Row Pattern Research Articles

Evaluating Little Millet (Panicum sumatrense L.) Based Intercropping System on Growth, Yield and Nutrient Status of Soil under Rainfed Condition

Aims: To determine the suitable component crop and its row pattern for enhancing growth and yield of little millet under intercropping system. Study Design: Randomized complete Block Design (RBD). Place and Duration of Study: The field experiment was carried out during the rabi season from October 2023 – January 2024 at Instructional north farm in Karunya Institute of Technology and Sciences, Coimbatore, Tamil Nadu. Methodology: This field experiment consists of 3 replications with eleven treatments viz., T1 – Little millet sole crop, T2 – Little millet + black gram (4:1), T3 – Little millet + black gram (6:1), T4 – Little millet + green gram (4:1), T5 – Little millet + green gram (6:1), T6 – Little millet + redgram (4:1), T7 – Little millet + redgram (6:1), T8 – Little millet + cowpea (4:1), T9 – Little millet + cowpea (6:1), T10 – Little millet + bengal gram (4:1), T11 – Little millet + bengal gram (6:1). Results: The results of the experiment showed that T2 little millet + black gram (4:1) recorded the higher growth parameters like plant height (127.6 and 133.6 cm at 60 DAS and at harvest stage) and LAI of 5.23 and 4.84 at 60 DAS and at harvest stage, respectively and also produced higher yield parameters like no.of tillers plant-1 (9) and no.of productive tillers (8) with higher grain and stover yield of 1326 and 4109 kg ha-1 and it is statistically parallel with T4 little millet + green gram (4:1). And also, nutrient uptake was highest (N – 40.8, P – 5.7 and K – 33.5 kg ha-1) in little millet + black gram (6:1). Regarding the post harvest soil fertility status, little millet + cowpea (4:1) registered the highest available NPK (339, 47.6 and 197 kg ha-1). Therefore, intercropping of black gram or green gram with little millet under rainfed condition would be the ideal recommendation.

Placement legalization for heterogeneous cells of non-integer multiple-heights

It is intuitively clear that a circuit to be implemented by selectively utilizing standard cells of various non-integer multiple-heights (NIMH) (e.g., mixed use of 6-track, 7.5-track, and 9-track cells) is able to provide a better opportunity in optimizing power, performance, and area over that by using cells of single-height only or of integer multiple-heights only. However, from the cell placement legalization point of view, the issues to be addressed for placement legalization on NIMH designs are very complex. And this paper primarily focuses on introducing novel ideas for row placement when utilizing NIMH cells, which involves determining the row pattern. The most inter-dependent and critical tasks, which are rather unique to the NIMH cell placement legalization problem, are (task 1) for the cells of the same height, distributing and assigning them to a set of distinct rows on a die and (task 2) determining the location of the rows containing cells of the same height. We solve the legalization problem by, starting from an initial row placement, iteratively solving the two tasks by formulating task 1 into an instance of row-capacity constrained network flow problem, followed by solving task 2 which leads to an optimal vertical displacement of the cells in the rows. Meanwhile, through experiments, it is shown that our network flow driven global cell assignment to rows for NIMH cell placement problem tightly linking the optimal determination of row location is able to reduce the total amount of cell displacements from the global (initial) placement by 9.5% and 51.2% in comparison with that produced by a greedy approach and the conventional state-of-the-art NIMH cell placement legalization method, respectively.

Agroeconomic differences among alternative cotton row spacings and row patterns

AbstractCrop growth and development is affected by intraspecies competition. This study was conducted to determine whether cotton productivity and profitability could be manipulated through planting geometry. The effects of row spacing, planting pattern, and variety on cotton fruit distribution, yield, and net returns were investigated near Bella Mina, AL, on a Decatur silt loam (fine, kaolinitic, thermic Rhodic Paleudults); Jackson, TN, on a Calhoun silt loam (fine‐silty, mixed, active, thermic Typic Glossaqualfs); Starkville, MS, on a Leeper silty clay loam (fine, smectitic, nonacid, thermic Vertic Epiaquepts); and Stoneville, MS, on a Bosket very fine sandy loam (fine‐loamy, mixed, active, thermic Mollic Hapludalfs). For both the 76‐ and 97‐cm row spacing, transitioning from a solid to a 2 × 1 skip row pattern reduced cotton lint yield by 19%. Reduced lint yield in the 2 × 1 skip row pattern was attributed primarily to a 7% decrease in the number of Zone 1 and first‐position bolls. Consequently, planting on a solid rather than skip row pattern increased net returns by 21%. Planting cotton in either 76‐ or 97‐cm rows using a solid rather than skip row pattern likely increases crop productivity and profitability across the US cotton belt.

Urea ammonium nitrate placement methods, row patterns, and irrigation effects on corn productivity in a humid subtropical region

AbstractCrop yields are adversely affected by nitrogen (N) losses in humid subtropical regions. This study was conducted to determine whether N dynamics could be manipulated through planting geometry and fertilizer placement. The effects of irrigation (irrigated and rainfed), row pattern (single‐ and twin‐row), and N placement (surface dribble, one knife, two knives, and control) on corn (Zea mays L.) productivity and N use efficiency were investigated at Leland, Mississippi, on a Bosket very fine sandy loam. The total N rate was split into two equal halves of 128 kg N ha−1 at V2 and V6 growth stages. The effects of row pattern and N placement were consistent between irrigated and rainfed environments. There was no interaction between row pattern and N placement nor did row pattern affect corn productivity or N use efficiency parameters. In 2020, when less than 30 mm of rainfall occurred from the first N application through 2 weeks after the last N application, corn grain yield and agronomic N efficiency were not different among placement methods and averaged 11.1 Mg ha−1 and 20.3 kg grain kg−1 fertilizer N, respectively. However, in 2021, applying N with one knife increased corn grain yield by 7% to 14% compared to the two knives and surface dribble application methods; in that year, 235 mm of rainfall occurred from the first N application through 2 weeks after the last N application. Applying N with one knife appears to consistently improve crop productivity and N use efficiency parameters for both irrigated and rainfed environments.

PENGEMBANGAN BAHAN AJAR LEMBAR KERJA SISWA BANGUN DATAR DAN BANGUN RUANG DENGAN MENGGUNAKAN POLA BARISAN

Abstract
 Mathematics is a learning that connects concepts and mathematical structures such as in flat building and space building materials. In delivering learning materials, a teacher will use teaching materials. Teaching materials are materials compiled by teachers to achieve learning objectives. The right teaching material for flat building and building space materials in class II is the Student Worksheet. With the Student Worksheet, students can increase their understanding of the material they are studying because the teaching material is designed with many pictures, practice questions, and colors. So that learning can run effectively . The method used in this study is the library method by making books, articles, journals, as references. From the research conducted, it was obtained that the teaching materials of the Student Worksheets on the material of building flat and building spaces using row patterns can be used in students of grade II Elementary School.
 Keywords: Build Flat, Build Space, Student Worksheets

PENDAPATAN MASYARAKAT DARI PROGRAM PENGELOLAAN HUTAN BERSAMA MASYARAKAT (PHBM) DENGAN SISTEM AGROFORESTRI (Studi Kasus : Desa Sumberejo BKPH Nglawungan KPH Blora Devisi Regional I Jawa Tengah Perum Perhutani)

Community based forest management is believed to be able to increase agricultural and timber products, which has economic value. Farmers generally pay more attention to economic factors than to maintaining agricultural land and forests. The level of crop productivity and the income scale of agroforestry farmers are affected by the area of agroforestry land, so it needs to be maintained. This study aims to determine the pattern of agroforestry planting and community income from the Community Forest Management (PHBM) program with an agroforestry system in Sumberejo Village BKPH Nglawungan KPH Blora Perum Perhutani Regional Division I Central Java. The method used was purposive sampling with a survey approach. The sample was selected from 6 KTH, where each is 5-7 representative respondents with criteria of the land area of ​​0.25-0.1, active members of LMDH for at least one year, and farming for at least two years as well as heads of families who were sampled in this study. The research analysis uses the Pd = TR – TC formula, and the data analysis uses descriptive analysis based on tabulations. The results showed that the community participating in PHBM in Sumberejo Village was dominated by those aged more than 30 years, with an elementary school (SD) graduate education level and livelihood as agricultural workers. Application of the pattern with an agroforestry system is with a row pattern (alternate rows). The agroforestry component is agrisilviculture, with an average farmer income of IDR 24,691,320 in a year.

Evaluation of soybean grain quality and yield across various row spacings, planting dates, and fungicide programs

AbstractOne of the major constraints to profitable soybean [Glycine max (L.) Merr.] production is yield losses caused by disease. The mid‐southern region of the United States typically experiences environmental conditions that are conducive to disease development, particularly during later reproductive growth stages. It is common for producers in this region to apply fungicides at the beginning of pod development (R3 growth stage; development of pods 3/16 inches long). Producers often question if establishing crops in different row patterns would alter the yield response to prophylactic fungicide applications. Producers also seek answers regarding the yield and grain quality responses to fungicide applications across different row patterns. However, limited data exist to determine if fungicide applications influence the responses of soybean's yield and grain quality between different row spacings. The objective of this research was to evaluate soybean's growth, development, yield, and grain quality across various row spacings, planting dates, and prophylactic fungicide application programs in the absence of disease. These data support that early‐planted soybean had greater yield than later‐planted soybean. No interactions were observed among row spacing, planting date, and fungicide product with respect to yield. Independently, no yield differences were observed regardless of the row spacing or the fungicide product. Regarding quality, soybean planted later resulted in fewer total damaged soybean kernels. These data suggest that row spacing and planting date may not influence soybean's yield response to prophylactic fungicide. Furthermore, these data also suggest that prophylactic fungicide during pod development may not influence the subsequent grain quality.

Reading Pixels Parallel and Processing Pixels Parallel (RPP-PPP): An Approach to Detecting and Tracking Objects in Static and Dynamic camera

Object detection and Tracking are important tasks in both moving and static camera applications like unmanned vehicles, human-assisted vehicles, product parts inspection, video surveillance, and many more. These applications are required to detect moving objects and track static and dynamic cameras. It also needed to process these tasks with rate and lesser time. Many computer vision applications are always used to read the image/frame pixels one by one from row by column or column by row pattern. Reading pixels one by one from the image/frame took more time in real-time applications. In this proposed method we used to read the pixels from the entire image/frame in parallel using Parallel. For utilities and process these pixels in parallel. In the proposed work we used the background subtraction model for object detection and tracking and noted the difference in both sequential and parallel processes and compared the output with the existing background subtraction model. In this work analyzed the time taken to read the entire image using various tools and languages. The work was implemented using C#.NET parallel. For other thread-based functions to minimize the pixel reading time and processing time for object detection and tracking. Finally, the proposed work gave a considerable performance and compared with the existing system.

High-Performance Row Pattern Recognition Using Joins

The SQL standard introduced MATCH_RECOGNIZE in 2016 for row pattern recognition. Since then, MATCH_RECOGNIZE has been supported by several leading relation systems, they implemented this function using Non-Deterministic Finite Automaton (NFA). While NFA is suitable for pattern recognition in streaming scenarios, the current uses of NFA by the relational systems for historical data analysis scenarios overlook important optimization opportunities. We propose a new approach to use Join to speed up row pattern recognition in historical analysis scenarios for relational systems. Implemented as a logical plan rewrite rule, the new approach first filters the input relation to MATCH_RECOGNIZE using Joins constructed based on a subset of symbols taken from the PATTERN expression, then run the NFA-based MATCH_RECOGNIZE on the filtered rows, reducing the net cost. The rule also includes a specialized cardinality model for the Joins and a cost model for the NFA-based MATCH_RECOGNIZE operator for choosing an appropriate symbol set. The rewrite rule is applicable when the query pattern's definition is self-contained and either the input table has no duplicates or there is a window condition. Applying the rewrite rule to a query benchmark with 1,800 queries spanning over 6 patterns and 3 pattern definitions, we observed median speedups of 5.4X on Trino (v373 with ORC files on Hive), 57.5X on SQL Server (2019) using column store and 41.6X on row store.

EFFECT OF PLANT DENSITY ON YIELD AND QUALITY OF PEANUT (Arachis hypogaea L.) CULTIVARS

Plant density can have a major impact on peanut (Arachis hypogaea L.) yield. Information is limited in the Eastern Mediterranean Transition Region of Turkiye on growth, development, and yield of peanut cultivars based on plant density. To address this limitation, the cultivars Aysehanim, Rigel, Halisbey, Masal, and NC 7 were established in a single row planting pattern consisting of rows spaced 70 cm apart with an inter-row plant distance of 15 cm (95.000 plants ha-1) versus a twin row planting pattern consisting of rows spaced 20 cm apart on 90 cm centers with an intra-row distance of 15 cm (148.000 plants ha-1). The interaction of cultivar × plant density was significant for most variables. Irrespective of cultivar, establishing a plant population of 148.000 plants ha-1 in the twin row planting pattern resulted in greater pod yield than the single row planting pattern with a plant density of 95.000 plants ha-1. Pod yield was similar for Rigel, Masal, and NC 7 in the twin row planting pattern and exceeded that of Aysehanim and Halisbey. Conversely, yield of Rigel and Halisbey was similar in the single row pattern and exceeded yield of Aysehanim and NC 7.

Cotton Yield and Quality Response to Row Pattern and Seeding Rate

Cotton (Gossypium hirsutum L.) is a major rotational crop associated with peanut (Arachis hypogaea L.) cropping systems in Southwest Georgia. Since peanut is typically planted in twin-rows for greater yield and grade, use of the same twin-row planter for cotton would be cost effective. It is not clear what effect row pattern would have on cotton lint yield using drip irrigation. The objectives were to compare cotton yield when planted in different row patterns, with two plant densities, at multiple locations, and irrigated with drip and sprinkler irrigation systems. Cotton was planted in single- and twin-row patterns at recommended (1X) and half-recommended (0.5X) seeding rates (93,000 and 54,600 seeds/ha, respectively). Irrigation systems were subsurface drip irrigation (SSDI), shallow subsurface drip irrigation (S3DI), and overhead sprinkler. Row pattern (single- or twin-row), seeding rate, or irrigation system had no effect on lint yield. There were fiber quality differences, probably due to cultivar, but there was no consistency to draw any conclusions. For consistent year-to-year yield and economics, it is recommended to plant cotton near 1X seeding rates using single- or twin-rows with either drip or sprinkler irrigation systems. Seeding rates reduced to half or lower than the recommended rate may increase risk of lower yields and revenue that may not be covered by money saved using less seed.

Variation of Epiphytic Flora Affecting Silage Quality in Pure and Mixed Mung Bean and Sweet Sorghum

This study was carried out to determine the microorganism population affecting silage quality of sweet sorghum and mung bean cultivated with different sowing patterns as mixture or sole crop. Twin row (20×55 cm row spacing), narrow row (55 cm row spacing) and conventional row (75 cm row spacing) were used as mixture sowing patterns. The mixtures were formed based on the plant densities and alternative row numbers of sweet sorghum and mung bean. Sowing was made on alternation rows of 1 row mung bean plus 1 row sweet sorghum (R1:1) and 1 row mung bean plus 2 rows sweet sorghum (R1:2). In pure and mixed cultivations, the plant density of sorghum was 14 plants m-2 while the plant densities of mung bean were 14, 21 and 28 plants m-2. The experiment was planned as two-factors (sowing patterns and mixtures) and was arranged in randomized blocks according to the split plot design with 3 replications. Pure and mixed plants were harvested when the sweet sorghum plant reached the dough stage. Lactic acid bacteria, enterobacteria and yeast and mold populations in the plant epiphytic flora were investigated under experimental factors. There were significant effects of the main factors and their interactions on the plant epiphytic microorganisms. According to the results obtained from the current study, mixed cultivation of sweet sorghum and mung bean in conventional row pattern improved the desired lactic acid bacteria population for silage quality, while reducing the undesirable enterobacteria and yeast and mold population for silage quality. It was determined that the (R1:2) MB14+SS14 mixed cultivation system was the most suitable mixture in conventional row pattern in terms of high lactic acid bacteria population.

Hamiltonian problems in directed graphs with simple row patterns

We define a row pattern of a matrix as a model (or a condition) to be satisfied by each row of the matrix, independently of the other rows. When applied to adjacency matrices of digraphs, a row pattern allows to define a class of digraphs characterized by a local condition on the out-neighborhood of each vertex, once an appropriate linear ordering of the vertices has been found.We show that the Hamiltonian Cycle and Hamiltonian Path problems are NP-complete on digraphs with simple row patterns, namely C1P-digraphs (where the row pattern describes the consecutive ones property), 2-out-regular digraphs (where each row contains exactly two values 1) and sym-digraphs (where the 1s in each row are symmetric with respect to the main diagonal, as soon as the row contains at least two 1s).Classes with simple row patterns thus show a real structural complexity, despite their simple definitions. Moreover, they raise interesting class recognition problems.

Does weed suppression by high crop density depend on crop spatial pattern and soil water availability?

Size-asymmetric competition, in which larger plants obtain a disproportionally larger share of contested resources, can be applied in agriculture to suppress weeds by increasing crop density and spatial uniformity, as these practices enhance the initial size-asymmetric competitive advantages of crop seedlings over weed seedlings early in the growing season. We do not yet know how agronomic factors influence weed suppression at high crop density. We performed a field experiment to ask how crop density, spatial pattern and irrigation interact to influence weed suppression and grain yield in semi-arid croplands. The experimental was a factorial design with 4 factors: wheat cultivar (Ningchun4, Xihan2), irrigation level (control, irrigated), sowing density (low, 196 seeds m−2; moderate, 400 seeds m-2; high, 625 seeds m−2), and spatial sowing pattern (rows, uniform). Weed growth was effectively suppressed by increased crop density and spatial uniformity. Effects of crop density on weed suppression and grain yield were more pronounced in the uniform pattern than in crop rows. Weed biomass was 55.7% lower and grain yield increased 29.7% higher in the high density uniform pattern compared to the low density and row pattern. Crop density interacted with cultivar in determining both weed biomass and grain yield, potentially reflecting different traits regulating crop competitive ability. Irrigation and crop density had additive effects on weed biomass but interacted to influence grain yield. Our findings support the idea that increased crop density and spatial uniformity can make a valuable and environmentally friendly contribution to weed control in wheat, reducing the need for chemical or mechanical weed control. We need a better understanding of the interactions among climate, agricultural management and crop genotype to improve our ability to effectively suppress weeds with high crop density and spatial uniformity.

Specification of Row Pattern Recognition in the SQL Standard and its Implementations

Recently, the SQL standardization Committee published a specification for support of the concept called Row Pattern Recognition in SQL. That way, the focus for the members of the Committee turned back to a kernel issue of the language, after standardizing the storage and manipulation of data formats, such as XML and JSON. In this paper we discuss the specified features using several examples and show to what extent different relational database systems as well as Data Analytics tools have integrated them. At the end of the paper, we describe the main inaccuracies of the proposal and the ways how to solve them. From our point of view, the following should be modified in one of the future proposals of the standard in relation to this concept: (a) Naming of several pattern navigation operations is inappropriate and should be changed; (b) The concept of implicit definition for row pattern variables in DEFINE should be changed to explicit; (c) The set of existing functions should be extended.

Corn yield as affected by row pattern, plant density, and irrigation system

ABSTRACT Row crops normally grown in Southeast USA are cotton (Gossypium hirsutum L.), corn (Zea mays L.), and peanut (Arachis hypogea L.) with a focus on the higher economic value for peanut. Peanut is typically planted using a twin-row pattern and purchasing a twin-row planter may not be cost effective unless used with other rotational crops. The objectives were to compare corn yield when planted in twin-rows, with two plant densities, at multiple locations, and irrigated with drip or sprinkler system. Corn was planted in single and twin-row patterns at 7.9 seeds/m (normal; 86,100 seeds/ha) and 4.9 seeds/m (half-normal; 53,600 seeds/ha) at multiple locations and cropping seasons. Irrigation systems consisted of subsurface drip (SSDI), shallow subsurface drip (S3DI) and overhead sprinkler. Single and twin-row with normal seeding rate had same yield across years, locations, or irrigation system 88% of the time. With drip irrigation only, twin-row half-normal seeding rate had the same yield as the single-row normal seeding rate 75% of the time and when factoring in seed savings had an economic benefit of $56/ha. The single-row half-normal seeding rate always had lower yield compared with other treatments. The S3DI irrigation system had greater yield than SSDI for both row patterns and seeding rates. Therefore, a twin-row planter purchased for peanut may be used to plant corn without yield reduction using normal seeding rates under either drip or sprinkler irrigation systems.

SEVERAL FACTORS THAT AFFECT CATTLE ROWING PATTERNS AS WELL AS THEIR CONTRIBUTION TO HOUSEHOLD INCOME (CASE STUDY OF LIVESTOCK FARMERS IN TAEBENU SUBDISTRICT, KUPANG REGENCY, NTT)

This study aims to analyze several factors that affect cattle rowing patterns as well as their costs, receipts and contributions to the household income of livestock farmers in Taebenu Subdistrict, Kupang Regency, NTT. The research sample of 100 people was grouped into two groups: group I (50 row cattle farmers) and group II (50 non-row cattle farmers). Determination of the number of farmer samples follows slovin formula with random sampling method. Data on factors that influence the decisions of farmers' households are analyzed with binary logistics regression analysis. Meanwhile, the income of cattle farmers and non-rowdy cattle was analyzed by household income analysis. The results showed that the analysis of binary logistics regression using simultaneous tests showed that independent variables (X) namely X1, X2, X3, X4, X5, X6 significantly influenced dependent variables (Y). The average household income of cattle farmers rowdy pattern is Rp 13,327,080 with the contribution of income from the business of cattle rowing by 21.93%, while the average household income of non-rowdy cattle farmers (privately owned) Rp 12,820,488 with the contribution of income from non-row cattle businesses amounted to 22.93%. From the results of household income shows the household income of cattle farmers row pattern higher than the household income of non-row cattle farmers (privately owned).

Additive intercropping with peanut relay-planted between different patterns of rice rows increases yield of red rice in aerobic irrigation system

Rice yields under conventional techniques are very low without high doses of commercial fertilizer application, while intercropping with legumes can increase yields. This research aimed to examine the effect of relay-planting peanut between rice rows of different patterns on yield of red rice in aerobic irrigation systems, by conducting a field experiment designed according to Split Plot design with two treatment factors, i.e. intercropping as main plots (T0= without; T1= intercropping with peanuts), and rice row patterns as sub-plots (P1= normal or single-row; P2= double-row; P3= triple-row). In T1, one row of peanut was relay-planted (additive series) between single, double, or triple rows of red rice plants three weeks after seeding red rice on raised-beds. Results indicated that additive intercropping with peanut significantly increased clump size, dry straw weight, filled panicle number, panicle length, total biomass, filled grain number, grain yield per clump, and harvest index, and reduced percentage of unfilled grains of red rice , while patterns of rice rows only affected dry straw weight, percentage of panicle number, and weight of 100 grains. However, there were significant interactions between the treatment factors on dry straw weight and percentage of panicle number, which under single-row, they were low in monocropping but high and no differences between row patterns in intercropping system. Similarly, grain yield was lower in single or double row than triple row pattern under monocropping but significantly higher and no differences between row patterns under intercropping, indicating the highest benefits of intercropping under single row pattern.

Effect of intercropping and plant distribution of sorghum with soybean on growth and yield of Sorghum bicolor

This field experiment was carried out at special farm at Luxor governorate, Egypt during 2018 and 2019 seasons to study the effect of some intercropping patterns and plant distributions of sorghum (var. Dorado) and soybean (var. Giza-111) on the growth, yield and yield components and the economic return of the sorghum plants. The experimental was laid out in split-split plot with randomized block design in three replications. The plant height of sorghum was significant affected by the different intercropping patterns and plant density in the second season only as a result of the interaction between the number of plants/ hill and the intercropping patterns. The highest values of panicle length ​​were by sole cropping of sorghum compared to the other intercropping patterns. Sowing sorghum – soybean plants as 1:1 side on the same row resulted in the highest values of panicle weight and grain yield /plant of sorghum in the mean of seasons. Sowing of sorghum as sole crop at 15 cm between hills plus two plants /hill followed by 4:2 row intercropping gave the highest values of grain weight /plot and grain yield /feddan (feddan = 0.420 hectares = 1.037 acres) in the two seasons compared to the other treatments. The highest value of land equivalent ratio (1.41) resulted from the use of 3:3 row pattern of intercropping with two plants /hill and 15 cm spacing. Also, there is an increase in the value of the land equivalent ratio (1.29) with the use of the 4:2 row pattern of sorghum-soybean intercropping with 2 plants /hill and 15 cm between hills. The most profitable system was intercropping of sorghum: soybean as 3: 3 or 4:2 row patterns and 15 or 20 cm between hills with planting two plants /hill.

Comparisons of Endwall Overall Effectiveness From Two Film Hole Distribution Patterns at Low and High Exit Mach Numbers

Abstract In this paper, detailed overall cooling effectiveness and associated flow patterns are presented for two distinct film hole distribution patterns over a turbine endwall: an axial-row pattern and an iso-Mach number line row pattern. Measurements, in combination with numerical simulations, are performed in a scaled-up cascade. Thermal protection for the endwall is achieved by jet-array impingement on the cold side and discrete film cooling on the hot-gas side, combined with purge air from an inclined slot that simulates the upstream seal cavity. Infrared (IR) thermography techniques are used to obtain overall effectiveness in a wide range of coolant flow ratios of 1.5–3.8%. Mach numbers at the exit of the vane cascade are 0.25 and 0.70, representing the variations of engine operating conditions. Overall effectiveness measurements and computational flowfields show that the iso-Mach number line hole pattern outperforms the hole pattern with axial rows of holes in terms of overall effectiveness levels and thermodynamic energy losses, regardless of coolant flow ratios. Increasing Mach number increases overall effectiveness levels on the endwall and higher Mach numbers generate higher effectiveness improvement for the iso-Mach number line arrangement, relative to the axial-row configuration. Additionally, adding purge air to the endwall considerably improves the overall effectiveness levels and purge air performs better for the axial-row pattern due to no direct interactions with downstream discrete coolant injection.