US3890835A - Chemical recording of flow patterns - Google Patents

Chemical recording of flow patterns Download PDF

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US3890835A
US3890835A US269746A US26974672A US3890835A US 3890835 A US3890835 A US 3890835A US 269746 A US269746 A US 269746A US 26974672 A US26974672 A US 26974672A US 3890835 A US3890835 A US 3890835A
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layer
dye
eloxal
flow
treating
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Richard Dotzer
Winfried Plundrich
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Siemens AG
Siemens Corp
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Siemens Corp
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C25D11/18—After-treatment, e.g. pore-sealing
    • C25D11/24—Chemical after-treatment

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  • ABSTRACT The flow pattern of a fluid over a surface can be determined by treating the surface to form a reactive layer, entraining in the fluid a reagent compound which is capable of chemically changing the reactive layer, and then passing the fluid over the reactive layer which is to be examined.
  • This method is illustrated by treating an aluminum surface of a blade member (such as that in a vacuum cleaner blower) or adjacent structural members to form a thin aluminum oxide film by anodic treatment.
  • the microporous film which is formed is then impregnated with an organic dye.
  • An air stream containing a reactive substance, such as acid vapors, is passed over the treated blade member.
  • the acid vapors react with the dye and/or the oxide layer and produce a visible pattern upon the blade which is characteristic of the boundary layer flow of the air stream.
  • An examination of the visible pattern is of assistance in determining the proper design and operating characteristics of the blade.
  • the visible pattern may be formed or preserved by chemical post-treatment, such as etching to leach out dye from unreacted portions of the layer and to provide a more permanent record for subsequent use.
  • the microporous aluminum oxide layer can be treated with a fluid stream containing a reactive substance to characteristically change the layer, followed by treatment with a dye to form the visible pattern of the boundary flow.
  • This invention is directed to treating a reactive surface with a fluid containing a reagent which interacts with the reactive surface; a dye substance added to the reactive surface prior to, or after contact of the surface with the fluid, provides a visible record of the flow pattern of the fluid over the surface.
  • the eloxal layer and the dye that may be present undergo characteristic changes which are dependent on the local concentration of the reagent in the fluid.
  • the chemical reagent records the flow pattern of the boundary layer flow very accurately on the eloxal layer, almost with molecular resolution.
  • This process can thus be termed a method of chemically recording flow patterns of boundary layer flow.
  • the process is referred to herein as chemical recording (or chemigraphy), and the records obtained are called chemigraphs (or chemical recordings).
  • Very highcontrast chemigraphs can be obtained in color, or in several colors. they are referred to as eloxal-colorlayer chemigraphs.”
  • the eloxal layer is illustrative of the type of microporous layer which is preferred.
  • the microporous layer can be impregnated with a dye to produce a visible recording of the flow layer upon treatment with a fluid containing a dye-reactive reagent or a reagent which seals the pores of the layer followed by leaching of the unsealed dye.
  • an undyed microporous layer can first be treated with a reagent which reacts with the microporous layer to selectively seal its pores and then a dye can be used to produce a visible pattern of the fluid flow.
  • the microporous eloxal layer is preferred, but other microporous oxides or synthetic layers may be used.
  • the method of this invention is particularly suited for the recording of steady-state flow conditions in blowers. It allows the recording of existing flow conditions (flow profiles) directly, unaltered and reproducibly on the portions of the surfaces which are contacted by the air flow. Thus the air stream records itself on the adjoining surface portions of the parts of the blower.
  • FIG. 1 shows the chemical recording of the boundary layer flow of a radial rotor with straight, centrically or radially. respectively. arranged blades.
  • FIG. 2 shows the chemical recordings of a so-called parallel-blade rotor with blades curved in sicklefashion.
  • FIGS. 3, 4 and 5 show chemical eloxal-red-layer recordings, of the first rotor of the blower, recorded at 30% output of the blower motor and contrast-etched by means of sodium hydroxide.
  • FIG. 3 shows the base plate and FIG. 4, the cover plate. The concave side of the curved, sickle-shaped blade is shown in FIG. 5.
  • FIGS. 6 to 11 show chemical recordings of the boundary layer flow of different aerodynamic bodies on small eloxal-dye-layer base plates.
  • FIG. 12 shows a boundary flow layer of air directed at an angle against a sheet member.
  • FIGS. 1 and 2 show in each case the inside surface of the lower circular disc (base plate) of the first rotor wheel of a two-stage blower and show clearly the contact edges of the removed blades. Both rotors were in rotation during the chemical recording in a clockwise direction, at a speed of rotationof the blower of 12,000 rpm. They were discolored in a manner characteristic of the flow.
  • the method according to this invention is particularly well suited for making visible the boundary layer flow of moving fluid media, particularly of air. gases and vapors of high flow velocity. such as they appear in parts of blowers. It is used to advantage for the recording of flow profiles in the rotors, stators and housings of vacuum cleaner blowers, rotary flow dust separators, counter-jet pulverizers and cyclone separators.
  • the method designated herein as chemigraphic recording of boundary layer flow provides very durable. high-contrast flow patterns (chemigraphs). With appropriate pre-treatment of the surfaces it can also be applied to parts which do not consist of aluminum material. By evaluating the chemigraphs of the surface portions adjoining the flowing fluid. informative insights can be obtained into the spatial flow processes.
  • Numerous reagents can be readily and uniformly encorporated in a fluid medium to react with and modify the color of a dye in an eloxal layer. Strong acids and bases, and reactive gases are suitable.
  • Nitric acid vapors can be added as the chemical reagent to the air stream, and one can record chemically for eight minutes or longer, if required.
  • the chemographic recording then shows immediately the contrast reproduced in the image and is very durable.
  • Ozone also can be added advantageously to the air stream as the chemical reagent. As almost all aluminum dyes are by oxidation decomposed, i.e., modified or destroyed and thereby bleached, full-range chemical recordings can be obtained in a few minutes with an oxonecontaining air stream. With somewhat higher ozone concentrations, fractions of a minute are sufficient. For example.
  • a surface can be chemically recorded for several minutes with a fluid containing nitric acid vapors (or with hydrogen chloride mist). Then, if desired, the parts can be left at room temperature for several hours, i.e., about 8 hours for a setting of the chemically recorded layer, and subsequently placed in a dye bath for about 10 minutes. After rinsing with water, the chemical recordings are finished. The portions not contacted by the air stream, which therefore have not been chemically recorded, will have absorbed dye and thereby are clearly distinguished from the colorless chemically recorded boundary layer flow areas.
  • the reagent in the fluid can be of different functional types. one which reacts with the dye in the eloxal layer to change the color of the dye, or which reacts with the eloxal layer to seal its ports, or a combination of such reactions.
  • the choice of reagent can be readily made from those known to react with dyes and/or to seal microporous structures such as an eloxal layer.
  • a further, particularly advantageous embodiment is to chemically post-treat the eloxal layer which is differentially altered by the method of this invention.
  • this process is called contrast etching.
  • a reduction of the exposure time is thereby achieved (to 3 to 5 minutes) and a chemigraph of even higher contrast is obtained, as is shown in FIGS. 3 to 5.
  • any aluminum dyes can be used, although the strongly dyed basic colors red, yellow and blue (and as a mixed color, green) are preferred because they provide sharp contours and clear contrast.
  • the chemical post-treatment can be a brief etching, which can be performed with acids as well as with alkaline solutions.
  • Immersion times of between 5 and 30 seconds are sufficient for the etching process; with immersion times of over five minutes fuller decomposition of the chemigraphic image will occur. If sodium hydroxide is used, immersion times of less than 5 seconds are sufficient. For 20% sodium hydroxide, for instance. an immersion time of three seconds has been found suitable.
  • the surface is rinsed liberally with Water and finally dried between filter paper.
  • etching media which have been found are concentrated aqueous ammonia and particularly, nitric acid and sulfuric acid with the immersion times mentioned above. It has been found advantageous to chemically record and contrast-etch with the same acid.
  • the chemical recording is perferably done with nitric acid vapor, and this acid is then used for the contrast etching.
  • a concentration of about 65% acid produces clear contrast between the chemically recorded eloxal-dye- ]ayer areas and the colorless parts of the surface which have not been exposed.
  • the etching technique is also useful where the reagent in the fluid does not visibly change the color of the dye.
  • the reagent may only serve to seal the microporous structure of a dyed eloxal layer at characteristic areas of the boundary flow layer. Upon etching of leaching the dye is removed from the unsealed areas to provide a visible pattern.
  • the dyeing of the aluminium layer can preferably by carried out with two or more aluminium dyes.
  • the con trast of the chemical recording is thereby enhanced.
  • the microscopic depressions existing in the eloxal layer are first filled partially with the one dye, and then partially with the other dyes. They may, for instance. first be filled with a blue dye and then on top with a yellow dye. The resulting color effect is green. In chemical recording, the yellow dye is partially altered or decomposed. respectively, and at other points, all dyes are affected, depending on the concentration of the chemical reagent caused by the flow. Thus a flow pattern differentiated by green-blue-colorless is obtained.
  • the chemical recording sensitivity of the eloxal dye layer can be reduced by partial sealing of the microscopic depressions.
  • the surface can be sealed in boiling water for minutes to 1 hour.
  • Eloxal-red-layer chemigraphs have been found to be excellent on the basis of their color contrast, which can be obtained by dyeing the eloxal layer with a red dye, and sealing and exposing with nitric acid-containing vapors.
  • Suitable red dyes are, for instance, the following:
  • indigo and its derivates are particularly well suited as are Redox indicator dyes such as, for instance, methylene blue, Congo red, toluylene blue, thiazine, safranin T, and neutral red. Furthermore, dyes which change by oxidation in air have been proven highly suitable. Steamvapors can also be used as the chemical reagent to react with the dyeable substance or eloxal layer.
  • the reagent compound. in vaporous or gaseous form. is readily dispersed in and mixed with the fluid stream by conventional means.
  • the fluid stream may be passed over a vat of rising vapors or a gas generator can direct reagent gases or vapor into the fluid stream.
  • a baffle network or mixing device may be used if desired to ensure even dispersion of the reagent in the fluid stream.
  • the eloxal layers prepared by customary methods through anodic oxidation of the surface are suitable for carrying out the method of this invention.
  • the wellknown d-c sulfuric acid method (GS method) is the most widely employed and most inexpensive process for the anodic oxidation of aluminum and aluminum alloys.
  • the eloxal layers produced thereby have a microporous or honeycomb-like fine structure. These non-conducting, mechanically strong surfaces are particularly resistant against atmospheric influences and accept dye very well.
  • the dye molecules are impregnated into the microscopic depressions of the eloxal layer, which are about A in diameter and about l0 ,um depth.
  • the dye is therefore not on the surface but in the eloxal layer and is not carried away by gas even of very high flow velocities.
  • the eloxal surface presents a very homogenous and, if required, even polishable surface, which does not interfere with the flowing media. It is also thermally stable.
  • an eloxal-type coating can also beused.
  • commercial coating are also made by treating the aluminum in an electrolyte of chromic acid, oxalic acid, or oxalic acid mixed with sulfuric acid.
  • Artificial oxide coatings can be formed in aluminum articles by chemical treatment as well as by electrochemical treatment. These chemical coatings are not as thick or as hard nor as abrasionresistant as anodic coatings, but for many purposes they are adequate.
  • the chemigraphic recordings can be made of practically unlimited durability by sealing after the chemigraphic exposure. This can be accomplished; for instance, by sealing for 30 minutes in boiling water or in a commercially available sealing salt bath.
  • the original chemigraphs obtained by the method of this invention can be preserved by means of photography in color or in black and white.
  • the photographs can also be evaluated quantitatively by means of photometry.
  • the chemigraphs can also be used as standards of proper flow patterns for purposes of matching new blade or structural units with a known standard of a flow pattern that has proven to be effective.
  • the eloxal layer may consist of an anodically oxidized. surface of an aluminum part.
  • a particularly advantageous embodiment of the method according to the invention is based on the use of a self-adhering eloxadized aluminum foil. In many cases it may be found to be particularly advantageous to dye the eloxal layer.
  • an aluminum foil or sheet coated with an eloxal dye layer can be cemented on to the surface of the part or equipment for carrying out the method of this invention.
  • a test piece can also be aluminum-plated by electro-deposition and subsequently eloxadized.
  • Rotors or blowers of brass or sheet steel can, for instance, be aluminum-plated by electroplating, eloxadized and then dyed and chemically recorded on by the method of this invention.
  • the method according to this invention becomes practically independent of the kind of material of the part or equipment which is to be tested for its aerodynamic characteristics.
  • any kind of aluminum foil is suitable. which is eloxal-coated on one or both sides, and is undyed or dyed with a suitable aluminum dye.
  • the foils are cemented to the surface portions of the part or equipment which is of interest from a flow point of view, and the boundary layer flow profiles are recorded by the method according to this invention.
  • the impregnated paper-laminated, self-adhering aluminum foil which is commercially available in sheet form or as yard goods, is particularly well suited for carrying out the method described herein.
  • the foil is cut to conform to the surface portions to be tested by chemical recording and affixed to the surface of the object with its adhesive side. After the chemical recording, the selfadhering foil, which has the flow profiles recorded in the dyed eloxal layer, can be stripped off the surface.
  • the foil can be preserved for purposes or comparison or documentatiomand can be mounted on a rigid support, such as cardboard, for ease of handling.
  • the self-adhering eloxaldye-layer aluminum foil is applicable regardless of the base material of the part or equipment to be chemically recorded.
  • the use of such foil furthermore makes the method independent of anodizing and dyeing equipment, and it can be used at any location.
  • the boundary layer flow at given portions of the surface of parts or equipment can be chemically recorded with different foil pieces as many times as desired under different flow conditions and can be compared very well visually by juxtaposition of the chemical recordings on the foil pieces and evaluated with respect to changes that may have occured.
  • the self-adhering eloxal-dye-layer aluminum foils can be cemented on non-planar, convexor concave-cylindrical surfaces or differently shaped surface portions, and the chemically recorded parts of the foils can be cemented side-by-side on flat cardboard for comparison purposes.
  • the foil also offers the possibility to investigate, on the basis of different aluminum dyes and chemical recording reagents, the surface areas of interest under the same flow conditions by means of chemical recording methods which record with different speed and resolution, and so to obtain more information regarding the flow process.
  • an eloxal layer can be formed with an acidreactive dye and basic-reactive dye(or more generally, two or more dyes which are subject to distinguishable visible changes at different pHs).
  • a first flow condition can then be established with a fluid containing an acid entrained therein and subsequently a second flow condition (i.e. a faster rate) can be established with the fluid containing a base entrained therein.
  • a second flow condition i.e. a faster rate
  • EXAMPLE I A l-mm thick sheet of Raffinal (a high-purity aluminum sheet), which had eloxadized to a thickness of about ,um by the GS method, was dyed for 10 minnutes at room temperature in a dye bath with an Azodyestuff like Al True Red B3LW (made by Sandoz) at a concentration of 5 g/liter. From a nozzle of 2 mm diameter (placed onn the left side) the eloxal-dye layer was exposed to an air stream of 500 liter/h at an angle of inclination of 5C. The air stream contained at the chemical reagent the vapors carried along by it from the gas space above 65-% nitric acid at room temperature.
  • Dyeing in a dye bath with 5 g/liter of an Azo-dyestuff like Al True Red B3LW(made by Sandoz); 10 minutes at room temp.;
  • Exposure time 8 minutes at a suction rate of 32 liter/sec of air.
  • the eloxal-red-layer chemigraph obtained corresponds to that of FIGS. 1 and 2.
  • a high-contrast chemigraph can also be obtained by a 3-min heat treatment at 100C in a drying cabinet, and also by contrast etching, as described above.
  • Dyeing 3,5 g/liter of an Indigo-dyestuff like Al Blue LLW; 10 minutes at room temperature
  • Chemical reagent Ozone, approximately ml of 0;
  • Exposure time 1 minute at a suction rate of 32 liter/- sec of air;
  • Exposure time 5 minutes at a suction rate of 18.5 liter/sec of air;
  • Etching medium 65-% NHO,-,:
  • Dyeing 3.5 g/liter of an Indigo-dyestuff like Al Blue LLW, 2.5 min at room temp.,
  • Exposure time 5 minutes at a suction rate of 18.5 liter/sec of air;
  • Etching medium 65-% HNO Etching time: 10 sec, then liberal rinsing with water;
  • Aerodynamic body model (drop 1, cylinder 2, cup 3) between sheet metal surfaces (4, 5, and 6 respectively) in the flow channel.
  • the aerodynamic bodies of the same cross section X 10 mm) exhibit different flow resistance due to their different shapes, which can be made visible chemigraphically via the width of the pressure head zone;
  • Pre-treatment TRINORM Al degreasing; chemical burnishing; GS- eloxation for minutes;
  • Dyeing in a dye bath with 5 g/liter of an Azo-dyestuff like Al True Red B3LW (made by Sandoz); 7 minutes at room temperature;
  • Exposure time 2 min at a suction rate of 7 liter/sec of air;
  • EXAMPLE 7 Eloxal-red-layer chemigraph according to FIGS. 9 to 11 were obtained with material, pre-treatment, dyeing, chemical reagent and exposure time as in Example 6.
  • the objects were a wing profile 7, triangular wedge 8 and an asymmetrical angle piece 9 as model forms between sheet metal surfaces (10, 11 and I2, respectively) in a flow channel.
  • EXAMPLE 8 An eloxal-red-layer chemigraph with contrast etching was prepared by using the following.
  • Pre-treatment Aluminium-plated by electrodeposition (approx. 25 ,um of Al and eloxadized (eloxal layer about 8 am thick);
  • Dyeing in a dye bath with 5 g/liter of an Azo-dyestuff like A] True Red B3LW; made by Sandoz) 8 minutes at room temperature;
  • Exposure time 3 minutes at a suction rate of 32 liter/sec of air;
  • Etching medium 65-% HNO Etching time: 10 sec, then liberally rinsing with water.
  • a chemigraph with red-colorless contrast was obtained as with the P-wheels made entirely of aluminium, i.e., the eloxadized and dyed electro-deposited aluminium corresponds fully to a equivalent eloxal-dye layer and accordingly produces fully equivalent'chemigraphs.
  • Pre-treatment Degreasing in TRINORM Al, eloxa dizing form 30 min;
  • Exposure time 5 minutes at a suction rate of 32 liter/sec of air;
  • Settling time About 8 hours at room temperature
  • Dyeing 8 g/liter of an Indigo-dyestuff like Blue LLW;
  • the vacuum cleaner blower is a two-stage blower. Two rotor wheels, which are mounted in tandem on a shaft and are separated from each other by a stationary guide vane wheel, are driven by an electric motor. The air entering the first rotor wheel centrally is accelerated radially outward, is deflected at the housing and is fed through the guide vane wheel inward to the second rotor wheel, which accelerates the air again radially outward.
  • the two rotor wheels have the same shape and each consist of two circular discs which are rigidly connected by six curved, sickle-shaped, radially and symmetrically arranged webs, the so-called rotor blades. With a circular disc diameter of mm, the rotor blades are 8 mm high and are riveted by means of suitable tabs firmly to the circular discs.
  • the guide vane wheel which, with a diameter of 150 mm, is somewhat larger, looks similar, and consists likewise of two circular discs perforated in the center, which are firmly connected with each other by eight, 8 mm high guide vanes in a similar manner.
  • the guide vanes are straight webs, symmetrical, but are not arranged centrically about the Center.
  • the rotor wheels are fixed on the shaft of the electric motor by means of a balancing nut and can reach up to 20,000 r.p.m.
  • the parts of the blower and the electric motor are enclosed by a housing with a cover and they constitute the vacuum cleaner blower.
  • the rotor wheel and the guide vane wheel are made of aluminum.
  • the chemigraphs obtained give information regarding the parts of the blower, the influence of the shape of the blades, the inner and outer attack angle of the blades, the shape of the entrance openings and, in the last analysis, information regarding the flow distribution and noise generation in the flow spaces between the blade and disc surfaces. They make it therefore possible to optimize the blower parameters and to improve the blower efficiency without increasing the noise level.
  • EXAMPLE 1 A sheet, 500 X 700 mm, of aluminum foil from JACKSTAEDT and Company, Wuppertal-E, with about 50,u.m of aluminum, with shiny aluminum surface (WI-CA 1 52125) or matte (WI-52124) and laminated on one side with adhesive and removable impregnated paper, is freed of the thin protective lacquer film applied for manufacturing reasons by means of dischloromethane. ln order to remove the last lacquer residue, the laminated aluminum foil is briefly immersed in diluted sodium hydroxide to and subsequently thoroughly rinsed in water. Any degreasing that may be necessary is done by immersion for 10 to 20 seconds in TRINORM Al (Schering).
  • the aluminum foil which is laminated on one side, is then anodically oxidized in the well-known d-c sulfuric-acid GS eloxadizing bath at 18C for minutes with a current density of 1.5 A/dm at a voltage of 16 V, and an eloxal layer of 10 to 12 um thickness is produced.
  • the aluminum foil, now coated with an eloxal layer is washed thoroughly for 5 to 10 minutes in water and dyed red for 10 minutes at room temperature in a dye bath with an Azo-dystufflike Aluminum True Red B3LW (SANDOZ AG, Basel) at a dye concentration of 5 g/liter.
  • SANDOZ AG Azo-dystufflike Aluminum True Red B3LW
  • the eloxal-red-layer aluminum foil is wiped off with filter paper and is allowed to dry at room temperature in clean air. The unsealed. self-adhering aloxal-red-layer aluminum foil is now ready for the chemical recording of boundary layer flow.
  • the inner wall of a glass tube of 30 cm length and 10 cm side diameter is coated with the self-adhering eloxal-red-layer aluminum foil, after the calculated area was first cut out from the 500 X 700 mm sheet and the impregnated paper foil stripped off. In order not to contaminate the eloxal-red-layer in handling, it is recommended to use clean protective gloves.
  • the boundary layer flow within the tube was determined from an air jet with a discharge orifice of 2 mm in diameter, inclined from the axis of the tube.
  • the flow profile can be made permanently and clearly visible by removing it from the wall of the glass tube, covering the adhesive with the impregnatedpaper foil, and contrast etching the chemigraphic image.
  • the finally sealed chemigraphic picture can then be mounted and is permanently available for evaluation and comparison.
  • the inside wall of the glass can be covered again with a self-adhering eloxal-red-layer aluminum foil made under the same conditions and chemigraphs can be recorded under different flow conditions.
  • a method of chemically recording the flow pattern of a fluid over a surface which comprises:
  • treating comprises electro-depositing aluminum upon said surface and treating said aluminum to form an aluminum oxide layer.

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  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
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  • Indicating Or Recording The Presence, Absence, Or Direction Of Movement (AREA)
  • Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
US269746A 1971-07-07 1972-07-07 Chemical recording of flow patterns Expired - Lifetime US3890835A (en)

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DE2133835A DE2133835C3 (de) 1971-07-07 1971-07-07 Verfahren zum chemischen Aufzeichnen von Grenzflächenströmungen

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Cited By (11)

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Publication number Priority date Publication date Assignee Title
US3978734A (en) * 1974-09-23 1976-09-07 Siemens Aktiengesellschaft Method for recording stationary flow patterns at boundary surfaces
US4250249A (en) * 1977-09-14 1981-02-10 Siemens Aktiengesellschaft Method for developing residual-moisture photographs
US4259431A (en) * 1979-03-26 1981-03-31 Siemens Aktiengesellschaft Method for making stationary heat transfer coefficient fields visible by photochemical means
US4346166A (en) * 1980-03-04 1982-08-24 Siemens Aktiengesellschaft Method of making families of steady-state heat transfer coefficient curves visible by photochemical means
US4361644A (en) * 1980-03-04 1982-11-30 Siemens Aktiengesellschaft Method for recording flow boundary layers in liquid media
US4380170A (en) * 1979-07-16 1983-04-19 Siemens Aktiengesellschaft Process for the chemical plotting of boundary layer flows, and chemigraphy materials for the practice thereof
US4384039A (en) * 1981-03-17 1983-05-17 Siemens Aktiengesellschaft Method for recording local boundary-layer flow-line directions in liquid media
US5070729A (en) * 1990-12-03 1991-12-10 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Multi-colored layers for visualizing aerodynamic flow effects
US5359887A (en) * 1992-08-03 1994-11-01 Mc Donnell Douglas Corp Pressure sensitive paint formulations and methods
US5544524A (en) * 1995-07-20 1996-08-13 The United States Of America As Represented By The Secretary Of The Navy Apparatus and method for predicting flow characteristics
US20120144911A1 (en) * 2010-12-08 2012-06-14 Michel Moliere Wind tunnel for studying vaporization of liquids

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10319943A1 (de) * 2003-05-02 2004-11-18 Ald Vacuum Technologies Ag Verfahren zur Sichtbarmachung von Grenzflächenphänomenen an der Oberfläche eines Bauteils

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3753652A (en) * 1970-02-13 1973-08-21 Ciba Geigy Ag Method of recording liquid flow over a solid surface

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3753652A (en) * 1970-02-13 1973-08-21 Ciba Geigy Ag Method of recording liquid flow over a solid surface

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3978734A (en) * 1974-09-23 1976-09-07 Siemens Aktiengesellschaft Method for recording stationary flow patterns at boundary surfaces
US4250249A (en) * 1977-09-14 1981-02-10 Siemens Aktiengesellschaft Method for developing residual-moisture photographs
US4259431A (en) * 1979-03-26 1981-03-31 Siemens Aktiengesellschaft Method for making stationary heat transfer coefficient fields visible by photochemical means
US4380170A (en) * 1979-07-16 1983-04-19 Siemens Aktiengesellschaft Process for the chemical plotting of boundary layer flows, and chemigraphy materials for the practice thereof
US4346166A (en) * 1980-03-04 1982-08-24 Siemens Aktiengesellschaft Method of making families of steady-state heat transfer coefficient curves visible by photochemical means
US4361644A (en) * 1980-03-04 1982-11-30 Siemens Aktiengesellschaft Method for recording flow boundary layers in liquid media
US4384039A (en) * 1981-03-17 1983-05-17 Siemens Aktiengesellschaft Method for recording local boundary-layer flow-line directions in liquid media
US5070729A (en) * 1990-12-03 1991-12-10 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Multi-colored layers for visualizing aerodynamic flow effects
US5359887A (en) * 1992-08-03 1994-11-01 Mc Donnell Douglas Corp Pressure sensitive paint formulations and methods
US5544524A (en) * 1995-07-20 1996-08-13 The United States Of America As Represented By The Secretary Of The Navy Apparatus and method for predicting flow characteristics
US20120144911A1 (en) * 2010-12-08 2012-06-14 Michel Moliere Wind tunnel for studying vaporization of liquids
US8656769B2 (en) * 2010-12-08 2014-02-25 Ge Energy Products France Snc Wind tunnel for studying vaporization of liquids

Also Published As

Publication number Publication date
NL7207876A (OSRAM) 1973-01-09
AT318943B (de) 1974-11-25
DE2133835C3 (de) 1975-05-07
DE2133835B2 (de) 1974-09-12
SE377843B (OSRAM) 1975-07-28
GB1382298A (en) 1975-01-29
DE2133835A1 (de) 1973-01-18
CH576636A5 (OSRAM) 1976-06-15
JPS5517329B1 (OSRAM) 1980-05-10
FR2145311A5 (OSRAM) 1973-02-16

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