http://yetl.yabesh.ir/yetl1/handle/yetl/4298015 2026-08-25T23:34:06Z 2026-08-25T23:34:06Z Silva, Vinícius C. Lopes, André B. http://yetl.yabesh.ir/yetl1/handle/yetl/4316903 2026-08-23T08:41:37Z 2026-01-01T00:00:00Z

An Analytic Benchmark for H1 Heat Transfer With Slip in an Equilateral Triangular Duct Silva, Vinícius C.; Lopes, André B. Abstract. We derive a fully analytic benchmark for thermally fully developed H1 heat transfer with slip in an equilateral triangular duct. The result complements the semi-analytic benchmark data reported by Wang (2013) (“Benchmark Solutions for Slip Flow and H1 Heat Transfer in Rectangular and Equilateral Triangular Ducts,” ASME J. Heat Mass Transfer-Trans. ASME 135(2), p. 021703). For the classical no temperature-jump limit γ=0, the temperature field is obtained via an eigenfunction expansion built from threefold symmetric Dirichlet modes. The associated energy integral is evaluated in closed form, leading to an explicit Nusselt-number formula. Representative values are tabulated and provide a convenient reference for numerical verification.

2026-01-01T00:00:00Z Capobianchi, Massimo Cangelosi, Richard http://yetl.yabesh.ir/yetl1/handle/yetl/4316898 2026-08-23T08:41:19Z 2026-01-01T00:00:00Z

Efficiency of Thick, Cylindrical Pin Fins Capobianchi, Massimo; Cangelosi, Richard Abstract. This study computes the fin efficiency of thick, cylindrical pin fins with insulated tips, that is, cylindrical pin fins where radial-direction conduction within the fin is significant. For such fins, two-dimensional analyses are required as traditional one-dimensional (i.e., thin fin) solutions are inapplicable. Curves of constant thick fin efficiency are mapped on plots of the Biot number versus fin aspect ratio, which are the only two parameters in the thick fin problem. The efficiency is also conveniently calculated by adjusting the analogous thin fin efficiency utilizing a correction factor. Curves of constant correction factors are thus similarly mapped. The thick fin efficiency is therefore easily determined directly from knowledge of only those two parameters, thereby allowing the direct, manual computation of the thick fin performance.

2026-01-01T00:00:00Z Mamadou, A. F. I. Idrissou, M. O. K. Sanya, S. A. O. Pitz, D. B. Sanoussi, B. R. Vargas, J. V. C. Ordonez, J. C. http://yetl.yabesh.ir/yetl1/handle/yetl/4316891 2026-08-23T08:41:01Z 2026-01-01T00:00:00Z

Numerical Optimal Control of Endoreversible Single-Effect HVAC-AR System Based on Finite-Time Thermodynamic Method Mamadou, A. F. I.; Idrissou, M. O. K.; Sanya, S. A. O.; Pitz, D. B.; Sanoussi, B. R.; Vargas, J. V. C.; Ordonez, J. C. Abstract. For static thermodynamic systems, analytical-geometric and variational principles are used so far for optimal control in finite-time thermodynamic (FTT)-based engineering optimization problems. This solution technique has some limitations, as is the case for single-effect refrigeration absorption heating, ventilation, and air conditioning (HVAC-AR) systems thermodynamic optimization, whose problem is to optimally allocate thermal conductances in the four heat exchangers. Hence the need to explore numerical methods as an alternative solution. This paper proposes a model combining FTT–linear programing (LP) to succinctly formulate the optimization problem of HVAC-AR systems with constraints, where the thermal conductances of the four heat exchangers are the design parameters and the objective function is the cooling load. Interior-point (IP) numerical method was used to solve the optimization problem formulated. The simulation carried out shows the performance improvement of HVAC-AR system under real operation conditions. The results are validated based on previous literature.

2026-01-01T00:00:00Z Panse, Sanskar S. Ekkad, Srinath V. http://yetl.yabesh.ir/yetl1/handle/yetl/4316883 2026-08-23T08:40:36Z 2026-01-01T00:00:00Z

Experimental And Numerical Evaluation of Oblique Angle and Secondary Channel Width on Heat Transfer and Pressure Drop of Oblique Microchannels Panse, Sanskar S.; Ekkad, Srinath V. Abstract. Increase in heat dissipation from micro-electronics has necessitated the development of enhanced microchannel geometries capable of providing high heat flux cooling while maintaining optimal device temperatures. To this end, this study investigates the thermal and hydraulic behavior of oblique microchannels (OMC) featuring oblique discontinuities in otherwise continuous channel walls to enhance fluid mixing and maintain the coolant in a continuous state of thermal and hydrodynamic development, aimed at improving the overall performance. A combined experimental and numerical study is undertaken to analyze the interplay between the oblique angle (θ) and the oblique channel width (W0) on heat transfer and pressure drop characteristics of OMC. Detailed analysis of numerically derived local fluid flow and heat transfer behavior is presented to corroborate the findings. Results show the thermal and hydraulic performance is strongly governed by oblique angle than by secondary channel width. Smaller oblique angles and wider secondary channels encourage stronger secondary flow momentum which enhances fluid mixing and thereby, heat transfer performance. The local heat transfer was found to be a strong function of the microchannel's ability to generate secondary flows. Numerical parametric study reveals that the choice of oblique angle and secondary channel width dictates the surface area available for heat transfer, momentum of secondary flows, and thus, channel-to-channel fluid mixing, which ultimately influences the thermal and hydraulic performance of OMC.

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