid density
- the slope C in equation (19) varies depending on the type of roughness height R and the frictional resistance test method. A surface having different roughnesses was prepared in advance, and the frictional resistance was evaluated by a frictional resistance test with different flow speeds. The constant in equation (19) was calculated from the relationship between the projected roughness A and the measured FIR (%). Find C.
- Rc or Ra and the average length RSm of the roughness curve element are measured for the roughness surface using the constant C obtained in advance, and the exposure roughness is measured using the viscous bottom layer thickness ⁇ s at the smooth surface of the target flow velocity.
- the drag force (F) of the fluid is said to be proportional to the projected area S, the fluid density ⁇ , and the flow velocity V, and the drag coefficient C D is expressed by the equation (20) based on the roughness. Can be calculated. Therefore the frictional resistance increase ⁇ by roughness was calculated by the equation (21), a ⁇ and the force F, the frictional resistance coefficient C r roughness using exposure roughness projection area A and the flow velocity V and the fluid density ⁇ has the formula Calculated by (22).
- the flow velocity is halved at the center between the outer cylinder and the inner cylinder, and the flow velocity is simply calculated by Equation (23).
- the method for calculating the flow velocity is appropriately selected according to the friction resistance test method. Is possible.
- the surface performance evaluation apparatus uses the above-described prediction method, and measures the roughness R by the height R and the average length RSm of the roughness curve elements, and equations (2), ( 3) is used to calculate the exposure roughness projection area A, the frictional resistance increase rate FIR (%) using equation (19), and the frictional resistance increase ⁇ (N / m 2 ) using equation (24). ) Is provided.
- this surface evaluation apparatus it is possible to easily predict the increase rate of the frictional resistance on the roughness surface and to evaluate the surface performance.
- Example 1 EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is not limited to these Examples at all.
- Example 1 Using double cylinder test, 0.5 ⁇ (Rc ⁇ s) 2 / (Rc ⁇ RSm) is used as the exposure roughness projected area A.
- the average height Rc and roughness curve element of the element was calculated from the average length RSm and the viscous bottom layer thickness ⁇ s, and the relationship between the frictional resistance increase rate FIR (%) was evaluated.
- the surface roughness of the inner cylinder on which the coating film was formed was measured with a laser displacement meter starting from 5 mm to the lower part of the test body and measuring 58 lines at intervals of 5 mm up to the upper part. Displacement data was acquired every 250 ⁇ m, and 4,000 points of data were acquired between 1,000 mm. As a result, the measurement interval became 250 ⁇ m. After the measurement data for one line was divided into 33 pieces with an evaluation length of 30 mm, the sectional curve was calculated by subtracting the approximate curve based on the root mean square. Fifteen test inner tubes A to O were prepared.
- Rz maximum height roughness
- RZJIS ten-point average roughness
- Rc average height of roughness curve elements
- Ra arithmetic average roughness
- Rq root mean square roughness
- Table 1 shows the measurement results of Rz, RZJIS, Rc, Ra, Rq, Rsk, Rku and RSm in the cylinders A to O measured using the double cylinder device. Only the cylinder A in Table 1 has an extremely short wavelength, and the method with the above measurement interval of 250 ⁇ m has a low roughness and a long wavelength. Therefore, using a laser displacement meter with a measurement interval of 50 ⁇ m, 1 of 30 mm ⁇ 30 mm The location was remeasured.
- the frictional resistance increase rate FIR (%) at 500 to 1000 (rpm) of the inner cylinder on which each rough surface was formed was calculated by the equation (16) and shown in Table 4.
- the exposure roughness projected area A was calculated using Equation (1) using the thickness ⁇ s of the viscous bottom layer in Table 3 and the average height Rc of each cylindrical element in Table 1, and is shown in Table 6.
- Example 2 Friction Resistance Test Using (Ra- ⁇ s) / RSm as the exposed roughness projected area A
- the friction resistance measurement method and roughness measurement method use the method described in [Example 1].
- the exposure roughness projected area A was calculated using Equation (2) using the thickness ⁇ s of the viscous bottom layer in Table 7 and the average height Ra of the elements of each cylinder in Table 1, and is shown in Table 8.
- Example 4 Calculate the square of 0.5 ⁇ fluid density ⁇ ⁇ exposure roughness projection area A ⁇ flow velocity V using the flow velocity V, fluid density ⁇ , and the exposure roughness projection area A of Table 6 calculated in [Example 1].
- Table 10 shows. It should be noted that the flow velocity V used here is shown in the upper part of Table 10, assuming that the flow velocity is halved at the center between the outer cylinder and the inner cylinder in the case of the double cylinder test, using the formula (23). Yes.
- FIG. 9 shows an example of a surface roughness measuring instrument using a Keyence Corporation LJ-V7080 as a displacement meter measurement unit using a two-dimensional beamline laser and a Keyence Corporation optical scale VP-90 as a moving distance reading unit. is there.
- the displacement can be recorded at a measurement interval of about 50 ⁇ m using a light scale by a scale attached to the wheel, and a three-dimensional shape can be output.
- a three-dimensional measuring instrument that can quickly measure the surface roughness.
- the projected roughness area and quantity in the flow direction can be measured at once by this configuration, the exposed roughness projected area A can be obtained very quickly, so that data for resistance prediction can be acquired.
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Abstract
Description
流速が異なる流体と接する粗度波長が異なる粗面について、粘性底層厚さから露出した単位面積当たりの総露出粗度投影面積A(以下、「露出粗度投影面積A」という)を評価して、下記式(1)により摩擦抵抗増加率FIR(%)、または、下記式(2)により摩擦抵抗増加Δτを算出することを特徴とする粗面の摩擦抵抗予測方法。
式(2)中、係数Crは、流体密度ρ、露出粗度投影面積A、流速Vに依存する定数であり、予め粗度の異なる複数の粗面について流速Vを変えて摩擦抵抗試験を行い、摩擦抵抗増加Δτを測定し、式(2)の関係から求めたものである。なお摩擦抵抗増加Δτは粗面の摩擦抵抗τrと滑面の摩擦抵抗τ0の差τr-τ0である。)
ISO 4287:1997(JIS B 0601:2001)の規定に従い、粗度波長λとして粗さ曲線要素の平均長さRSm、粗度高さRとして、Rc(粗さ曲線要素の平均高さ)を測定し、式(3)を用いて算出した露出粗度投影面積Aの値を用いることを特徴とする[1]に記載の粗面の摩擦抵抗予測方法。
粗度高さR'として、Rz、Rzjis、RqまたはRaを測定し、各パラメーターと前記Rcとの傾きaを求め、Rc=a×R'(R'はRz、Rzjis、RqまたはRa)として変換して算出した露出粗度投影面積Aを用いることを特徴とする[2]に記載の粗面の摩擦抵抗予測方法。
ISO 4287:1997(JIS B 0601:2001)の規定に従い、粗度波長λとして粗さ曲線要素の平均長さRSm、粗度高さRとして、Ra(算術平均粗さ)を測定し、式(6)を用いて算出した露出粗度投影面積Aの値を用いることを特徴とする[1]に記載の粗面の摩擦抵抗予測方法
粗度高さR"として、Rz、Rzjis、RqまたはRcを測定し、各パラメーターとRaとの傾きaを求め、Ra=a×R" (R"はRz、Rzjis、RqまたはRc)として変換して算出した露出粗度投影面積Aを用いることを特徴とする[4]に記載の粗面の摩擦抵抗予測方法。
前記[1]~[5]のいずれかに記載の予測方法で、表面性能を評価する装置であって、
粗度高さR及び粗さ曲線要素の平均長さRSmを測定する測定部と、
露出粗度投影面積A、および、前記式(1)により摩擦抵抗増加率FIR(%)または前記式(2)により摩擦抵抗増加Δτを算出する算出手段を設けてなることを特徴とする表面性能評価装置。
前記測定部が、ロータリーエンコーダーあるいはリニアエンコーダーで移動距離を、2次元ビームを用いたレーザー変位計で変位を読み取り、三次元形状の粗度高さR及び粗さ曲線要素の平均長さRSmを測定する構成を具備することを特徴とする[6]に記載の表面性能評価装置。
粗度高さRとして、Rz、Rzjis、Rq、RcまたはRaを測定することを特徴とする[6]または[7]に記載の表面性能評価装置。
本発明は、粘性底層厚さから露出した単位面積当たりの総露出粗度投影面積Aを評価して、摩擦抵抗増加率FIR(%)、または、摩擦抵抗増加Δτを算出することで粗面による摩擦抵抗増加を予測する方法である。
図3に示す通り粗度波長が異なる粗面において、流速が変化すると粗度の影響を受けない厚さであるδsが変化し、露出粗度投影面積が変化する。高速になると粘性底層が薄くなり露出粗度投影面積Aが大きくなるため、摩擦抵抗増加率FIR(%)が大きくなると考えられる。同一流速の場合は粗度が大きくなると露出粗度投影面積Aが大きくなり、粗度波長が短くなると粗度数量が大きくなる為、露出粗度投影面積Aが大きくなり、この場合も摩擦抵抗増加率FIR(%)が増加すると考えられる。この粗度の高さ、波長、粘性底層の厚さと抵抗増加の関係が明らかになれば、粗面による摩擦抵抗増加を容易に予測することができると考え、本発明の完成に至った。
JIS B 0601:2001(ISO 4287:1997)の規定に従い、粗度高さRとしてRc(粗さ曲線要素の平均高さ)、Ra(算術平均粗さ)のいずれかを測定し、下記式(1)、(2)により、粘性底層からの単位面積当たりの総露出粗度投影面積A((以下、「露出粗度投影面積A」という))を算出する。
この単位長さの投影面積の単位面積当たりの個数Nを、前記式(10)と同様に、式(14)の通りを1/RSmとすると式(15)により露出粗度投影面積Aが算出される。
このような粗度の測定は接触式、非接触式、手動、自動などの表面粗度測定装置を用いて評価される。通常汎用され、また、簡便性などの点で触針式やレーザー変位式のものが好適である。中でも、レーザー変位計はラインレーザー(超高速インラインプロファイル測定器 LJ-V7000シリーズ)等を用いれば、三次元測定を迅速に行うことができる。得られたデータは、保存するか、もしくは変位計内部で、アナログ/デジタル処理してもよい。
水流摩擦抵抗を計測する試験法であれば曳航試験、円管試験、二重円筒試験、キャビテーション水槽、いずれの方法で摩擦抵抗試験を行う。二重円筒装置を用いた場合、予め外筒を500rpm~1000rpmの回転数で回転させた時に50rpm毎に鏡面の内筒に働くトルクから単位面積当たりの滑面摩擦抵抗τ0(N/m2)を求め、ついで粗度円筒を同条件で回転させたときの各速度での粗面の摩擦抵抗τr(N/m2)を求め、下記式(16)より摩擦抵抗増加率FIR(%)を計算する。
一般的に流体の抗力(F)は、投影面積Sと流体密度ρ及び流速Vに比例すると言われており、粗度による式(20)のように抗力係数CDを算出することができる。そこで粗度による摩擦抵抗増加Δτを式(21)により算出し、Δτを前記抗力Fとし、流速Vと流体密度ρと露出粗度投影面積Aを用いて粗度の摩擦抵抗係数Crが式(22)により算出される。二重円筒試験の場合外筒と内筒の中央で流速が半分になると仮定して、式(23)により流速を簡易算定するが、流速算出の方法は摩擦抵抗試験の方法に応じて適宜選択可能である。
あらかじめ算出した粗度抵抗係数Cr、露出粗度投影面積A、流体密度、流速Vを用いて、式(24)を用いて粗度による摩擦抵抗増加Δτ(N/m2)の算出が可能となり、粗面の摩擦性能を評価することもできる。
以下、本発明を、実施例をもとにさらに詳しく説明するが、本発明はこれらの実施例に何ら限定されるものではない。
[実施例1]
二重円筒試験を用い露出粗度投影面積Aとして、0.5×(Rc-δs) 2 /(Rc×RSm)を利用
二重円筒装置を用い、要素の平均高さRc及び粗さ曲線要素の平均長さRSmと粘性底層厚さδsから露出粗度投影面積Aを算出し摩擦抵抗増加率FIR(%)の関係を評価した。
対象流体の粘性底層厚さδsが10μm(無次元化距離y+=4.0)、Rcが40μm、波長が3000μmの場合、式(2)により算出される露出粗度投影面積Aは0.0075(m2)となりC=1274により式(19)により算出されるFIR(%)は9.6%となる。
摩擦抵抗試験 露出粗度投影面積Aとして(Ra-δs)/RSmを利用
摩擦抵抗測定方法及び粗度測定方法は、[実施例1]に記載の方法を用いる。本実施例では無次元化距離(y+=2.5)として粘性底層の厚さδsを、式(17)、(18)を用いて算出し、表7に示した。表7の粘性底層の厚さδs及び、表1の各円筒の要素の平均高さRaを用いて式(2)を用いて、露出粗度投影面積Aを算出し、表8に示した。
表6の露出粗度投影面積Aを横軸に、表2のFIR(%)を縦軸に示したグラフは図2となりC=1800となった。
本実施例を利用した、抵抗予測例を示す。
表1に示した各円筒の粗度パラメーターについて、Rz、Ra、Rq、RZJISのRcとの相関を図5、Rz、Rc、Rq、RZJISのRaとの相関を図6に示した。いずれも相互に高い相関性を示す為、どの粗度高さRを用いて評価しても良い。このことから粗度高さRとしてRz、Rzjis、Rqを用いる場合には、それぞれのパラメーターとRc、あるいはRaとの傾きa、あるいはa'を利用して、
RをRc=a×R または Ra=a'×R
として変換して、式(1)、式(2)による投影面積の算出に利用することが出来る。
流速V、流体密度ρ、[実施例1]で算出した表6の露出粗度投影面積Aを用いて0.5×流体密度ρ×露出粗度投影面積A×流速Vの二乗を算出し、表10に示した。尚、ここで用いた流速Vは二重円筒試験の場合外筒と内筒の中央で流速が半分になると仮定して、式(23)により簡易算定したものを用い、表10上部に示している。表10の0.5×流体密度ρ×露出粗度投影面積A×流速Vの二乗を横軸に、表9のΔτを縦軸に示したグラフ図7によりCr=0.0556となった。
密度ρ=1023.95(kg/m3)の対象流体の流速が8.4(m/sec)の場合、粘性底層厚さδsが10μmとし(無次元化距離y+=4.0)、Rcが40μm、波長が3000μmの場合、式(2)により算出される露出粗度投影面積Aは0.0075(m2)となりCr=0.0556により式(24)により算出される摩擦抵抗増加Δτは15(N/m2)となる。
粗面と滑面の摩擦抵抗増加Δτ(N/m2)を表2の滑面摩擦抵抗τ0、及び表3の粗面摩擦抵抗τrを用いて式(21)により算出し、表9に示した。流速V、流体密度ρ、[実施例2]で算出した表8の露出粗度投影面積Aを用いて0.5×流体密度ρ×露出粗度投影面積A×流速Vの二乗を算出し、表11に示した。尚、ここで用いた流速Vは二重円筒試験の場合外筒と内筒の中央で流速Vが半分になると仮定して、式(23)により簡易算定したものを用い、表11上部に示している。表11の0.5×流体密度ρ×露出粗度投影面積A×流速Vの二乗を横軸に、表9のΔτを縦軸に示したグラフ図8によりCr=0.0782となった。
密度ρ=1023.95(kg/m3)の対象流体の流速が8.4(m/sec)の場合、対象流体の粘性底層厚さδsが6.5μm(無次元化距離y+=2.5)、Raが20μm、波長が3000μmの場合、式(2)により算出される単位面積当たりの総露出粗度投影面積Aは0.0045(m2)となりCr=0.0782により式(24)により算出される摩擦抵抗増加Δτは12.7(N/m2)となる。
図9はキーエンス社製のLJ‐V7080を、2次元ビームラインレーザーを用いた変位計の測定部、キーエンス社の光スケールVP‐90を移動距離の読み取り部とした表面粗度測定器の例である。車輪に取り付けたスケールにより光スケールを用いて、測定間隔50μm程度で変位を記録することができ、三次元形状を出力可能である。この構成により、迅速に表面粗度測定が実施可能な三次元測定器が実現可能である。また本構成により流れ方向に対する粗度投影面積と、数量を一度に測定可能である為、極めて迅速に露出粗度投影面積Aを求めることが出来るので、抵抗予測の為のデータを取得できる。
Claims (8)
- 流速が異なる流体と接する粗度波長が異なる粗面について、粘性底層厚さから露出した単位面積当たりの総露出粗度投影面積A(以下、「露出粗度投影面積A」という)を評価して、下記式(1)により摩擦抵抗増加率FIR(%)、または、下記式(2)により摩擦抵抗増加Δτを算出することを特徴とする粗面の摩擦抵抗予測方法。
式(2)中、係数Crは、流体密度ρ、露出粗度投影面積A、流速Vに依存する定数であり、予め粗度の異なる複数の粗面について流速Vを変えて摩擦抵抗試験を行い、摩擦抵抗増加Δτを測定し、式(2)の関係から求めたものである。なお摩擦抵抗増加Δτは粗面の摩擦抵抗τrと滑面の摩擦抵抗τ0の差τr-τ0である。) - ISO 4287:1997(JIS B 0601:2001)の規定に従い、粗度波長λとして粗さ曲線要素の平均長さRSm、粗度高さRとして、Rc(粗さ曲線要素の平均高さ)を測定し、式(3)を用いて算出した露出粗度投影面積Aの値を用いることを特徴とする請求項1に記載の粗面の摩擦抵抗予測方法。
- 粗度高さR'として、Rz、Rzjis、RqまたはRaを測定し、各パラメーターと前記Rcとの傾きaを求め、Rc=a×R'(R'はRz、Rzjis、RqまたはRa)として変換して算出した露出粗度投影面積Aを用いることを特徴とする請求項2に記載の
粗面の摩擦抵抗予測方法。 - ISO 4287:1997(JIS B 0601:2001)の規定に従い、粗度波長λとして粗さ曲線要素の平均長さRSm、粗度高さRとしてRa(算術平均粗さ)を測定し、式(6)を用いて算出した露出粗度投影面積Aの値を用いることを特徴とする請求項1に記載の粗面の摩擦抵抗予測方法。
- 粗度高さR"として、Rz、Rzjis、RqまたはRcを測定し、各パラメーターとRaとの傾きaを求め、Ra=a×R"(R"はRz、Rzjis、RqまたはRc)として変換して算出した露出粗度投影面積Aを用いることを特徴とする請求項4に記載の粗面の摩擦抵抗予測方法。
- 請求項1~5のいずれかに記載の予測方法で、表面性能を評価する装置であって、
粗度高さR及び粗さ曲線要素の平均長さRSmを測定する測定部と、
露出粗度投影面積A、および、前記式(1)により摩擦抵抗増加率FIR(%)または前記式(2)により摩擦抵抗増加Δτを算出する算出手段を設けてなることを特徴とする表面性能評価装置。 - 前記測定部が、ロータリーエンコーダーあるいはリニアエンコーダーで移動距離を、2次元ビームを用いたレーザー変位計で変位を読み取り、三次元形状の粗度高さR及び粗さ曲線要素の平均長さRSmを測定する構成を具備することを特徴とする請求項6に記載の表面性能評価装置。
- 粗度高さRとして、Rz、Rzjis、Rq、RcまたはRaを測定することを特徴とする請求項6または7に記載の表面性能評価装置。
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Non-Patent Citations (2)
Title |
---|
HIROHISA MIENO ET AL.: "Friction Increase due to Roughness of Ship Hull Paint", JOURNAL OF THE JAPAN INSTITUTE OF MARINE ENGINEERING, vol. 48, no. 3, 1 May 2013 (2013-05-01), pages 300 - 307, XP055476883 * |
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